@article{amaya_manley_bian_rutland_leschinsky_ratigan_makris_2024, title={Enhancing ferryl accumulation in H2O2-dependent cytochrome P450s}, volume={252}, ISSN={["1873-3344"]}, DOI={10.1016/j.jinorgbio.2023.112458}, abstractNote={A facile strategy is presented to enhance the accumulation of ferryl (iron(IV)-oxo) species in H2O2 dependent cytochrome P450s (CYPs) of the CYP152 family. We report the characterization of a highly chemoselective CYP decarboxylase from Staphylococcus aureus (OleTSA) that is soluble at high concentrations. Examination of OleTSA Compound I (CpdI) accumulation with a variety of fatty acid substrates reveals a dependence on resting spin-state equilibrium. Alteration of this equilibrium through targeted mutagenesis of the proximal pocket favors the high-spin form, and as a result, enhances Cpd-I accumulation to nearly stoichiometric yields.}, journal={JOURNAL OF INORGANIC BIOCHEMISTRY}, author={Amaya, Jose A. and Manley, Olivia M. and Bian, Julia C. and Rutland, Cooper D. and Leschinsky, Nicholas and Ratigan, Steven C. and Makris, Thomas M.}, year={2024}, month={Mar} }
 @article{gering_li_tang_swartz_chang_makris_2023, title={A Ferric-Superoxide Intermediate Initiates P450-Catalyzed Cyclic Dipeptide Dimerization}, volume={8}, ISSN={["1520-5126"]}, url={https://doi.org/10.1021/jacs.3c04542}, DOI={10.1021/jacs.3c04542}, abstractNote={The cytochrome P450 (CYP) AspB is involved in the biosynthesis of the diketopiperazine (DKP) aspergilazine A. Tryptophan-linked dimeric DKP alkaloids are a large family of natural products that are found in numerous species and exhibit broad and often potent bioactivity. The proposed mechanisms for C-N bond formation by AspB, and similar C-C bond formations by related CYPs, have invoked the use of a ferryl-intermediate as an oxidant to promote substrate dimerization. Here, the parallel application of steady-state and transient kinetic approaches reveals a very different mechanism that involves a ferric-superoxide species as a primary oxidant to initiate DKP-assembly. Single turnover kinetic isotope effects and a substrate analog suggest the probable nature and site for abstraction. The direct observation of CYP-superoxide reactivity rationalizes the atypical outcome of AspB and reveals a new reaction manifold in heme enzymes.}, journal={JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, author={Gering, Hannah E. and Li, Xiaojun and Tang, Haoyu and Swartz, Paul D. and Chang, Wei-Chen and Makris, Thomas M.}, year={2023}, month={Aug} }
 @article{rade_generoso_das_souza_silveira_avila_vieira_miyamoto_lima_aricetti_et al._2023, title={Dimer-assisted mechanism of (un)saturated fatty acid decarboxylation for alkene production}, volume={120}, ISSN={["1091-6490"]}, DOI={10.1073/pnas.2221483120}, abstractNote={
            The enzymatic decarboxylation of fatty acids (FAs) represents an advance toward the development of biological routes to produce drop-in hydrocarbons. The current mechanism for the P450-catalyzed decarboxylation has been largely established from the bacterial cytochrome P450 OleT
            JE
            . Herein, we describe OleTP
            RN
            , a poly-unsaturated alkene-producing decarboxylase that outrivals the functional properties of the model enzyme and exploits a distinct molecular mechanism for substrate binding and chemoselectivity. In addition to the high conversion rates into alkenes from a broad range of saturated FAs without dependence on high salt concentrations, OleTP
            RN
            can also efficiently produce alkenes from unsaturated (oleic and linoleic) acids, the most abundant FAs found in nature. OleTP
            RN
            performs carbon–carbon cleavage by a catalytic itinerary that involves hydrogen-atom transfer by the heme-ferryl intermediate Compound I and features a hydrophobic cradle at the distal region of the substrate-binding pocket, not found in OleT
            JE
            , which is proposed to play a role in the productive binding of long-chain FAs and favors the rapid release of products from the metabolism of short-chain FAs. Moreover, it is shown that the dimeric configuration of OleTP
            RN
            is involved in the stabilization of the A-A’ helical motif, a second-coordination sphere of the substrate, which contributes to the proper accommodation of the aliphatic tail in the distal and medial active-site pocket. These findings provide an alternative molecular mechanism for alkene production by P450 peroxygenases, creating new opportunities for biological production of renewable hydrocarbons.
          }, number={22}, journal={PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA}, author={Rade, Leticia L. and Generoso, Wesley C. and Das, Suman and Souza, Amanda S. and Silveira, Rodrigo L. and Avila, Mayara C. and Vieira, Plinio S. and Miyamoto, Renan Y. and Lima, Ana B. B. and Aricetti, Juliana A. and et al.}, year={2023}, month={May} }
 @article{phan_manley_skirboll_cha_hilovsky_chang_thompson_liu_makris_2023, title={Excision of a Protein-Derived Amine for <i>p</i>-Aminobenzoate Assembly by the Self-Sacrificial Heterobimetallic Protein CADD}, volume={62}, ISSN={["1520-4995"]}, url={https://doi.org/10.1021/acs.biochem.3c00406}, DOI={10.1021/acs.biochem.3c00406}, abstractNote={Chlamydia protein associating with death domains (CADD), the founding member of a recently discovered class of nonheme dimetal enzymes termed hemeoxygenase-like dimetaloxidases (HDOs), plays an indispensable role in pathogen survival. CADD orchestrates the biosynthesis of p-aminobenzoic acid (pABA) for integration into folate via the self-sacrificial excision of a protein-derived tyrosine (Tyr27) and several additional processing steps, the nature and timing of which have yet to be fully clarified. Nuclear magnetic resonance (NMR) and proteomics approaches reveal the source and probable timing of amine installation by a neighboring lysine (Lys152). Turnover studies using limiting O2 have identified a para-aminobenzaldehyde (pABCHO) metabolic intermediate that is formed on the path to pABA formation. The use of pABCHO and other probe substrates shows that the heterobimetallic Fe/Mn form of the enzyme is capable of oxygen insertion to generate the pABA-carboxylate.}, number={22}, journal={BIOCHEMISTRY}, author={Phan, Han N. and Manley, Olivia M. and Skirboll, Sydney S. and Cha, Lide and Hilovsky, Dalton and Chang, Wei-chen and Thompson, Peter M. and Liu, Xiaojing and Makris, Thomas M.}, year={2023}, month={Nov}, pages={3276–3282} }
 @article{islam_park_manley_smith_makris_peryshkov_2023, title={Room-Temperature Aerobic C-CN Bond Activation in Nickel(II) Cyanomethyl Dicarboranyl Complex}, volume={7}, ISSN={["1520-6041"]}, url={https://doi.org/10.1021/acs.organomet.3c00216}, DOI={10.1021/acs.organomet.3c00216}, abstractNote={We report the synthesis and characterization of a nickel(II) complex of the dicarboranyl CNC dianionic pincer ligand, which activates acetonitrile by C–C bond cleavage. Deprotonation of the relatively acidic C–H bond of the coordinated acetonitrile with potassium t-butoxide led to the formation of the C-bound cyanomethylene ligand at the metal center. Unlike most previously characterized Ni(II) cyanoalkyls, the resulting complex exhibited quick transformation under aerobic conditions at room temperature to afford CNC-ligated nickel(II) cyanide, indicating facile cleavage of the C–CN bond. The cyanoalkyl and cyanide complexes were isolated in excellent yields and characterized by NMR spectroscopy and single-crystal X-ray diffraction. Carbon-containing products of the aerobic C–CN bond activation are hydroxyacetonitrile, formaldehyde, cyanomethyl formate, and carbon dioxide.}, journal={ORGANOMETALLICS}, author={Islam, Mohammad Jahirul and Park, Kyoung Chul and Manley, Olivia M. M. and Smith, Mark D. D. and Makris, Thomas M. M. and Peryshkov, Dmitry V. V.}, year={2023}, month={Jul} }
 @article{dutra_amaya_mcelhenney_manley_makris_rassolov_garashchuk_2022, title={Experimental and Theoretical Examination of the Kinetic Isotope Effect in Cytochrome P450 Decarboxylase OleT}, volume={126}, ISSN={["1520-5207"]}, url={https://doi.org/10.1021/acs.jpcb.1c10280}, DOI={10.1021/acs.jpcb.1c10280}, abstractNote={Using a combination of experimental studies, theory, simulation, and modeling, we investigate the hydrogen atom transfer (HAT) reaction by the high-valent ferryl cytochrome P450 (CYP) intermediate known as Compound I, a species that is central to innumerable and important detoxification and biosynthetic reactions. The P450 decarboxylase known as OleT converts fatty acids, a sustainable biological feedstock, into terminal alkenes and thus is of high interest as a potential means to produce fungible biofuels. Previous experimental work has established the intermediacy of Compound I in the C─C scission reaction catalyzed by OleT and an unprecedented ability to monitor the HAT process in the presence of bound fatty acid substrates. Here, we leverage the kinetic simplicity of the OleT system to measure the activation barriers for CYP HAT and the temperature dependence of the substrate 2H kinetic isotope effect. Notably, neither measurement has been previously accessible for a CYP to date. Theoretical analysis alludes to the significance of substrate fatty acid coordination for generating the hydrogen donor/acceptor configurations that are most conducive for HAT to occur. The analysis of the two-dimensional potential energy surface, based on multireference electronic wave functions, illustrates the uncoupled character of the hydrogen motion. Quantum dynamics calculations along the hydrogen reaction path demonstrate that hydrogen tunneling is essential to qualitatively capture the experimental isotope effect, its temperature dependence, and appropriate activation energies. Overall, a more fundamental understanding of the OleT reaction coordinate contributes to the development of biomimetic catalysts for controlled C─H bond activation, an outstanding current challenge for (bio)synthetic chemistry.}, number={19}, journal={JOURNAL OF PHYSICAL CHEMISTRY B}, author={Dutra, Matthew and Amaya, Jose A. and McElhenney, Shannon and Manley, Olivia M. and Makris, Thomas M. and Rassolov, Vitaly and Garashchuk, Sophya}, year={2022}, month={May}, pages={3493–3504} }
 @article{dutra_mcelhenney_manley_makris_rassolov_garashchuk_2022, title={Modeling the Ligand Effect on the Structure of CYP 450 Within the Density Functional Theory}, volume={126}, ISSN={["1520-5215"]}, url={https://doi.org/10.1021/acs.jpca.2c01783}, DOI={10.1021/acs.jpca.2c01783}, abstractNote={An improved understanding of the P450 structure is relevant to the development of biomimetic catalysts and inhibitors for controlled CH-bond activation, an outstanding challenge of synthetic chemistry. Motivated by the experimental findings of an unusually short Fe-S bond of 2.18 Å for the wild-type (WT) OleT P450 decarboxylase relative to a cysteine pocket mutant form (A369P), a computational model that captures the effect of the thiolate axial ligand on the iron-sulfur distance is presented. With the computational efficiency and streamlined analysis in mind, this model combines a cluster representation of the enzyme─40-110 atoms, depending on the heme and ligand truncation level─with a density functional theory (DFT) description of the electronic structure (ES) and is calibrated against the experimental data. The optimized Fe-S distances show a difference of 0.25 Å between the low and high spin states, in agreement with the crystallographic structures of the OleT WT and mutant forms. We speculate that this difference is attributable to the packing of the ligand; the mutant is bulkier due to an alanine-to-proline replacement, meaning that it is excluded from the energetically favored low-spin minimum because of steric constraints. The presence of pure spin-state pairs and the intersection of the low/high spin states for the enzyme model is indicative of the limitations of single-reference ES methods in such systems and emphasizes the significance of using the proper state when modeling the hydrogen atom transfer (HAT) reaction catalyzed by OleT. At the same time, the correct characterization of both the short and long Fe-S bonds within a small DFT-based model of 42 atoms paves the way for quantum dynamics modeling of the HAT step, which initiates the OleT decarboxylation reaction.}, number={18}, journal={JOURNAL OF PHYSICAL CHEMISTRY A}, publisher={American Chemical Society (ACS)}, author={Dutra, Matthew and McElhenney, Shannon and Manley, Olivia and Makris, Tom and Rassolov, Vitaly and Garashchuk, Sophya}, year={2022}, month={May}, pages={2818–2824} }
 @article{manley_phan_stewart_mosley_xue_cha_bai_lightfoot_rucker_collins_et al._2022, title={Self-sacrificial tyrosine cleavage by an Fe:Mn oxygenase for the biosynthesis of para-aminobenzoate in Chlamydia trachomatis}, volume={119}, ISSN={["1091-6490"]}, url={http://dx.doi.org/10.1073/pnas.2210908119}, DOI={10.1073/pnas.2210908119}, abstractNote={
            Chlamydia protein associating with death domains (CADD) is involved in the biosynthesis of
            para
            -aminobenzoate (pABA), an essential component of the folate cofactor that is required for the survival and proliferation of the human pathogen
            Chlamydia trachomatis
            . The pathway used by
            Chlamydiae
            for pABA synthesis differs from the canonical multi-enzyme pathway used by most bacteria that relies on chorismate as a metabolic precursor. Rather, recent work showed pABA formation by CADD derives from
            l
            -tyrosine. As a member of the emerging superfamily of heme oxygenase–like diiron oxidases (HDOs), CADD was proposed to use a diiron cofactor for catalysis. However, we report maximal pABA formation by CADD occurs upon the addition of both iron and manganese, which implicates a heterobimetallic Fe:Mn cluster is the catalytically active form. Isotopic labeling experiments and proteomics studies show that CADD generates pABA from a protein-derived tyrosine (Tyr27), a residue that is ∼14 Å from the dimetal site. We propose that this self-sacrificial reaction occurs through O
            2
            activation by a probable Fe:Mn cluster through a radical relay mechanism that connects to the “substrate” Tyr, followed by amination and direct oxygen insertion. These results provide the molecular basis for pABA formation in
            C. trachomatis
            , which will inform the design of novel therapeutics.
          }, number={39}, journal={PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA}, publisher={Proceedings of the National Academy of Sciences}, author={Manley, Olivia M. and Phan, Han N. and Stewart, Allison K. and Mosley, Dontae A. and Xue, Shan and Cha, Lide and Bai, Hongxia and Lightfoot, Veda C. and Rucker, Pierson A. and Collins, Leonard and et al.}, year={2022}, month={Sep} }
 @article{martin_park_leith_yu_mathur_wilson_gange_barth_ly_manley_et al._2022, title={Stimuli-Modulated Metal Oxidation States in Photochromic MOFs}, volume={144}, ISSN={["1520-5126"]}, DOI={10.1021/jacs.1c11984}, abstractNote={Tuning metal oxidation states in metal-organic framework (MOF) nodes by switching between two discrete linker photoisomers via an external stimulus was probed for the first time. On the examples of three novel photochromic copper-based frameworks, we demonstrated the capability of switching between +2 and +1 oxidation states, on demand. In addition to crystallographic methods used for material characterization, the role of the photochromic moieties for tuning the oxidation state was probed via conductivity measurements, cyclic voltammetry, and electron paramagnetic resonance, X-ray photoelectron, and diffuse reflectance spectroscopies. We confirmed the reversible photoswitching activity including photoisomerization rate determination of spiropyran- and diarylethene-containing linkers in extended frameworks, resulting in changes in metal oxidation states as a function of alternating excitation wavelengths. To elucidate the switching process between two states, the photoisomerization quantum yield of photochromic MOFs was determined for the first time. Overall, the introduced noninvasive concept of metal oxidation state modulation on the examples of stimuli-responsive MOFs foreshadows a new pathway for alternation of material properties toward targeted applications.}, number={10}, journal={JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, author={Martin, Corey R. and Park, Kyoung Chul and Leith, Gabrielle A. and Yu, Jierui and Mathur, Abhijai and Wilson, Gina R. and Gange, Gayathri B. and Barth, Emily L. and Ly, Richard T. and Manley, Olivia M. and et al.}, year={2022}, month={Mar}, pages={4457–4468} }
 @article{daneshian_renggli_hanaway_offermann_schlachter_henry_prakash_wybouw_dermauw_shimizu_et al._2022, title={Structural and functional characterization of beta-cyanoalanine synthase from Tetranychus urticae}, volume={142}, ISSN={["1879-0240"]}, DOI={10.1016/j.ibmb.2022.103722}, abstractNote={Tetranychus urticae is a polyphagous spider mite that can feed on more than 1100 plant species including cyanogenic plants. The herbivore genome contains a horizontally acquired gene tetur10g01570 (TuCAS) that was previously shown to participate in cyanide detoxification. To understand the structure and determine the function of TuCAS in T. urticae, crystal structures of the protein with lysine conjugated pyridoxal phosphate (PLP) were determined. These structures reveal extensive TuCAS homology with the β-substituted alanine synthase family, and they show that this enzyme utilizes a similar chemical mechanism involving a stable α-aminoacrylate intermediate in β-cyanoalanine and cysteine synthesis. We demonstrate that TuCAS is more efficient in the synthesis of β-cyanoalanine, which is a product of the detoxification reaction between cysteine and cyanide, than in the biosynthesis of cysteine. Also, the enzyme carries additional enzymatic activities that were not previously described. We show that TuCAS can detoxify cyanide using O-acetyl-L-serine as a substrate, leading to the direct formation of β-cyanoalanine. Moreover, it catalyzes the reaction between the TuCAS-bound α-aminoacrylate intermediate and aromatic compounds with a thiol group. In addition, we have tested several compounds as TuCAS inhibitors. Overall, this study identifies additional functions for TuCAS and provides new molecular insight into the xenobiotic metabolism of T. urticae.}, journal={INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY}, author={Daneshian, Leily and Renggli, Isabella and Hanaway, Ryan and Offermann, Lesa R. and Schlachter, Caleb R. and Henry, Shannon and Prakash, Rahul and Wybouw, Nicky and Dermauw, Wannes and Shimizu, Linda S. and et al.}, year={2022}, month={Mar} }
 @article{manley_tang_xue_guo_chang_makris_2021, title={BesC Initiates C-C Cleavage through a Substrate-Triggered and Reactive Diferric-Peroxo Intermediate}, volume={12}, ISSN={["1520-5126"]}, url={https://doi.org/10.1021/jacs.1c11109}, DOI={10.1021/jacs.1c11109}, abstractNote={BesC catalyzes the iron- and O2-dependent cleavage of 4-chloro-l-lysine to form 4-chloro-l-allylglycine, formaldehyde, and ammonia. This process is a critical step for a biosynthetic pathway that generates a terminal alkyne amino acid which can be leveraged as a useful bio-orthogonal handle for protein labeling. As a member of an emerging family of diiron enzymes that are typified by their heme oxygenase-like fold and a very similar set of coordinating ligands, recently termed HDOs, BesC performs an unusual type of carbon-carbon cleavage reaction that is a significant departure from reactions catalyzed by canonical dinuclear-iron enzymes. Here, we show that BesC activates O2 in a substrate-gated manner to generate a diferric-peroxo intermediate. Examination of the reactivity of the peroxo intermediate with a series of lysine derivatives demonstrates that BesC initiates this unique reaction trajectory via cleavage of the C4-H bond; this process represents the rate-limiting step in a single turnover reaction. The observed reactivity of BesC represents the first example of a dinuclear-iron enzyme that utilizes a diferric-peroxo intermediate to capably cleave a C-H bond as part of its native function, thus circumventing the formation of a high-valent intermediate more commonly associated with substrate monooxygenations.}, journal={JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, publisher={American Chemical Society (ACS)}, author={Manley, Olivia M. and Tang, Haoyu and Xue, Shan and Guo, Yisong and Chang, Wei-chen and Makris, Thomas M.}, year={2021}, month={Dec} }
 @article{metavarayuth_ejegbavwo_mccarver_myrick_makris_vogiatzis_senanayake_manley_ebrahim_frenkel_et al._2020, title={Direct Identification of Mixed-Metal Centers in Metal-Organic Frameworks: Cu<inf>3</inf>(BTC)<inf>2</inf>Transmetalated with Rh<sup>2+</sup>Ions}, volume={11}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85092682422&partnerID=MN8TOARS}, DOI={10.1021/acs.jpclett.0c02539}, abstractNote={Raman spectroscopy has been used to establish direct evidence of heterometallic metal centers in a metal-organic framework (MOF). The Cu3(BTC)2 MOF (HKUST-1, BTC3-=benzenetricarboxylate) MOF was transmetallated by heating in a solution of RhCl3 to substitute Rh2+ ions for Cu2+ ions. In addition to the Cu-Cu and Rh-Rh stretching modes, Raman spectra of (CuxRh1-x)3(BTC)2 show the Cu-Rh stretching mode, indicating that mixed metal Cu-Rh nodes are formed after transmetallation. DFT studies confirm the assignment of a Raman peak at 285 cm-1 to ν(Cu-Rh). Electron paramagnetic resonance (EPR) spectroscopy experiments further support the conclusion that Rh2+ ions are substituted into the paddle-wheel nodes of the Cu3(BTC)2 to form an isostructural heterometallic MOF, and electron microscopy studies show that Rh and Cu are homogenously distributed in CuRhBTC on the nanoscale.}, number={19}, journal={Journal of Physical Chemistry Letters}, publisher={American Chemical Society (ACS)}, author={Metavarayuth, Kamolrat and Ejegbavwo, Otega and McCarver, Gavin and Myrick, Michael L. and Makris, Thomas M. and Vogiatzis, Konstantinos D. and Senanayake, Sanjaya D. and Manley, Olivia M. and Ebrahim, Amani M. and Frenkel, Anatoly I. and et al.}, year={2020}, pages={8138–8144} }
 @article{zhang_manley_ma_yin_makris_wang_2020, title={Enhanced P450 fatty acid decarboxylase catalysis by glucose oxidase coupling and co-assembly for biofuel generation}, volume={311}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85085509345&partnerID=MN8TOARS}, DOI={10.1016/j.biortech.2020.123538}, abstractNote={Cytochrome P450 OleT is a fatty acid decarboxylase that uses hydrogen peroxide (H2O2) to catalyze the production of terminal alkenes, which are industrially important chemicals with biofuel and synthetic applications. Despite its requirement for large turnover levels, high concentrations of H2O2 may cause heme group degradation, diminishing enzymatic activity and limiting broad application for synthesis. Here, we report an artificial enzyme cascade composed of glucose oxidase (GOx) and OleTSA from Staphylococcus aureus for efficient terminal alkene production. By adjusting the ratio of GOx to OleTSA, the GOx-based tandem catalysis shows significantly improved product yield compared to the H2O2 injection method. Moreover, the co-assembly of the GOx/OleTSA enzymes with a polymer, forming polymer-dual enzymes nanoparticles, displays improved activity compared to the free enzyme. This dual strategy provides a simple and efficient system to transform a naturally abundant feedstock to industrially important chemicals.}, journal={Bioresource Technology}, author={Zhang, L. and Manley, O.M. and Ma, D. and Yin, Y. and Makris, T.M. and Wang, Q.}, year={2020} }
 @article{zhang_beatty_lu_abdalrahman_makris_wang_wang_2020, title={Microfluidic-assisted polymer-protein assembly to fabricate homogeneous functionalnanoparticles}, volume={111}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85081021158&partnerID=MN8TOARS}, DOI={10.1016/j.msec.2020.110768}, abstractNote={Functional polymer-protein nanoparticles (NPs) have broad applications in biotechnology and nanotechnology. In principle, controllable and vigorous mixing is required to fabricate homogeneous NPs, which remains a challenge via conventional bulk synthetic methods. In this study, an electrokinetics (EK) based microfluidic reactor with fast mixing is explored to assemble functional proteins with polymers in an ethanol/water co-solvent system. The resultant NPs show significantly improved size distribution by comparison with the ones prepared using conventional bulk method, while the NPs size can be tuned by adjusting the mass ratio of polymer to protein. The functionalities of the assembled proteins are sustained upon the EK based microfluidic mixing, indicating the application potential of our method in the controlled assembly of different functional proteins.}, journal={Materials Science and Engineering C}, author={Zhang, L. and Beatty, A. and Lu, L. and Abdalrahman, A. and Makris, T.M. and Wang, G. and Wang, Q.}, year={2020} }
 @inbook{makris_2019, title={CHAPTER 6: Cytochrome P450 Decarboxylases}, volume={2019-January}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85056608206&partnerID=MN8TOARS}, DOI={10.1039/9781788012911-00127}, abstractNote={The cytochrome P450 OleT catalyzes the H2O2-dependent conversion of fatty acids to 1-olefins and carbon dioxide. The atypical nature of this reaction, coupled with its potential for sustainable fuel synthesis, has generated a great deal of interest since its discovery. The intriguing molecular mechanism of OleT and its potential for fungible fuel production is reviewed, revealing an interesting deviation from the activated oxygen-rebound chemistry that is common to most P450 monooxygenases.}, number={13}, booktitle={RSC Metallobiology}, author={Makris, T.M.}, year={2019}, pages={127–143} }
 @article{blahut_wise_bruno_dong_makris_frantom_dunkle_outten_2019, title={Direct observation of intermediates in the SufS cysteine desulfurase reaction reveals functional roles of conserved active-site residues}, volume={294}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85070772319&partnerID=MN8TOARS}, DOI={10.1074/jbc.RA119.009471}, abstractNote={Iron-sulfur (Fe-S) clusters are necessary for the proper functioning of numerous metalloproteins. Fe-S cluster (Isc) and sulfur utilization factor (Suf) pathways are the key biosynthetic routes responsible for generating these Fe-S cluster prosthetic groups in Escherichia coli. Although Isc dominates under normal conditions, Suf takes over during periods of iron depletion and oxidative stress. Sulfur acquisition via these systems relies on the ability to remove sulfur from free cysteine using a cysteine desulfurase mechanism. In the Suf pathway, the dimeric SufS protein uses the cofactor pyridoxal 5′-phosphate (PLP) to abstract sulfur from free cysteine, resulting in the production of alanine and persulfide. Despite much progress, the stepwise mechanism by which this PLP-dependent enzyme operates remains unclear. Here, using rapid-mixing kinetics in conjunction with X-ray crystallography, we analyzed the pre-steady-state kinetics of this process while assigning early intermediates of the mechanism. We employed H123A and C364A SufS variants to trap Cys-aldimine and Cys-ketimine intermediates of the cysteine desulfurase reaction, enabling direct observations of these intermediates and associated conformational changes of the SufS active site. Of note, we propose that Cys-364 is essential for positioning the Cys-aldimine for Cα deprotonation, His-123 acts to protonate the Ala-enamine intermediate, and Arg-56 facilitates catalysis by hydrogen bonding with the sulfhydryl of Cys-aldimine. Our results, along with previous SufS structural findings, suggest a detailed model of the SufS-catalyzed reaction from Cys binding to C–S bond cleavage and indicate that Arg-56, His-123, and Cys-364 are critical SufS residues in this C–S bond cleavage pathway.}, number={33}, journal={Journal of Biological Chemistry}, author={Blahut, M. and Wise, C.E. and Bruno, M.R. and Dong, G. and Makris, T.M. and Frantom, P.A. and Dunkle, J.A. and Outten, F.W.}, year={2019}, pages={12444–12458} }
 @article{manley_fan_guo_makris_2019, title={Oxidative Decarboxylase UndA Utilizes a Dinuclear Iron Cofactor}, volume={141}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85066785841&partnerID=MN8TOARS}, DOI={10.1021/jacs.9b02545}, abstractNote={UndA is a nonheme iron enzyme that activates oxygen to catalyze the decarboxylation of dodecanoic acid to undecene and carbon dioxide. We report the first optical and Mössbauer spectroscopic characterization of UndA, revealing that the enzyme harbors a coupled dinuclear iron cluster. Single turnover studies confirm that the reaction of the diferrous enzyme with dioxygen produces stoichiometric product per cluster. UndA is the first characterized example of a diiron decarboxylase, thus expanding the repertoire of reactions catalyzed by dinuclear iron enzymes.}, number={22}, journal={Journal of the American Chemical Society}, publisher={American Chemical Society (ACS)}, author={Manley, Olivia M. and Fan, Ruixi and Guo, Yisong and Makris, Thomas M.}, year={2019}, pages={8684–8688} }
 @article{kader_monavarian_barati_moeinzadeh_makris_jabbari_2019, title={Plasmin-Cleavable Nanoparticles for On-Demand Release of Morphogens in Vascularized Osteogenesis}, volume={20}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85071342559&partnerID=MN8TOARS}, DOI={10.1021/acs.biomac.9b00532}, abstractNote={The objective of this work was to engineer self-assembled nanoparticles (NPs) for on-demand release of bone morphogenetic protein-2 (BMP2) and vascular endothelial growth factor (VEGF) in response to enzymes secreted by the migrating human mesenchymal stem cells (hMSCs) and human endothelial colony forming cells (ECFCs) to induce osteogenesis and vasculogenesis. Gene expression profiling experiments revealed that hMSCs and ECFCs, encapsulated in osteogenic/vasculogenic hydrogels, expressed considerable levels of plasminogen, urokinase plasminogen activator and its receptor uPAR, and tissue plasminogen activator. Therefore, the plasmin-cleavable lysine-phenylalanine-lysine-threonine (KFKT) was used to generate enzymatically cleavable NPs. The acetyl-terminated, self-assembling peptide glycine-(phenylalanine)3GFFF-ac and the plasmin-cleavable GGKFKTGG were reacted with the cysteine-terminated CGGK(Fmoc/MTT) peptide through the MTT and Fmoc termini, respectively. The difunctional peptide was conjugated to polyethylene glycol diacrylate (PEGDA) with molecular weights (MW) ranging from 0.5 to 7.5 kDa, and the chain ends of the PEG-peptide conjugate were terminated with succinimide groups. After self-assembly in aqueous solution, BMP2 was grafted to the self-assembled, plasmin-cleavable PEG-based (P xSPCP) NPs for on-demand release. The NPs' stability in aqueous solution and that of the grafted BMP2 were strongly dependent on PEG MW. P2SPCP NPs showed high particle size stability, BMP2 grafting efficiency, grafted protein stability, and high extent of osteogenic differentiation of hMSCs. The localized and on-demand release of BMP2 from P xSPCP NPs coencapsulated with hMSCs in the linear polyethylene glycol- co-lactide acrylate patterned hydrogel with microchannels encapsulating hMSCs + ECFCs and VEGF-conjugated nanogels resulted in the highest extent of osteogenic and vasculogenic differentiation of the encapsulated cells compared to directly added BMP2/VEGF. The on-demand release of BMP2 from P xSPCP NPs not only enhances osteogenesis and vasculogenesis but also potentially reduces many undesired side effects of BMP2 therapy in bone regeneration.}, number={8}, journal={Biomacromolecules}, publisher={American Chemical Society (ACS)}, author={Kader, Safaa and Monavarian, Mehri and Barati, Danial and Moeinzadeh, Seyedsina and Makris, Thomas M. and Jabbari, Esmaiel}, year={2019}, pages={2973–2988} }
 @article{schlachter_daneshian_amaya_klapper_wybouw_borowski_leeuwen_grbic_grbic_makris_et al._2019, title={Structural and functional characterization of an intradiol ring-cleavage dioxygenase from the polyphagous spider mite herbivore Tetranychus urticae Koch}, volume={107}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85061438463&partnerID=MN8TOARS}, DOI={10.1016/j.ibmb.2018.12.001}, abstractNote={Genome analyses of the polyphagous spider mite herbivore Tetranychus urticae (two-spotted spider mite) revealed the presence of a set of 17 genes that code for secreted proteins belonging to the "intradiol dioxygenase-like" subgroup. Phylogenetic analyses indicate that this novel enzyme family has been acquired by horizontal gene transfer. In order to better understand the role of these proteins in T. urticae, we have structurally and functionally characterized one paralog (tetur07g02040). It was demonstrated that this protein is indeed an intradiol ring-cleavage dioxygenase, as the enzyme is able to cleave catechol between two hydroxyl-groups using atmospheric dioxygen. The enzyme was characterized functionally and structurally. The active site of the T. urticae enzyme contains an Fe3+ cofactor that is coordinated by two histidine and two tyrosine residues, an arrangement that is similar to those observed in bacterial homologs. However, the active site is significantly more solvent exposed than in bacterial proteins. Moreover, the mite enzyme is monomeric, while almost all structurally characterized bacterial homologs form oligomeric assemblies. Tetur07g02040 is not only the first spider mite dioxygenase that has been characterized at the molecular level, but is also the first structurally characterized intradiol ring-cleavage dioxygenase originating from a eukaryote.}, journal={Insect Biochemistry and Molecular Biology}, publisher={Elsevier BV}, author={Schlachter, Caleb R. and Daneshian, Leily and Amaya, Jose and Klapper, Vincent and Wybouw, Nicky and Borowski, Tomasz and Leeuwen, Thomas Van and Grbic, Vojislava and Grbic, Miodrag and Makris, Thomas M. and et al.}, year={2019}, pages={19–30} }
 @article{kaniusaite_goode_schittenhelm_makris_cryle_2019, title={The Diiron Monooxygenase CmlA from Chloramphenicol Biosynthesis Allows Reconstitution of β-Hydroxylation during Glycopeptide Antibiotic Biosynthesis}, volume={14}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85076512202&partnerID=MN8TOARS}, DOI={10.1021/acschembio.9b00862}, abstractNote={β-Hydroxylation plays an important role in the nonribosomal peptide biosynthesis of many important natural products, including bleomycin, chloramphenicol, and the glycopeptide antibiotics (GPAs). Various oxidative enzymes have been implicated in such a process, with the mechanism of incorporation varying from installation of hydroxyl groups in amino acid precursors prior to adenylation to direct amino acid oxidation during peptide assembly. In this work, we demonstrate the in vitro utility and scope of the unusual nonheme diiron monooxygenase CmlA from chloramphenicol biosynthesis for the β-hydroxylation of a diverse range of carrier protein bound substrates by adapting this enzyme as a non-native trans-acting enzyme within NRPS-mediated GPA biosynthesis. The results from our study show that CmlA has a broad substrate specificity for modified phenylalanine/tyrosine residues as substrates and can be used in a practical strategy to functionally cross complement compatible NRPS biosynthesis pathways in vitro.}, number={12}, journal={ACS Chemical Biology}, publisher={American Chemical Society (ACS)}, author={Kaniusaite, Milda and Goode, Robert J. A. and Schittenhelm, Ralf B. and Makris, Thomas M. and Cryle, Max J.}, year={2019}, pages={2932–2941} }
 @article{amaya_rutland_leschinsky_makris_2018, title={A Distal Loop Controls Product Release and Chemo- and Regioselectivity in Cytochrome P450 Decarboxylases}, volume={57}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85039039628&partnerID=MN8TOARS}, DOI={10.1021/acs.biochem.7b01065}, abstractNote={Cytochrome P450 OleT utilizes hydrogen peroxide (H2O2) to catalyze the decarboxylation or hydroxylation of fatty acid (FA) substrates. Both reactions are initiated through the abstraction of a substrate hydrogen atom by the high-valent iron-oxo intermediate known as Compound I. Here, we specifically probe the influence of substrate coordination on OleT reaction partitioning through the combined use of fluorescent and electron paramagnetic resonance (EPR)-active FA probes and mutagenesis of a structurally disordered F-G loop that is distal from the heme-iron active site. Both probes are efficiently metabolized by OleT and efficiently trigger the formation of Compound I. Transient fluorescence and EPR reveal a slow product release step, mediated by the F-G loop, that limits OleT turnover. A single-amino acid change or excision of the loop reveals that this region establishes critical interactions to anchor FA substrates in place. The stabilization afforded by the F-G loop is essential for regulating regiospecific C-H abstraction and allowing for efficient decarboxylation to occur. These results highlight a regulatory strategy whereby the fate of activated oxygen species can be controlled at distances far removed from the site of chemistry.}, number={3}, journal={Biochemistry}, publisher={American Chemical Society (ACS)}, author={Amaya, José A. and Rutland, Cooper D. and Leschinsky, Nicholas and Makris, Thomas M.}, year={2018}, pages={344–353} }
 @article{khivantsev_biancardi_fathizadeh_almalki_grant_tien_shakouri_blom_makris_regalbuto_et al._2018, title={Catalytic N−H Bond Activation and Breaking by a Well-Defined Co<sup>II</sup><inf>1</inf>O<inf>4</inf> Site of a Heterogeneous Catalyst}, volume={10}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85042260632&partnerID=MN8TOARS}, DOI={10.1002/cctc.201701268}, abstractNote={Abstract}, number={4}, journal={ChemCatChem}, author={Khivantsev, K. and Biancardi, A. and Fathizadeh, M. and Almalki, F. and Grant, J.L. and Tien, H.N. and Shakouri, A. and Blom, D.A. and Makris, T.M. and Regalbuto, J.R. and et al.}, year={2018}, pages={736–742} }
 @article{wise_hsieh_poplin_makris_2018, title={Dioxygen Activation by the Biofuel-Generating Cytochrome P450 OleT}, volume={8}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85053339142&partnerID=MN8TOARS}, DOI={10.1021/acscatal.8b02631}, abstractNote={OleT, a recently discovered member of the CYP152 family of cytochrome P450s, catalyzes a unique decarboxylation reaction, converting free fatty acids into 1-olefins and carbon dioxide using H2O2 as an oxidant. The C–C cleavage reaction proceeds through hydrogen atom abstraction by an iron(IV)-oxo intermediate known as Compound I. The capacity of the enzyme for generating important commodity chemicals and liquid biofuels has inspired a flurry of investigations seeking to maximize its biosynthetic potential. One common approach has sought to address the limitations imposed by the H2O2 cosubstrate, particularly for in vivo applications. Numerous reports have shown relatively efficient decarboxylation activity with various combinations of the enzyme with pyridine nucleotides, biological redox donors, and dioxygen, implicating a mechanism whereby OleT can generate Compound I via a canonical P450 O2 dependent reaction scheme. Here, we have applied transient kinetics, cryoradiolysis, and steady state turnover st...}, number={10}, journal={ACS Catalysis}, publisher={American Chemical Society (ACS)}, author={Wise, Courtney E. and Hsieh, Chun H. and Poplin, Nathan L. and Makris, Thomas M.}, year={2018}, pages={9342–9352} }
 @article{zhang_xu_makris_wang_2018, title={Enhanced Arylamine N -Oxygenase Activity of Polymer-Enzyme Assemblies by Facilitating Electron-Transferring Efficiency}, volume={19}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85043594000&partnerID=MN8TOARS}, DOI={10.1021/acs.biomac.7b01706}, abstractNote={A novel N-oxygenase-coated core-shell nanoparticle was generated through the coassembly of poly(4-vinylpyridine) (P4VP) and arylamine N-oxygenase CmlI. The resulting enzyme-hybridized particles, P4VP-CmlI, showed excellent catalytic activities on the oxidation of two arylamine substrates, i.e., p-aminophenol ( pAP) and p-aminobenzoic acid ( pABA), using a surrogate redox system or a peroxide shunt as co-oxidants. In comparison with the free enzyme, P4VP-CmlI particles exhibited a significantly enhanced catalytic efficiency when using pyridine nucleotide (NADH) and proper redox mediators. Products at different oxygenation stages were observed. On the contrary, the activity of the enzyme-containing nanoparticles was very similar to the free enzyme when using the peroxide shunt. The enhanced catalytic efficiency of the P4VP-CmlI assemblies is attributed to a more efficient electron delivery.}, number={3}, journal={Biomacromolecules}, publisher={American Chemical Society (ACS)}, author={Zhang, Libo and Xu, Yanmei and Makris, Thomas M. and Wang, Qian}, year={2018}, pages={918–925} }
 @article{mi?aczewska_kot_amaya_makris_zaj?c_korecki_chumakov_trzewik_k?dracka-krok_minor_et al._2018, title={On the Structure and Reaction Mechanism of Human Acireductone Dioxygenase}, volume={24}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85040864011&partnerID=MN8TOARS}, DOI={10.1002/chem.201704617}, abstractNote={Abstract}, number={20}, journal={Chemistry - A European Journal}, author={Mi?aczewska, A. and Kot, E. and Amaya, J.A. and Makris, T.M. and Zaj?c, M. and Korecki, J. and Chumakov, A. and Trzewik, B. and K?dracka-Krok, S. and Minor, W. and et al.}, year={2018}, pages={5225–5237} }
 @article{munro_mclean_grant_makris_2018, title={Structure and function of the cytochrome P450 peroxygenase enzymes}, volume={46}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85046902903&partnerID=MN8TOARS}, DOI={10.1042/BST20170218}, abstractNote={The cytochromes P450 (P450s or CYPs) constitute a large heme enzyme superfamily, members of which catalyze the oxidative transformation of a wide range of organic substrates, and whose functions are crucial to xenobiotic metabolism and steroid transformation in humans and other organisms. The P450 peroxygenases are a subgroup of the P450s that have evolved in microbes to catalyze the oxidative metabolism of fatty acids, using hydrogen peroxide as an oxidant rather than NAD(P)H-driven redox partner systems typical of the vast majority of other characterized P450 enzymes. Early members of the peroxygenase (CYP152) family were shown to catalyze hydroxylation at the α and β carbons of medium-to-long-chain fatty acids. However, more recent studies on other CYP152 family P450s revealed the ability to oxidatively decarboxylate fatty acids, generating terminal alkenes with potential applications as drop-in biofuels. Other research has revealed their capacity to decarboxylate and to desaturate hydroxylated fatty acids to form novel products. Structural data have revealed a common active site motif for the binding of the substrate carboxylate group in the peroxygenases, and mechanistic and transient kinetic analyses have demonstrated the formation of reactive iron-oxo species (compounds I and II) that are ultimately responsible for hydroxylation and decarboxylation of fatty acids, respectively. This short review will focus on the biochemical properties of the P450 peroxygenases and on their biotechnological applications with respect to production of volatile alkenes as biofuels, as well as other fine chemicals.}, number={1}, journal={Biochemical Society Transactions}, author={Munro, A.W. and McLean, K.J. and Grant, J.L. and Makris, T.M.}, year={2018}, pages={183–196} }
 @article{rahman_smith_amaya_makris_peryshkov_2017, title={Activation of C-H Bonds of Alkyl- and Arylnitriles by the TaCl<inf>5</inf>-PPh<inf>3</inf> Lewis Pair}, volume={56}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85030544373&partnerID=MN8TOARS}, DOI={10.1021/acs.inorgchem.7b01800}, abstractNote={A new pathway of activation of C-H bonds of alkyl- and arylnitriles by a cooperative action of TaCl5 and PPh3 under mild conditions is reported. Coordination of nitriles to the highly Lewis acidic Ta(V) center resulted in an activation of their aliphatic and aromatic C-H bonds, allowing nucleophilic attack and deprotonation by the relatively weak base PPh3. The propensity of Ta(V) to form multiple bonds to nitrogen-containing ligands is an important driving force of the reaction as it led to a sequence of bond rearrangements and the emergence of, in the case of benzonitrile, a zwitterionic enediimido complex of Ta(V) through C═C double bond formation between two activated nitrile fragments. These transformations highlight the special role of the high-valent transition metal halide in substrate activation and distinguish the reactivity of the TaCl5-PPh3 system from both non-metal- and late transition metal-based frustrated Lewis pairs.}, number={19}, journal={Inorganic Chemistry}, publisher={American Chemical Society (ACS)}, author={Rahman, Md. Mamdudur and Smith, Mark D. and Amaya, José A. and Makris, Thomas M. and Peryshkov, Dmitry V.}, year={2017}, pages={11798–11803} }
 @article{wise_grant_amaya_ratigan_hsieh_manley_makris_2017, title={Divergent mechanisms of iron-containing enzymes for hydrocarbon biosynthesis}, volume={22}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85006963683&partnerID=MN8TOARS}, DOI={10.1007/s00775-016-1425-0}, number={2-3}, journal={Journal of Biological Inorganic Chemistry}, author={Wise, C.E. and Grant, J.L. and Amaya, J.A. and Ratigan, S.C. and Hsieh, C.H. and Manley, O.M. and Makris, T.M.}, year={2017}, pages={221–235} }
 @article{dehaven_tokarski_korous_mentink‐vigier_makris_brugh_forbes_tol_bowers_shimizu_2017, title={Persistent Radicals of Self-assembled Benzophenone bis-Urea Macrocycles: Characterization and Application as a Polarizing Agent for Solid-state DNP MAS Spectroscopy}, volume={23}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85020882423&partnerID=MN8TOARS}, DOI={10.1002/chem.201701705}, abstractNote={Abstract}, number={34}, journal={Chemistry - A European Journal}, author={DeHaven, Baillie A. and Tokarski, John T., III and Korous, Arthur A. and Mentink‐Vigier, Frederic and Makris, Thomas M. and Brugh, Alexander M. and Forbes, Malcolm D. E. and Tol, Johan and Bowers, Clifford R. and Shimizu, Linda S.}, year={2017}, pages={8315–8319} }
 @article{wise_makris_2017, title={Recruitment and Regulation of the Non-ribosomal Peptide Synthetase Modifying Cytochrome P450 Involved in Nikkomycin Biosynthesis}, volume={12}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85019551265&partnerID=MN8TOARS}, DOI={10.1021/acschembio.7b00081}, abstractNote={The β-hydroxylation of l-histidine is the first step in the biosynthesis of the imidazolone base of the antifungal drug nikkomycin. The cytochrome P450 (NikQ) hydroxylates the amino acid while it is appended via a phosphopantetheine linker to the non-ribosomal peptide synthetase (NRPS) NikP1. The latter enzyme is comprised of an MbtH and single adenylation and thiolation domains, a minimal composition that allows for detailed binding and kinetics studies using an intact and homogeneous NRPS substrate. Electron paramagnetic resonance studies confirm that a stable complex is formed with NikQ and NikP1 when the amino acid is tethered. Size exclusion chromatography is used to further refine the principal components that are required for this interaction. NikQ binds NikP1 in the fully charged state, but binding also occurs when NikP1 is lacking both the phosphopantetheine arm and appended amino acid. This demonstrates that the interaction is mainly guided by presentation of the thiolation domain interface, rather than the attached amino acid. Electrochemistry and transient kinetics have been used to probe the influence of l-His-NikP1 binding on catalysis by NikQ. Unlike many P450s, the binding of substrate fails to induce significant changes on the redox potential and autoxidation properties of NikQ and slows down the binding of dioxygen to the ferrous enzyme to initiate catalysis. Collectively, these studies demonstrate a complex interplay between the NRPS maturation process and the recruitment and regulation of an auxiliary tailoring enzyme required for natural product biosynthesis.}, number={5}, journal={ACS Chemical Biology}, publisher={American Chemical Society (ACS)}, author={Wise, Courtney E. and Makris, Thomas M.}, year={2017}, pages={1316–1326} }
 @article{hsieh_huang_amaya_rutland_keys_groves_austin_makris_2017, title={The Enigmatic P450 Decarboxylase OleT Is Capable of, but Evolved to Frustrate, Oxygen Rebound Chemistry}, volume={56}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85021982634&partnerID=MN8TOARS}, DOI={10.1021/acs.biochem.7b00338}, abstractNote={OleT is a cytochrome P450 enzyme that catalyzes the removal of carbon dioxide from variable chain length fatty acids to form 1-alkenes. In this work, we examine the binding and metabolic profile of OleT with shorter chain length (n ≤ 12) fatty acids that can form liquid transportation fuels. Transient kinetics and product analyses confirm that OleT capably activates hydrogen peroxide with shorter substrates to form the high-valent intermediate Compound I and largely performs C-C bond scission. However, the enzyme also produces fatty alcohol side products using the high-valent iron oxo chemistry commonly associated with insertion of oxygen into hydrocarbons. When presented with a short chain fatty acid that can initiate the formation of Compound I, OleT oxidizes the diagnostic probe molecules norcarane and methylcyclopropane in a manner that is reminiscent of reactions of many CYP hydroxylases with radical clock substrates. These data are consistent with a decarboxylation mechanism in which Compound I abstracts a substrate hydrogen atom in the initial step. Positioning of the incipient substrate radical is a crucial element in controlling the efficiency of activated OH rebound.}, number={26}, journal={Biochemistry}, publisher={American Chemical Society (ACS)}, author={Hsieh, Chun H. and Huang, Xiongyi and Amaya, José A. and Rutland, Cooper D. and Keys, Carson L. and Groves, John T. and Austin, Rachel N. and Makris, Thomas M.}, year={2017}, pages={3347–3357} }
 @article{grant_mitchell_makris_2016, title={Catalytic strategy for carbon-carbon bond scission by the cytochrome p450 olet}, volume={113}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84986285597&partnerID=MN8TOARS}, DOI={10.1073/pnas.1606294113}, abstractNote={Significance}, number={36}, journal={Proceedings of the National Academy of Sciences of the United States of America}, author={Grant, J.L. and Mitchell, M.E. and Makris, T.M.}, year={2016}, pages={10049–10054} }
 @article{hsieh_makris_2016, title={Expanding the substrate scope and reactivity of cytochrome P450 OleT}, volume={476}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84971671300&partnerID=MN8TOARS}, DOI={10.1016/j.bbrc.2016.05.145}, abstractNote={The efficient hydrogen peroxide-dependent hydroxylation and epoxidation of hydrocarbons is catalysed by a P450 fatty acid decarboxylase (OleT) active-site variant. The introduction of an acidic functionality in the protein framework circumvents the necessity for a carboxylate that is typically provided by the substrate for efficient H2O2 heterolysis. Spectroscopic and turnover studies show that the mutation eliminates the binding and metabolism of prototypical fatty acid substrates, but permits the oxidation of a broad range of inert hydrocarbon substrates.}, number={4}, journal={Biochemical and Biophysical Research Communications}, publisher={Elsevier BV}, author={Hsieh, Chun H. and Makris, Thomas M.}, year={2016}, pages={462–466} }
 @article{amaya_rutland_makris_2016, title={Mixed regiospecificity compromises alkene synthesis by a cytochrome P450 peroxygenase from Methylobacterium populi}, volume={158}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84959490870&partnerID=MN8TOARS}, DOI={10.1016/j.jinorgbio.2016.02.031}, abstractNote={Intensive interest has focused on enzymes that are capable of synthesizing hydrocarbons, alkenes and alkanes, for sustainable fuel production. A recently described cytochrome P450 (OleTJE) from the CYP152 family catalyzes an unusual carbon-carbon scission reaction, transforming Cn fatty acids to Cn-1 1-alkenes. Here, we show that a second CYP152, CYP-MP from Methylobacterium populi ATCC BAA 705, also catalyzes oxidative substrate decarboxylation. Alkene production is accompanied with the production of fatty alcohol products, underscoring the mechanistic similarity of the decarboxylation reaction with canonical P450 monooxygenation chemistry. The branchpoint of these two chemistries, and regiospecificity of oxidation products, is strongly chain length dependent, suggesting an importance of substrate coordination for regulating alkene production.}, journal={Journal of Inorganic Biochemistry}, publisher={Elsevier BV}, author={Amaya, Jose A. and Rutland, Cooper D. and Makris, Thomas M.}, year={2016}, pages={11–16} }
 @article{makris_vu_meier_komor_rivard_münck_que_lipscomb_2015, title={An unusual peroxo intermediate of the arylamine oxygenase of the chloramphenicol biosynthetic pathway}, volume={137}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84922344851&partnerID=MN8TOARS}, DOI={10.1021/ja511649n}, abstractNote={Streptomyces venezuelae CmlI catalyzes the six-electron oxygenation of the arylamine precursor of chloramphenicol in a nonribosomal peptide synthetase (NRPS)-based pathway to yield the nitroaryl group of the antibiotic. Optical, EPR, and Mössbauer studies show that the enzyme contains a nonheme dinuclear iron cluster. Addition of O(2) to the diferrous state of the cluster results in an exceptionally long-lived intermediate (t(1/2) = 3 h at 4 °C) that is assigned as a peroxodiferric species (CmlI-peroxo) based upon the observation of an (18)O(2)-sensitive resonance Raman (rR) vibration. CmlI-peroxo is spectroscopically distinct from the well characterized and commonly observed cis-μ-1,2-peroxo (μ-η(1):η(1)) intermediates of nonheme diiron enzymes. Specifically, it exhibits a blue-shifted broad absorption band around 500 nm and a rR spectrum with a ν(O-O) that is at least 60 cm(-1) lower in energy. Mössbauer studies of the peroxo state reveal a diferric cluster having iron sites with small quadrupole splittings and distinct isomer shifts (0.54 and 0.62 mm/s). Taken together, the spectroscopic comparisons clearly indicate that CmlI-peroxo does not have a μ-η(1):η(1)-peroxo ligand; we propose that a μ-η(1):η(2)-peroxo ligand accounts for its distinct spectroscopic properties. CmlI-peroxo reacts with a range of arylamine substrates by an apparent second-order process, indicating that CmlI-peroxo is the reactive species of the catalytic cycle. Efficient production of chloramphenicol from the free arylamine precursor suggests that CmlI catalyzes the ultimate step in the biosynthetic pathway and that the precursor is not bound to the NRPS during this step.}, number={4}, journal={Journal of the American Chemical Society}, publisher={American Chemical Society (ACS)}, author={Makris, Thomas M. and Vu, Van V. and Meier, Katlyn K. and Komor, Anna J. and Rivard, Brent S. and Münck, Eckard and Que, Lawrence and Lipscomb, John D.}, year={2015}, pages={1608–1617} }
 @article{grant_hsieh_makris_2015, title={Decarboxylation of fatty acids to terminal alkenes by cytochrome P450 compound i}, volume={137}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84928485740&partnerID=MN8TOARS}, DOI={10.1021/jacs.5b01965}, abstractNote={OleT(JE), a cytochrome P450, catalyzes the conversion of fatty acids to terminal alkenes using hydrogen peroxide as a cosubstrate. Analytical studies with an eicosanoic acid substrate show that the enzyme predominantly generates nonadecene and that carbon dioxide is the one carbon coproduct of the reaction. The addition of hydrogen peroxide to a deuterated substrate-enzyme (E-S) complex results in the transient formation of an iron(IV) oxo π cation radical (Compound I) intermediate which is spectroscopically indistinguishable from those that perform oxygen insertion chemistries. A kinetic isotope effect for Compound I decay suggests that it abstracts a substrate hydrogen atom to initiate fatty acid decarboxylation. Together, these results indicate that the initial mechanism for alkene formation, which does not result from oxygen rebound, is similar to that widely suggested for P450 monooxygenation reactions.}, number={15}, journal={Journal of the American Chemical Society}, publisher={American Chemical Society (ACS)}, author={Grant, Job L. and Hsieh, Chun H. and Makris, Thomas M.}, year={2015}, pages={4940–4943} }
 @article{abeysinghe_gerke_morrison_hsieh_smith_pöttgen_makris_loye_2015, title={Synthesis, characterization, and properties of reduced europium molybdates and tungstates}, volume={229}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84930948194&partnerID=MN8TOARS}, DOI={10.1016/j.jssc.2015.05.014}, abstractNote={Single crystals of K0.094Eu0.906MoO4, K0.097Eu0.903WO4, EuWO4, and EuMoO4 were grown from molten chloride fluxes contained in vacuum-sealed fused silica and structurally characterized via single crystal X-ray diffraction. The in situ reduction of Eu3+ to Eu2+ was carried out using Mo, W, and Zn as metal reducing agents. All four compounds crystallize in the tetragonal space group of I41/a and adopt the scheelite (CaWO4) structure type. The magnetic susceptibility of the reported compounds shows paramagnetic behavior down to 2 K. 151Eu Mössbauer spectroscopy was used to analyze the relative Eu2+ and Eu3+ content of the samples. All the compounds were further characterized by EPR, and UV-vis spectroscopy.}, journal={Journal of Solid State Chemistry}, publisher={Elsevier BV}, author={Abeysinghe, Dileka and Gerke, Birgit and Morrison, Gregory and Hsieh, Chun H. and Smith, Mark D. and Pöttgen, Rainer and Makris, Thomas M. and Loye, Hans-Conrad}, year={2015}, month={Sep}, pages={173–180} }
 @article{catalase (kata) plays a role in protection against anaerobic nitric oxide in pseudomonas aeruginosa_2014, volume={9}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84899754373&partnerID=MN8TOARS}, DOI={10.1371/journal.pone.0091813}, abstractNote={Pseudomonas aeruginosa (PA) is a common bacterial pathogen, responsible for a high incidence of nosocomial and respiratory infections. KatA is the major catalase of PA that detoxifies hydrogen peroxide (H2O2), a reactive oxygen intermediate generated during aerobic respiration. Paradoxically, PA displays elevated KatA activity under anaerobic growth conditions where the substrate of KatA, H2O2, is not produced. The aim of the present study is to elucidate the mechanism underlying this phenomenon and define the role of KatA in PA during anaerobiosis using genetic, biochemical and biophysical approaches. We demonstrated that anaerobic wild-type PAO1 cells yielded higher levels of katA transcription and expression than aerobic cells, whereas a nitrite reductase mutant ΔnirS produced ∼50% the KatA activity of PAO1, suggesting that a basal NO level was required for the increased KatA activity. We also found that transcription of the katA gene was controlled, in part, by the master anaerobic regulator, ANR. A ΔkatA mutant and a mucoid mucA22 ΔkatA bacteria demonstrated increased sensitivity to acidified nitrite (an NO generator) in anaerobic planktonic and biofilm cultures. EPR spectra of anaerobic bacteria showed that levels of dinitrosyl iron complexes (DNIC), indicators of NO stress, were increased significantly in the ΔkatA mutant, and dramatically in a ΔnorCB mutant compared to basal levels of DNIC in PAO1 and ΔnirS mutant. Expression of KatA dramatically reduced the DNIC levels in ΔnorCB mutant. We further revealed direct NO-KatA interactions in vitro using EPR, optical spectroscopy and X-ray crystallography. KatA has a 5-coordinate high spin ferric heme that binds NO without prior reduction of the heme iron (K d ∼6 μM). Collectively, we conclude that KatA is expressed to protect PA against NO generated during anaerobic respiration. We proposed that such protective effects of KatA may involve buffering of free NO when potentially toxic concentrations of NO are approached.}, number={3}, journal={PLoS ONE}, year={2014} }
 @article{aukema_makris_stoian_richman_münck_lipscomb_wackett_2013, title={Cyanobacterial aldehyde deformylase oxygenation of aldehydes yields n - 1 aldehydes and alcohols in addition to alkanes}, volume={3}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84885366130&partnerID=MN8TOARS}, DOI={10.1021/cs400484m}, abstractNote={Aldehyde-deformylating oxygenase (ADO) catalyzes O2-dependent release of the terminal carbon of a biological substrate, octadecanal, to yield formate and heptadecane in a reaction that requires external reducing equivalents. We show here that ADO also catalyzes incorporation of an oxygen atom from O2 into the alkane product to yield alcohol and aldehyde products. Oxygenation of the alkane product is much more pronounced with C9-10 aldehyde substrates, so that use of nonanal as the substrate yields similar amounts of octane, octanal, and octanol products. When using doubly-labeled [1,2-13C]-octanal as the substrate, the heptane, heptanal and heptanol products each contained a single 13C-label in the C-1 carbons atoms. The only one-carbon product identified was formate. [18O]-O2 incorporation studies demonstrated formation of [18O]-alcohol product, but rapid solvent exchange prevented similar determination for the aldehyde product. Addition of [1-13C]-nonanol with decanal as the substrate at the outset of the reaction resulted in formation of [1-13C]-nonanal. No 13C-product was formed in the absence of decanal. ADO contains an oxygen-bridged dinuclear iron cluster. The observation of alcohol and aldehyde products derived from the initially formed alkane product suggests a reactive species similar to that formed by methane monooxygenase (MMO) and other members of the bacterial multicomponent monooxygenase family. Accordingly, characterization by EPR and Mössbauer spectroscopies shows that the electronic structure of the ADO cluster is similar, but not identical, to that of MMO hydroxylase component. In particular, the two irons of ADO reside in nearly identical environments in both the oxidized and fully reduced states, whereas those of MMOH show distinct differences. These favorable characteristics of the iron sites allow a comprehensive determination of the spin Hamiltonian parameters describing the electronic state of the diferrous cluster for the first time for any biological system. The nature of the diiron cluster and the newly recognized products from ADO catalysis hold implications for the mechanism of C-C bond cleavage.}, number={10}, journal={ACS Catalysis}, author={Aukema, K.G. and Makris, T.M. and Stoian, S.A. and Richman, J.E. and Münck, E. and Lipscomb, J.D. and Wackett, L.P.}, year={2013}, pages={2228–2238} }
 @article{makris_knoot_wilmot_lipscomb_2013, title={Structure of a dinuclear iron cluster-containing β-hydroxylase active in antibiotic biosynthesis}, volume={52}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84884898038&partnerID=MN8TOARS}, DOI={10.1021/bi400845b}, abstractNote={A family of dinuclear iron cluster-containing oxygenases that catalyze β-hydroxylation tailoring reactions in natural product biosynthesis by nonribosomal peptide synthetase (NRPS) systems was recently described [Makris, T. M., Chakrabarti, M., Münck, E., and Lipscomb, J. D. (2010) Proc. Natl. Acad. Sci. U.S.A. 107, 15391-15396]. Here, the 2.17 Å X-ray crystal structure of the archetypal enzyme from the family, CmlA, is reported. CmlA catalyzes β-hydroxylation of l-p-aminophenylalanine during chloramphenicol biosynthesis. The fold of the N-terminal domain of CmlA is unlike any previously reported, but the C-terminal domain has the αββα fold of the metallo-β-lactamase (MBL) superfamily. The diiron cluster bound in the C-terminal domain is coordinated by an acetate, three His residues, two Asp residues, one Glu residue, and a bridging oxo moiety. One of the Asp ligands forms an unusual monodentate bridge. No other oxygen-activating diiron enzyme utilizes this ligation or the MBL protein fold. The N-terminal domain facilitates dimerization, but using computational docking and a sequence-based structural comparison to homologues, we hypothesize that it likely serves additional roles in NRPS recognition and the regulation of O2 activation.}, number={38}, journal={Biochemistry}, author={Makris, T.M. and Knoot, C.J. and Wilmot, C.M. and Lipscomb, J.D.}, year={2013}, pages={6662–6671} }
 @article{thompson_salahudeen_chollangi_ruiz_brautigam_makris_lipscomb_tomchick_bruick_2012, title={Structural and molecular characterization of iron-sensing hemerythrin-like domain within F-box and leucine-rich repeat protein 5 (FBXL5)}, volume={287}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84863393257&partnerID=MN8TOARS}, DOI={10.1074/jbc.M111.308684}, abstractNote={Background: FBXL5 is required for proper regulation of cellular iron homeostasis. Results: FBXL5 contains a structurally characterized hemerythrin-like domain. Conclusion: The atypical features of the hemerythrin-like domain facilitate its role as a metabolic sensor. Significance: FBXL5 is the only identified mammalian protein containing a hemerythrin-like domain. Resolution of the structure of the domain provides mechanistic insights into its iron and oxygen responsiveness. Mammalian cells maintain iron homeostasis by sensing changes in bioavailable iron levels and promoting adaptive responses. FBXL5 is a subunit of an E3 ubiquitin ligase complex that mediates the stability of iron regulatory protein 2, an important posttranscriptional regulator of several genes involved in iron metabolism. The stability of FBXL5 is regulated in an iron- and oxygen-responsive manner, contingent upon the presence of its N-terminal domain. Here we present the atomic structure of the FBXL5 N terminus, a hemerythrin-like α-helical bundle fold not previously observed in mammalian proteins. The core of this domain employs an unusual assortment of amino acids necessary for the assembly and sensing properties of its diiron center. These regulatory features govern the accessibility of a mapped sequence required for proteasomal degradation of FBXL5. Detailed molecular and structural characterization of the ligand-responsive hemerythrin domain provides insights into the mechanisms by which FBXL5 serves as a unique mammalian metabolic sensor.}, number={10}, journal={Journal of Biological Chemistry}, author={Thompson, J.W. and Salahudeen, A.A. and Chollangi, S. and Ruiz, J.C. and Brautigam, C.A. and Makris, T.M. and Lipscomb, J.D. and Tomchick, D.R. and Bruick, R.K.}, year={2012}, pages={7357–7365} }
 @article{active-site structure of a β-hydroxylase in antibiotic biosynthesis_2011, volume={133}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-79955687624&partnerID=MN8TOARS}, DOI={10.1021/ja201822v}, abstractNote={X-ray absorption and resonance Raman spectroscopies show that CmlA, the β-hydroxylase of the chloramphenicol biosynthetic pathway, contains a (μ-oxo)-(μ-1,3-carboxylato)diiron(III) cluster with 6-coordinate iron centers and 3 - 4 His ligands. This active site is found within a unique β-lactamase fold and is distinct from those of soluble methane monooxygenase and related enzymes that utilize a highly conserved diiron cluster with a 2-His-4-carboxylate ligand set within a 4-helix bundle motif. These structural differences may have an impact on the nature of the activated oxygen species of the reaction cycle.}, number={18}, journal={Journal of the American Chemical Society}, year={2011}, pages={6938–6941} }
 @article{knoot_makris_lipscomb_2011, title={Dinuclear Iron Cluster-Containing Oxygenase CmlA}, DOI={10.1002/9781119951438.eibc2329}, abstractNote={Abstract}, journal={Encyclopedia of Inorganic and Bioinorganic Chemistry}, author={Knoot, Cory J and Makris, Thomas M and Lipscomb, John D}, year={2011} }
 @article{makris_chakrabarti_münck_lipscomb_2010, title={A family of diiron monooxygenases catalyzing amino acid beta-hydroxylation in antibiotic biosynthesis}, volume={107}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-77957256569&partnerID=MN8TOARS}, DOI={10.1073/pnas.1007953107}, abstractNote={
            The biosynthesis of chloramphenicol requires a β-hydroxylation tailoring reaction of the precursor L-p-aminophenylalanine (L-PAPA). Here, it is shown that this reaction is catalyzed by the enzyme CmlA from an operon containing the genes for biosynthesis of L-PAPA and the nonribosomal peptide synthetase CmlP. EPR, Mössbauer, and optical spectroscopies reveal that CmlA contains an oxo-bridged dinuclear iron cluster, a metal center not previously associated with nonribosomal peptide synthetase chemistry. Single-turnover kinetic studies indicate that CmlA is functional in the diferrous state and that its substrate is L-PAPA covalently bound to CmlP. Analytical studies show that the product is hydroxylated L-PAPA and that O
            
              2
            
            is the oxygen source, demonstrating a monooxygenase reaction. The gene sequence of CmlA shows that it utilizes a lactamase fold, suggesting that the diiron cluster is in a protein environment not previously known to effect monooxygenase reactions. Notably, CmlA homologs are widely distributed in natural product biosynthetic pathways, including a variety of pharmaceutically important beta-hydroxylated antibiotics and cytostatics.
          }, number={35}, journal={Proceedings of the National Academy of Sciences of the United States of America}, author={Makris, T.M. and Chakrabarti, M. and Münck, E. and Lipscomb, J.D.}, year={2010}, pages={15391–15396} }
 @article{denisov_mak_makris_sligar_kincaid_2008, title={Resonance Raman characterization of the peroxo and hydroperoxo intermediates in cytochrome P450}, volume={112}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-58149173944&partnerID=MN8TOARS}, DOI={10.1021/jp8017875}, abstractNote={Resonance Raman (RR) studies of intermediates generated by cryoreduction of the oxyferrous complex of the D251N mutant of cytochrome P450(cam) (CYP101) are reported. Owing to the fact that proton delivery to the active site is hindered in this mutant, the unprotonated peroxo-ferric intermediate is observed as the primary species after radiolytic reduction of the oxy-complex in frozen solutions at 77 K. In as much as previous EPR and ENDOR studies have shown that annealing of this species to approximately 180 K results in protonation of the distal oxygen atom to form the hydroperoxo intermediate, this system has been exploited to permit direct RR interrogation of the changes in the Fe-O and O-O bonds caused by the reduction and subsequent protonation. Our results show that the nu(O-O) mode decreases from a superoxo-like frequency near approximately 1130 cm(-1) to 792 cm(-1) upon reduction. The latter frequency, as well as its lack of sensitivity to H/D exchange, is consistent with heme-bound peroxide formulation. This species also exhibits a nu(Fe-O) mode, the 553 cm(-1) frequency of which is higher than that observed for the nonreduced oxy P450 precursor (537 cm(-1)), implying a strengthened Fe-O linkage upon reduction. Upon subsequent protonation, the resulting Fe-O-OH fragment exhibits a lowered nu(O-O) mode at 774 cm(-1), whereas the nu(Fe-O) increases to 564 cm(-1). Both modes exhibit a downshift upon H/D exchange, as expected for a hydroperoxo-ferric formulation. These experimental RR data are compared with those previously acquired for the wild-type protein, and the shifts observed upon reduction and subsequent protonation are discussed with reference to theoretical predictions.}, number={50}, journal={Journal of Physical Chemistry A}, author={Denisov, I.G. and Mak, P.J. and Makris, T.M. and Sligar, S.G. and Kincaid, J.R.}, year={2008}, pages={13172–13179} }
 @article{makris_von koenig_schlichting_sligar_2007, title={Alteration of P450 distal pocket solvent leads to impaired proton delivery and changes in heme geometry}, volume={46}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-37049036930&partnerID=MN8TOARS}, DOI={10.1021/bi7013695}, abstractNote={Distal pocket water molecules have been widely implicated in the delivery of protons required in O-O bond heterolysis in the P450 reaction cycle. Targeted dehydration of the cytochrome P450cam (CYP101) distal pocket through mutagenesis of a distal pocket glycine to either valine or threonine results in the alteration of spin state equilibria, and has dramatic consequences on the catalytic rate, coupling efficiency, and kinetic solvent isotope effect parameters, highlighting an important role of the active-site hydration level on P450 catalysis. Cryoradiolysis of the mutant CYP101 oxyferrous complexes further indicates a specific perturbation of proton-transfer events required for the transformation of ferric-peroxo to ferric-hydroperoxo states. Finally, crystallography of the 248Val and 248Thr mutants in both the ferric camphor bound resting state and ferric-cyano adducts shows both the alteration of hydrogen-bonding networks and the alteration of heme geometry parameters. Taken together, these results indicate that the distal pocket microenvironment governs the transformation of reactive heme-oxygen intermediates in P450 cytochromes.}, number={49}, journal={Biochemistry}, author={Makris, T.M. and Von Koenig, K. and Schlichting, I. and Sligar, S.G.}, year={2007}, pages={14129–14140} }
 @article{mak_denisov_victoria_makris_deng_sligar_kincaid_2007, title={Resonance Raman detection of the hydroperoxo intermediate in the cytochrome P450 enzymatic cycle}, volume={129}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-34249044773&partnerID=MN8TOARS}, DOI={10.1021/ja071426h}, abstractNote={The resonance Raman spectra of the hydroperoxo complex of camphor-bound CYP101 have been obtained by cryoradiolytic reduction of the oxygenated ferrous form that had been rapidly frozen in water/glycerol frozen solution; EPR spectroscopy was employed to confirm the identity of the trapped intermediate. The ν(O−O) mode, appearing at 799 cm-1, is observed for the first time in a peroxo-heme adduct. It is assigned unambiguously by employing isotopomeric mixtures of oxygen gas containing 50% 16O18O, confirming the presence of an intact O−O fragment. The ν(Fe−O) mode is observed at 559 cm-1 (H2O). Furthermore, both modes shift down by 3 cm-1, documenting the formulation as a hydroperoxo complex, in agreement with EPR data.}, number={20}, journal={Journal of the American Chemical Society}, author={Mak, P.J. and Denisov, I.G. and Victoria, D. and Makris, T.M. and Deng, T. and Sligar, S.G. and Kincaid, J.R.}, year={2007}, pages={6382–6383} }
 @article{newcomb_zhang_chandrasena_halgrimson_horner_makris_sligar_2006, title={Cytochrome P450 compound I}, volume={128}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33646045616&partnerID=MN8TOARS}, DOI={10.1021/ja060048y}, abstractNote={Cytochrome P450 enzymes (P450s) comprise a large class of enzymes that effect numerous oxidations in nature. The active oxidants in P450s are thought to be iron(IV)-oxo porphyrin radical cations termed Compounds I, and these intermediates have been sought since the discovery of P450s 40 years ago. We report formation of the Compound I derivative of a P450 enzyme by laser flash photolysis oxidation of the corresponding Compound II species, an iron(IV)-oxo neutral porphyrin intermediate. The Compound II derivative in turn was produced by oxidation of the P450 with peroxynitrite, which effected a net one-electron, oxo-transfer reaction to the iron(III) atom of the resting enzyme. For the P450 studied in this work, CYP119 from the thermophile Sulfolobus solfactaricus, the P450 Compound II derivative was stable for seconds at ambient temperature, and the Compound I transient decayed with a lifetime of ca. 200 ms.}, number={14}, journal={Journal of the American Chemical Society}, author={Newcomb, M. and Zhang, R. and Chandrasena, R.E.P. and Halgrimson, J.A. and Horner, J.H. and Makris, T.M. and Sligar, S.G.}, year={2006}, pages={4580–4581} }
 @article{makris_koenig_schlichting_sligar_2006, title={The status of high-valent metal oxo complexes in the P450 cytochromes}, volume={100}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33645892004&partnerID=MN8TOARS}, DOI={10.1016/j.jinorgbio.2006.01.025}, abstractNote={The oxidative prowess of the P450 cytochromes in physiological reactions is attributed to the production of a high-valent iron-oxo complex, or Compound I intermediate, in the reaction cycle. Despite many years of study, however, the full electronic description of this fleeting intermediate still remains an active area of study. In this manuscript, the current status of the isolation and characterization of the P450 oxo-Fe(IV) is examined and compared to analogous states in related heme enzymes. In addition, the utilization of cofactor exchange to stabilize high-valent oxo-states in the P450 is addressed. Structural and spectroscopic studies on manganese reconstituted P450, and its corresponding oxo-complex, are presented.}, number={4}, journal={Journal of Inorganic Biochemistry}, author={Makris, T.M. and Koenig, K.v. and Schlichting, I. and Sligar, S.G.}, year={2006}, pages={507–518} }
 @article{ke_baudry_makris_schuler_sligar_2005, title={A retinoic acid binding cytochrome P450: CYP120A1 from Synechocystis sp. PCC 6803}, volume={436}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-14744294199&partnerID=MN8TOARS}, DOI={10.1016/j.abb.2005.01.011}, abstractNote={At least 35 cytochrome P450 (P450, CYP) or cytochrome P450-like genes have been identified in 10 cyanobacterial genomes yet none have been functionally characterized. CYP110 and CYP120 represent the two largest cyanobacterial P450 families with 16 and four members, respectively, identified to date. The Synechocystis sp. PCC 6803 CYP120A1 protein sequence shares high degrees of conservation with CYP120A2 from Trichodesmium erythraeum IMS101 and CYP120B1 and CYP120C1 from Nostoc punctiforme PCC 73102. In this communication, we report the cloning, expression, purification, and characterization of CYP120A1 from Synechocystis. Homology modeling predictions of the three-dimensional structure of CYP120A1 coupled with in silico screening for potential substrates and experimental spectroscopic analyses have identified retinoic acid as a compound binding with high affinity to this P450’s catalytic site. These characterizations of Synechocystis CYP120A1 lay the initial foundations for understanding the basic role of cytochrome P450s in cyanobacteria and related organisms.}, number={1}, journal={Archives of Biochemistry and Biophysics}, author={Ke, N. and Baudry, J. and Makris, T.M. and Schuler, M.A. and Sligar, S.G.}, year={2005}, pages={110–120} }
 @book{makris_denisov_schlichting_sligar_2005, title={Activation of molecular oxygen by cytochrome P450}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84892305135&partnerID=MN8TOARS}, DOI={10.1007/0-387-27447-2_5}, journal={Cytochrome P450: Structure, Mechanism, and Biochemistry: Third edition}, author={Makris, T.M. and Denisov, I. and Schlichting, I. and Sligar, S.G.}, year={2005}, pages={149–182} }
 @article{denisov_makris_sligar_schlichting_2005, title={Structure and chemistry of cytochrome P450}, volume={105}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-21844434930&partnerID=MN8TOARS}, DOI={10.1021/cr0307143}, abstractNote={Two decades have passed since the discovery in liver microsomes of a haemprotein that forms a reduced-CO complex with the absorptive maximum of the Soret at 450 nm (Klingenberg, 1958; Garfinkel, 1958) and the identification of this protein as a new cytochrome: pigment cytochrome, P-450 (Omura and Sato, 1962, 1964a). In the intervening years, the study of cytochrome P-450 dependent monoxygenases has expanded exponentially. From the first crude attempts to solubilise a P-450 (Omura and Sato, 1963, 1964b) to the determination of the primary, secondary, and tertiary structure of cytochrome P-450cam by amino acid sequencing (Haniu et al., 1982a,b) and x-ray crystallography (Poulos et al., 1984) our understanding of this unique family of proteins has been advancing on all fronts. Since, perhaps, the greatest understanding of the structure and mechanism of P-450s has come from concentrated study of P-450cam of the Pseudomonas putida camphor-5-exo-hydroxylase, this review will concentrate on findings with P-450cam; attention will be drawn to parallel and contrasting examples from other P-450s as appropriate.}, number={6}, journal={Chemical Reviews}, author={Denisov, I.G. and Makris, T.M. and Sligar, S.G. and Schlichting, I.}, year={2005}, pages={2253–2277} }
 @article{sono_perera_jin_makris_sligar_bryson_dawson_2005, title={The influence of substrate on the spectral properties of oxyferrous wild-type and T252A cytochrome P450-CAM}, volume={436}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-14744296960&partnerID=MN8TOARS}, DOI={10.1016/j.abb.2004.12.026}, abstractNote={To probe whether the nature of the substrate can directly influence the spectral properties of oxyferrous cytochrome P450-CAM, the complex has been investigated in the absence and in the presence of the natural substrate (1R)-camphor (camphor) and of several camphor analogs. The oxyferrous complex of T252A P450-CAM, a mutant lacking the hydroxyl group that forms a hydrogen bond to the heme iron-coordinated dioxygen, has also been studied to gauge the influence of this hydrogen bond. UV–visible absorption and magnetic circular dichroism (MCD) spectra of these oxyferrous adducts prepared and stabilized at −40 °C in 60% (v/v) ethylene glycol are generally similar, exhibiting absorption bands at ∼355, ∼420, ∼554, and ∼585 nm (shoulder) and a characteristic MCD trough at ∼585 nm. The MCD spectrum of camphor-bound oxyferrous P450-CAM is similar to that of the substrate-free oxyferrous enzyme, but the spectrum of the oxyferrous enzyme differs detectably in the presence of substrate analogs. The spectra of the oxyferrous T252A mutant and wild-type enzyme are overall similar except for Soret band position blue shifts by 2–6 nm for the mutant. 5-Methylenylcamphor (epoxidation substrate) appears to have an anomalous binding mode for the mutant compared with that for the wild-type enzyme. The present results indicate that the structures of the camphor analogs can sensitively influence the physical (spectroscopic) properties of the P450 dioxygen complex and could also affect its reactivity. The ability of substrate to modulate the reactivity of P450 intermediates could be a relevant factor in explaining the remarkable diversity of reactions catalyzed by the enzyme.}, number={1}, journal={Archives of Biochemistry and Biophysics}, author={Sono, M. and Perera, R. and Jin, S. and Makris, T.M. and Sligar, S.G. and Bryson, T.A. and Dawson, J.H.}, year={2005}, pages={40–49} }
 @article{sligar_makris_denisov_2005, title={Thirty years of microbial P450 monooxygenase research: Peroxo-heme intermediates - The central bus station in heme oxygenase catalysis}, volume={338}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-27544483600&partnerID=MN8TOARS}, DOI={10.1016/j.bbrc.2005.08.094}, abstractNote={Oxygen has always been recognized as an essential element of many life forms, initially through its role as a terminal electron acceptor for the energy-generating pathways of oxidative phosphorylation. In 1955, Hayaishi et al. [Mechanism of the pyrocatechase reaction, J. Am. Chem. Soc. 77 (1955) 5450-5451] presented the most important discovery that changed this simplistic view of how Nature uses atmospheric dioxygen. His discovery, the naming and mechanistic understanding of the first "oxygenase" enzyme, has provided a wonderful opportunity and scientific impetus for four decades of researchers. This volume provides an opportunity to recognize the breakthroughs of the "Hayaishi School." Notable have been the prolific contributions of Professor Ishimura et al. [Oxygen and life. Oxygenases, Oxidases and Lipid Mediators, International Congress Series, Elsevier, Amsterdam, 2002], a first-generation Hayaishi product, to characterization of the cytochrome P450 monooxygenases.}, number={1}, journal={Biochemical and Biophysical Research Communications}, author={Sligar, S.G. and Makris, T.M. and Denisov, I.G.}, year={2005}, pages={346–354} }
 @article{jin_makris_bryson_sligar_dawson_2003, title={Epoxidation of olefins by hydroperoxo-ferric cytochrome P450}, volume={125}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0242585454&partnerID=MN8TOARS}, DOI={10.1021/ja029272n}, abstractNote={The T252A mutant of cytochrome P450cam is unable to form the oxoferryl "active oxygen" intermediate, as judged by its inability to hydroxylate its normal substrate, camphor. In the present study, we demonstrate that T252A P450cam is nonetheless able to epoxidize olefins, due to the action of a second oxidant. However, as shown in earlier radiolytic studies and by the ability of T252A to reduce dioxygen to hydrogen peroxide, the mutant retains the ability to form the hydroperoxo-ferric reaction cycle intermediate. The present results provide strong evidence that hydroperoxo-ferric P450 can serve as a second electrophilic oxidant capable of olefin epoxidation.}, number={12}, journal={Journal of the American Chemical Society}, author={Jin, S. and Makris, T.M. and Bryson, T.A. and Sligar, S.G. and Dawson, J.H.}, year={2003}, pages={3406–3407} }
 @article{makris_denisov_sligar_2003, title={Haem-oxygen reactive intermediates: Catalysis by the two-step}, volume={31}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0038541790&partnerID=MN8TOARS}, DOI={10.1042/BST0310516}, abstractNote={The catalytic schemes of a variety of haem enzymes, including the P450 mono-oxygenases, consist of a number of common reactive haem-oxygen adducts. The characterization of these intermediates by optical and EPR spectroscopies has reinforced the similarity of these intermediate states in a number of haem enzyme systems. Furthermore, the reactivity of these states in P450 and horseradish peroxidase, in which multiple potent oxidants are formed, provides a paradigm for many other haem enzymes.}, number={3}, journal={Biochemical Society Transactions}, author={Makris, T.M. and Denisov, I.G. and Sligar, S.G.}, year={2003}, pages={516–519} }
 @article{ibrahim_denisov_makris_kincaid_sligar_2003, title={Resonance Raman Spectroscopic Studies of Hydroperoxo-Myoglobin at Cryogenic Temperatures}, volume={125}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0242490629&partnerID=MN8TOARS}, DOI={10.1021/ja036949d}, abstractNote={In agreement with previous reports (Gasyna, Z. FEBS Lett. 1979, 106, 213-218 and Leibl, W.; Nitschke, W.; Huettermann, J. Biochim. Biophys. Acta 1986, 870, 20-30) radiolytically reduced samples of oxygenated myoglobin at cryogenic temperatures have been shown by optical absorption and EPR studies to produce directly the peroxo-bound myoglobin at 77 K. Annealing to temperatures near 185 K induces proton transfer, resulting in the formation of the hydroperoxo heme derivative. Resonance Raman studies of the annealed samples has permitted, for the first time, the direct observation of the key nu(Fe-O) stretching mode of the physiologically important Fe-OOH fragment of this ubiquitous intermediate. The assignment of this mode to a feature appearing at 617 cm(-1) is strongly supported by documentation of a 25 cm(-1) shift to lower energy upon substitution with (18)O(2) and by a 5 cm(-1) shift to lower energy for samples prepared in solutions of deuterated solvent.}, number={45}, journal={Journal of the American Chemical Society}, author={Ibrahim, M. and Denisov, I.G. and Makris, T.M. and Kincaid, J.R. and Sligar, S.G.}, year={2003}, pages={13714–13718} }
 @article{denisov_makris_sugar_2002, title={Cryoradiolysis for the study of P450 reaction intermediates}, volume={357}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0036029799&partnerID=MN8TOARS}, DOI={10.1016/s0076-6879(02)57670-9}, abstractNote={This chapter describes cryoradiolysis for the study of p450 reaction intermediates. Cryogenic entrapment is generally used in matrix isolation chemistry for structural and spectroscopic studies. A similar method has been adapted for biochemical needs in mechanistic studies of cytochrome P450cam and heme oxygenase. The method is based on preparing the precursor (oxyferrous heme complex) at ambient conditions, freezing it at 77 K, and irradiating it with high-energy photons (X-rays or gamma rays from a 6°C source). The chapter describes radiolysis. Radiolysis of the solvent water and glycerol provides electrons that reduce the oxyferrous heme complex and turn it into the active peroxo-heme or hydroperoxoheme complex. Working at cryogenic temperature in the frozen solution incorporates the advantages of radiolysis and avoids its drawbacks, the most important advantage being the multiple side reactions with different radical products of radiolysis. The majority of results on radiolysis of simple substances are obtained using gamma rays.}, journal={Cytochrome P450 Part C}, publisher={Elsevier BV}, author={Denisov, Ilia G. and Makris, Thomas M. and Sugar, Stephen G.}, year={2002}, pages={103–115} }
 @article{denisov_makris_sligar_2002, title={Formation and decay of hydroperoxo-ferric heme complex in horseradish peroxidase studied by cryoradiolysis}, volume={277}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0037044754&partnerID=MN8TOARS}, DOI={10.1074/jbc.M207949200}, abstractNote={Using radiolytic reduction of the oxy-ferrous horseradish peroxidase (HRP) at 77 K, we observed the formation and decay of the putative intermediate, the hydroperoxo-ferric heme complex, often called “Compound 0.” This intermediate is common for several different enzyme systems as the precursor of the Compound I (ferryl-oxo π-cation radical) intermediate. EPR and UV-visible absorption spectra show that protonation of the primary intermediate of radiolytic reduction, the peroxo-ferric complex, to form the hydroperoxo-ferric complex is completed only after annealing at temperatures 150–180 K. After further annealing at 195–205 K, this complex directly transforms to ferric HRP without any observable intervening species. The lack of Compound I formation is explained by inability of the enzyme to deliver the second proton to the distal oxygen atom of hydroperoxide ligand, shown to be necessary for dioxygen bond heterolysis on the “oxidase pathway,” which is non-physiological for HRP. Alternatively, the physiological substrate H2O2 brings both protons to the active site of HRP, and Compound I is subsequently formed via rearrangement of the proton from the proximal to the distal oxygen atom of the bound peroxide.}, number={45}, journal={Journal of Biological Chemistry}, author={Denisov, I.G. and Makris, T.M. and Sligar, S.G.}, year={2002}, pages={42706–42710} }
 @article{makris_davydov_denisov_hoffman_sligar_2002, title={Mechanistic enzymology of oxygen activation by the cytochromes P450}, volume={34}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-1842842895&partnerID=MN8TOARS}, DOI={10.1081/DMR-120015691}, abstractNote={The P450 cytochromes represent a universal class of heme-monooxygenases. The detailed mechanistic understanding of their oxidative prowess is a critical theme in the studies of metabolism of a wide range of organic compounds including xenobiotics. Integral to the O2 bond cleavage mechanism by P450 is the enzyme's concerted use of protein and solvent-mediated proton transfer events to transform reduced dioxygen to a species capable of oxidative chemistry. To this end, a wide range of kinetic, structural, and mutagenesis data has been accrued. A critical role of conserved acid-alcohol residues in the P450 distal pocket, as well as stabilized waters, enables the enzyme to catalyze effective monooxygenation chemistry. In this review, we discuss the detailed mechanism of P450 dioxygen scission utilizing the CYP101 hydroxylation of camphor as a model system. The application of low-temperature radiolytic techniques has enabled a structural and spectroscopic analysis of the nature of critical intermediate states in the reaction.}, number={4}, journal={Drug Metabolism Reviews}, author={Makris, T.M. and Davydov, R. and Denisov, I.G. and Hoffman, B.M. and Sligar, S.G.}, year={2002}, pages={691–708} }
 @article{denisov_makris_sligar_2001, title={Cryotrapped Reaction Intermediates of Cytochrome P450 Studied by Radiolytic Reduction with Phosphorus-32}, volume={276}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0035853766&partnerID=MN8TOARS}, DOI={10.1074/jbc.M010219200}, abstractNote={Unstable reaction intermediates of the cytochrome P450 catalytic cycle have been prepared at cryogenic temperatures using radiolytic one-electron reduction of the oxy-P450 CYP101 complex. Since a rate-limiting step in the catalytic cycle of the enzyme is the reduction of the ferrous oxygenated heme protein, subsequent reaction intermediates do not normally accumulate. Using 60Co γ-irradiation, the primary reduced oxy-P450 species at 77 K has been identified as a superoxo- or hydroperoxo-Fe3+-heme complex (Davydov, R., Macdonald, I. D. G., Makris, T. M., Sligar, S. G., and Hoffman, B. M. (1999)J. Am. Chem. Soc. 121, 10654–10655). The electronic absorption spectroscopy is an essential tool to characterize cytochrome P450 intermediates and complements paramagnetic methods, which are blind to important diamagnetic or antiferromagnetically coupled states. We report a method of trapping unstable states of redox enzymes using phosphorus-32 as an internal source of electrons. We determine the UV-visible optical spectra of the reduced oxygenated state of CYP101 and show that the primary intermediate, a hydroperoxo-P450, is stable below 180 K and converts smoothly to the product complex at ∼195 K. In the course of the thermal annealing, no spectral changes indicating the presence of oxoferryl species (the so-called compound I type spectrum) was observed.}, number={15}, journal={Journal of Biological Chemistry}, author={Denisov, I.G. and Makris, T.M. and Sligar, S.G.}, year={2001}, pages={11648–11652} }
 @article{davydov_makris_kofman_werst_sligar_hoffman_2001, title={Hydroxylation of camphor by reduced oxy-cytochrome p450cam: Mechanistic implications of EPR and ENDOR studies of catalytic intermediates in native and mutant enzymes}, volume={123}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0035925164&partnerID=MN8TOARS}, DOI={10.1021/ja003583l}, abstractNote={We have employed gamma-irradiation at cryogenic temperatures (77 K and also approximately 6 K) of the ternary complexes of camphor, dioxygen, and ferro-cytochrome P450cam to inject the "second" electron of the catalytic process. We have used EPR and ENDOR spectroscopies to characterize the primary product of reduction as well as subsequent states created by annealing reduced oxyP450, both the WT enzyme and the D251N and T252A mutants, at progressively higher temperatures. (i) The primary product upon reduction of oxyP450 4 is the end-on, "H-bonded peroxo" intermediate 5A. (ii) This converts even at cryogenic temperatures to the hydroperoxo-ferriheme species, 5B, in a step that is sensitive to these mutations. Yields of 5B are as high as 40%. (iii) In WT and D251N P450s, brief annealing in a narrow temperature range around 200 K causes 5B to convert to a product state, 7A, in which the product 5-exo-hydroxycamphor is coordinated to the ferriheme in a nonequilibrium configuration. Chemical and EPR quantitations indicate the reaction pathway involving 5B yields 5-exo-hydroxycamphor quantitatively. Analogous (but less extensive) results are seen for the alternate substrate, adamantane. (iv) Although the T252A mutation does not interfere with the formation of 5B, the cryoreduced oxyT252A does not yield product, which suggests that 5B is a key intermediate at or near the branch-point that leads either to product formation or to nonproductive "uncoupling" and H(2)O(2) production. The D251N mutation appears to perturb multiple stages in the catalytic cycle. (v) There is no spectroscopic evidence for the buildup of a high-valence oxyferryl/porphyrin pi-cation radical intermediate, 6. However, ENDOR spectroscopy of 7A in H(2)O and D(2)O buffers shows that 7A contains hydroxycamphor, rather than water, bound to Fe(3+), and that the proton removed from the C(5) carbon of substrate during hydroxylation is trapped as the hydroxyl proton. This demonstrates that hydroxylation of substrates by P450cam in fact occurs by the formation and reaction of 6. (vi) Annealing at > or = 220 K converts the initial product state 7A to the equilibrium product state 7, with the transition occurring via a second nonequilibrium product state, 7B, in the D251N mutant; in states 7B and 7 the hydroxycamphor hydroxyl proton no longer is trapped. (vii) The present results are discussed in the context of other efforts to detect intermediates in the P450 catalytic cycle.}, number={7}, journal={Journal of the American Chemical Society}, author={Davydov, R. and Makris, T.M. and Kofman, V. and Werst, D.E. and Sligar, S.G. and Hoffman, B.M.}, year={2001}, pages={1403–1415} }
 @article{davydov_macdonald_makris_sugar_hoffman_1999, title={EPR and ENDOR of catalytic intermediates in cryoreduced native and mutant oxy-cytochromes P450cam: Mutation-induced changes in the proton delivery system [15]}, volume={121}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0033579110&partnerID=MN8TOARS}, DOI={10.1021/ja9918829}, abstractNote={ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTEPR and ENDOR of Catalytic Intermediates in Cryoreduced Native and Mutant Oxy-Cytochromes P450cam: Mutation-Induced Changes in the Proton Delivery SystemRoman Davydov, Iain D. G. Macdonald, Thomas M. Makris, Stephen G. Sligar, and Brian M. HoffmanView Author Information The Department of Chemistry, Northwestern University Evanston, Illinois 60201 The Beckman Institute Departments of Chemistry and Biochemistry and the Center for Biophysics, University of Illinois Urbana Illinois 61801 Cite this: J. Am. Chem. Soc. 1999, 121, 45, 10654–10655Publication Date (Web):October 30, 1999Publication History Received7 June 1999Revised30 September 1999Published online30 October 1999Published inissue 1 November 1999https://doi.org/10.1021/ja9918829Copyright © 1999 American Chemical SocietyRequest reuse permissionsArticle Views667Altmetric-Citations111LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (74 KB) Get e-AlertscloseSUBJECTS:Annealing (metallurgy),Catalysis,Electron paramagnetic resonance spectroscopy,Genetics,Peptides and proteins Get e-Alerts}, number={45}, journal={Journal of the American Chemical Society}, author={Davydov, R. and Macdonald, I.D.G. and Makris, T.M. and Sugar, S.G. and Hoffman, B.M.}, year={1999}, pages={10654–10655} }