@article{theriot_du_tove_grunden_2010, title={Improving the catalytic activity of hyperthermophilic Pyrococcus prolidases for detoxification of organophosphorus nerve agents over a broad range of temperatures}, volume={87}, ISSN={0175-7598 1432-0614}, url={http://dx.doi.org/10.1007/s00253-010-2614-3}, DOI={10.1007/s00253-010-2614-3}, abstractNote={Prolidase isolated from the hyperthermophilic archaeon Pyrococcus furiosus has potential for application for decontamination of organophosphorus compounds in certain pesticides and chemical warfare agents under harsh conditions. However, current applications that use an enzyme-based cocktail are limited by poor long-term enzyme stability and low reactivity over a broad range of temperatures. To obtain a better enzyme for OP nerve agent decontamination and to investigate structural factors that influence protein thermostability and thermoactivity, randomly mutated P. furiosus prolidases were prepared by using XL1-red-based mutagenesis and error-prone PCR. An Escherichia coli strain JD1 (lambdaDE3) (auxotrophic for proline [DeltaproA] and having deletions in pepQ and pepP dipeptidases with specificity for proline-containing dipeptides) was constructed for screening mutant P. furiosus prolidase expression plasmids. JD1 (lambdaDE3) cells were transformed with mutated prolidase expression plasmids and plated on minimal media supplemented with 50 muM Leu-Pro as the only source of proline. By using this positive selection, Pyrococcus prolidase mutants with improved activity over a broader range of temperatures were isolated. The activities of the mutants over a broad temperature range were measured for both Xaa-Pro dipeptides and OP nerve agents, and the thermoactivity and thermostability of the mutants were determined.}, number={5}, journal={Applied Microbiology and Biotechnology}, publisher={Springer Science and Business Media LLC}, author={Theriot, Casey M. and Du, Xuelian and Tove, Sherry R. and Grunden, Amy M.}, year={2010}, month={Apr}, pages={1715–1726} }
 @article{theriot_tove_grunden_2009, title={Characterization of two proline dipeptidases (prolidases) from the hyperthermophilic archaeon Pyrococcus horikoshii}, volume={86}, ISSN={0175-7598 1432-0614}, url={http://dx.doi.org/10.1007/s00253-009-2235-x}, DOI={10.1007/s00253-009-2235-x}, abstractNote={Prolidases hydrolyze the unique bond between X-Pro dipeptides and can also cleave the P-F and P-O bonds found in organophosphorus compounds, including the nerve agents, soman and sarin. The advantages of using hyperthermophilic enzymes in biodetoxification strategies are based on their enzyme stability and efficiency. Therefore, it is advantageous to examine new thermostable prolidases for potential use in biotechnological applications. Two thermostable prolidase homologs, PH1149 and PH0974, were identified in the genome of Pyrococcus horikoshii based on their sequences having conserved metal binding and catalytic amino acid residues that are present in other known prolidases, such as the previously characterized Pyrococcus furiosus prolidase. These P. horikoshii prolidases were expressed recombinantly in the Escherichia coli strain BL21 (lambdaDE3), and both were shown to function as proline dipeptidases. Biochemical characterization of these prolidases shows they have higher catalytic activities over a broader pH range, higher affinity for metal and are more stable compared to P. furiosus prolidase. This study has important implications for the potential use of these enzymes in biotechnological applications and provides further information on the functional traits of hyperthermophilic proteins, specifically metalloenzymes.}, number={1}, journal={Applied Microbiology and Biotechnology}, publisher={Springer Science and Business Media LLC}, author={Theriot, Casey M. and Tove, Sherry R. and Grunden, Amy M.}, year={2009}, month={Sep}, pages={177–188} }
 @misc{theriot_tove_grunden_2009, title={biotechnological applications of recombinant microbial prolidases}, volume={68}, journal={Advances in applied microbiology, vol 68}, author={Theriot, C. M. and Tove, S. R. and Grunden, A. M.}, year={2009}, pages={99-} }
 @article{shianna_dotson_tove_parks_2001, title={Identification of a UPC2 homolog in Saccharomyces cerevisiae and its involvement in aerobic sterol uptake}, volume={183}, ISSN={["0021-9193"]}, DOI={10.1128/JB.183.3.830-834.2001}, abstractNote={ABSTRACT}, number={3}, journal={JOURNAL OF BACTERIOLOGY}, author={Shianna, KV and Dotson, WD and Tove, S and Parks, LW}, year={2001}, month={Feb}, pages={830–834} }
 @article{dotson_tove_parks_2000, title={Biochemical modifications and transcriptional alterations attendant to sterol feeding in Phytophthora parasitica}, volume={35}, ISSN={["0024-4201"]}, DOI={10.1007/s11745-000-0519-9}, abstractNote={Abstract}, number={3}, journal={LIPIDS}, author={Dotson, WD and Tove, SR and Parks, LW}, year={2000}, month={Mar}, pages={243–247} }
 @article{leak_tove_parks_1999, title={In yeast, upc2-1 confers a decrease in tolerance to LiCl and NaCl, which can be suppressed by the P-type ATPase encoded by ENA2}, volume={18}, ISSN={["1044-5498"]}, DOI={10.1089/104454999315510}, abstractNote={Wild-type yeast cells are unable to take up sterols from their growth media under aerobic conditions and are relatively resistant to monovalent cations. A yeast mutant (upc2-1) with a defect in the aerobic exclusion of sterols was found to have increased sensitivity to LiCl and NaCl. Although cation sensitivity has been reported for mutants that synthesize altered sterols, the mutant with upc2-1 continues to produce the normal sterol, ergosterol. The ENA2 gene was cloned on the basis of remediating the hypersensitivity to the monovalent cations.}, number={2}, journal={DNA AND CELL BIOLOGY}, author={Leak, FW and Tove, S and Parks, LW}, year={1999}, month={Feb}, pages={133–139} }
 @article{crowley_tove_parks_1998, title={A calcium-dependent ergosterol mutant of Saccharomyces cerevisiae}, volume={34}, ISSN={["1432-0983"]}, DOI={10.1007/s002940050371}, abstractNote={ERG24 is the structural gene for the C14-sterol reductase in yeast. A lack of activity in that enzyme, mediated either by the morpholine fungicides or the insertional inactivation of ERG24, causes the accumulation of the aberrant sterol ignosterol. Cells producing this sterol are unable to grow aerobically in the routine laboratory medium, YPD. However, growth does occur on a synthetic defined medium. A novel calcium-dependent phenotype associated with alterations in the ergosterol biosynthetic pathway in yeast is described. In addition, reduction of yeast growth with an azole inhibitor of the C-14 sterol de-methylase was also modulated by an excess of calcium ions in the culture medium. These results define a new effect of ergosterol deficiency and provide important practical implications for utilizing morpholine and azole sterol biosynthetic-inhibiting fungicides.}, number={2}, journal={CURRENT GENETICS}, author={Crowley, JH and Tove, S and Parks, LW}, year={1998}, month={Aug}, pages={93–99} }
 @article{crowley_leak_shianna_tove_parks_1998, title={A mutation in a purported regulatory gene affects control of sterol uptake in Saccharomyces cerevisiae}, volume={180}, number={16}, journal={Journal of Bacteriology}, author={Crowley, J. H. and Leak, F. W. and Shianna, K. V. and Tove, S. and Parks, L. W.}, year={1998}, pages={4177–4183} }
 @article{tomeo_palermo_tove_parks_1997, title={A conditional sterol esterification defect in yeast having either a SEC1 or SEC5 mutation in the secretory pathway}, volume={13}, DOI={10.1002/(sici)1097-0061(199704)13:5<449::aid-yea99>3.0.co;2-a}, abstractNote={Two temperature‐conditional secretory mutations, sec1 and sec5, cause the accumulation of post‐Golgi vesicles when strains containing these mutations are grown at 37°C. In addition to accumulating vesicles, the mutants do not esterify free sterol on rich media at the restrictive temperature. It is the high level of inositol in the media that causes this condition in the yeast Saccharomyces cerevisiae, not a defective steryl ester synthase or lack of substrates. When strains containing the sec1 or sec5 mutation were transformed separately with a plasmid carrying SEC1 and SEC5, the esterification and secretory defects were alleviated. Double mutants containing sec6, sec14 or sec18 with either a sec1 or sec5 mutation have normal esterification levels. Strains with suppressor mutations were isolated that grew at 37°C, esterified sterols and had diminished accumulation of vesicles, when grown at the restrictive temperature on defined media with additional inositol. Electron microscopy was used to examine vesicle accumulation, the number of lipid droplets, and to further characterize the esterification defect. When grown at 37°C on defined medium, the strains with sec5 or sec1 accumulated the usual secretory vesicles, but when grown under similar conditions with elevated levels of inositol, accumulated an additional vesicular‐like body. © 1997 John Wiley & Sons, Ltd.}, number={5}, journal={Yeast}, author={Tomeo, M. E. and Palermo, L. M. and Tove, S. R. and Parks, L. W.}, year={1997}, pages={449–462} }
 @article{palermo_leak_tove_parks_1997, title={Assessment of the essentiality of ERG genes late in ergosterol biosynthesis in Saccharomyces cerevisiae}, volume={32}, ISSN={["1432-0983"]}, DOI={10.1007/s002940050252}, abstractNote={Isogenic strains of yeast were constructed, differing only in insertionally inactivated genes for ergosterol biosynthesis. These and their allelic wild-types were grown in competition to ascertain growth differences and any selective advantage for organisms producing sterols with or without specific features of ergosterol. In every instance tested, the wild-type allele afforded a competitive advantage over the isogenic pair producing modified sterol structures instead of ergosterol. A general trend was seen in which the earlier in the biosynthetic pathway that a mutation occurred, the less able the strain producing the defective sterols could compete with the ergosterol-producing strains.}, number={2}, journal={CURRENT GENETICS}, author={Palermo, LM and Leak, FW and Tove, S and Parks, LW}, year={1997}, month={Aug}, pages={93–99} }