@article{nuruzzaman_colella_uzoewulu_meo_gross_ishizawa_sana_zhang_hoff_medlock_et al._2024, title={Hexafluoroisopropanol as a Bioconjugation Medium of Ultrafast, Tryptophan-Selective Catalysis}, volume={2}, ISSN={["1520-5126"]}, DOI={10.1021/jacs.3c13447}, abstractNote={The past decade has seen a remarkable growth in the number of bioconjugation techniques in chemistry, biology, material science, and biomedical fields. A core design element in bioconjugation technology is a chemical reaction that can form a covalent bond between the protein of interest and the labeling reagent. Achieving chemoselective protein bioconjugation in aqueous media is challenging, especially for generally less reactive amino acid residues, such as tryptophan. We present here the development of tryptophan-selective bioconjugation methods through ultrafast Lewis acid-catalyzed reactions in hexafluoroisopropanol (HFIP). Structure-reactivity relationship studies have revealed a combination of thiophene and ethanol moieties to give a suitable labeling reagent for this bioconjugation process, which enables modification of peptides and proteins in an extremely rapid reaction unencumbered by noticeable side reactions. The capability of the labeling method also facilitated radiofluorination application as well as antibody functionalization. Enhancement of an α-helix by HFIP leads to its compatibility with a certain protein, and this report also demonstrates a further stabilization strategy achieved by the addition of an ionic liquid to the HFIP medium. The nonaqueous bioconjugation approaches allow access to numerous chemical reactions that are unavailable in traditional aqueous processes and will further advance the chemistry of proteins.}, journal={JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, author={Nuruzzaman, Mohammad and Colella, Brandon M. and Uzoewulu, Chiamaka P. and Meo, Alissa E. and Gross, Elizabeth J. and Ishizawa, Seiya and Sana, Sravani and Zhang, He and Hoff, Meredith E. and Medlock, Bryce T. W. and et al.}, year={2024}, month={Feb} } @article{nuruzzaman_colella_nizam_cho_zagorski_ohata_2024, title={Redox-neutral, metal-free tryptophan labeling of polypeptides in hexafluoroisopropanol (HFIP)}, volume={8}, ISSN={["2633-0679"]}, url={https://doi.org/10.1039/D4CB00142G}, DOI={10.1039/d4cb00142g}, abstractNote={This work translated the preceding metal-catalyzed tryptophan modification method into a metal-free process, enabling efficient labeling of peptides, proteins, and even cell lysates in hexafluoroisopropanol (HFIP).}, journal={RSC CHEMICAL BIOLOGY}, author={Nuruzzaman, Mohammad and Colella, Brandon M. and Nizam, Zeinab M. and Cho, Isaac JiHoon and Zagorski, Julia and Ohata, Jun}, year={2024}, month={Aug} }