Conformational Stabilization and Rapid Labeling of a 29-Residue Peptide by a Small Molecule Reaction Partner
Author(s)Evans, Ethan Daniel; Gates, Zachary P; Sun, Zhen-Yu J.; Mijalis, Alexander James; Pentelute, Bradley L.
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A 29-residue peptide (MP01), identified by in vitro selection for reactivity with a small molecule perfluoroaromatic, was modified and characterized using experimental and computational techniques, with the goal of understanding the molecular basis of its reactivity. These studies identified a six-amino acid point mutant (MP01-Gen4) that exhibited a reaction rate constant of 25.8 ± 1.8 M-1 s-1 at pH 7.4 and room temperature, approximately 2 orders of magnitude greater than that of its progenitor sequence and 3 orders of magnitude greater than background cysteine reactivity. MP01-Gen4 appeared to be conformationally dynamic and exhibited several properties reminiscent of larger protein molecules, including denaturant-sensitive structure and reactivity. We believe the majority of the reaction rate enhancement can be attributed to interaction of MP01-Gen4 with the perfluoroaromatic probe, which was found to stabilize a helical conformation of both MP01-Gen4 and nonreactive Cys-to-Ser or Cys-to-Ala variants. These findings demonstrate the ability of dynamic peptides to access proteinlike reaction mechanisms and the potential of perfluoroaromatic functionality to stabilize small peptide folds.
DepartmentMassachusetts Institute of Technology. Department of Chemistry
American Chemical Society (ACS)
Evans, Ethan D. et al. "Conformational Stabilization and Rapid Labeling of a 29-Residue Peptide by a Small Molecule Reaction Partner." Biochemistry 58, 10 (February 2019): 1343–1353 © 2019 American Chemical Society.
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