L41 BIOL 4810 Lecture Notes - Lecture 35: Covalent Bond, Cysteine, Enzyme
12 May 2020
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Document Summary
Theme & variations: serine & cysteine proteases, covalent acyl-enzyme intermediate that is hydrolyzed, zinc and aspartate proteases, protonated water mechanism. Peptide substrate notation: s = substrate binding site on protease, p = peptide residue. Protease speci city is largely dictated by residues in the s1 site: serine proteases - active site. Crystallographic studies identi ed two key catalytic features: 1. Catalytic triad: enhances nucleophilicity of active site serine: 2. Oxyanion hole: enhances electrophilicity of the substrate: serine proteases - reaction mechanism, serine proteases - t. s. Stabilization: transition state stabilization - "oxyanion hole, serine proteases - experimental evidence, structure of the "acyl-enzyme intermediate, ph 5, transition state stabilization - "oxyanion hole, ph 9, site-directed mutagenesis, 1. 1: serine proteases - engineering substrate spec city, s = substrate binding site on protease, p = peptide residue. Not pro: use a ch peptide substrate. D189s mutant: use a ch peptide substrate.
