title: Effect of P2' substituents on kinetic constants for hydrolysis by cysteine proteinases.
abstract: Intramolecularly quenched fluorogenic peptide substrates with the general sequence: DABCYL-Lys-Phe-Gly-Gly-Xxx-Ala-EDANS have been utilized to explore the effect of the hydrophobicity of amino acid side chains in the P2' position on the steady-state kinetic constants for papain catalyzed hydrolysis. The results demonstrate that subsite interactions between the enzyme and the peptide substrate modulate the enzyme specificity by slowing the release of the C-terminal product. This series of substrates can be used to characterize substrate specificity studies of other cysteine proteinases.
authors.affiliation: School of Pharmacy, University of Wisconsin-Madison 53706.
authors.forename: C
authors.initials: C
authors.lastname: García-Echeverría
authors.forename: D H
authors.initials: DH
authors.lastname: Rich
mesh_terms: D000595:Amino Acid Sequence; D005456:Fluorescent Dyes; D006868:Hydrolysis; D007700:Kinetics; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009282:Naphthalenesulfonates; D009842:Oligopeptides / Q000737:chemistry / Q000378:metabolism*; D010206:Papain / Q000378:metabolism*; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
chemical_list: D005456:Fluorescent Dyes; D009282:Naphthalenesulfonates; D009842:Oligopeptides; C063126:5-((2-aminoethyl)amino)naphthalene-1-sulfonic acid; D010206:Papain