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Updated: Aug 18, 2026

Unraveling Entropic Rate Acceleration Induced by Solvent Dynamics in Membrane Enzymes
Published on: January 16, 2016
Pseudo First-Order Cleavage of an Immobilized Substrate by an Enzyme Undergoing Two-Dimensional Surface Diffusion
1Department of Chemistry, Stanford University, Stanford, California, 94305-5025
Abstract:
In this paper we study the reaction kinetics of an enzyme adsorbed on a peptide substrate surface. Although the adsorption is effectively irreversible, the enzyme is able to diffuse on the surface. Our reaction system consisted of the enzyme collagenase and the oligopeptide FALGPA, a substrate for the enzyme. A quartz surface was coated with covalently bound substrate molecules. The extent of reaction was monitored continuously in a flow cell via UV absorption. The data are compatible with a kinetic model based on a pseudo first-order diffusion/orientation rate-limiting step followed by a relatively fast chemical cleavage step. This model was validated by examining the pH dependence of the rate constant. Copyright 1999 Academic Press.
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