Pseudo First-Order Cleavage of an Immobilized Substrate by an Enzyme Undergoing Two-Dimensional Surface Diffusion
✍ Scribed by Giuseppe Trigiante; Alice P Gast; Channing R Robertson
- Publisher
- Elsevier Science
- Year
- 1999
- Tongue
- English
- Weight
- 87 KB
- Volume
- 213
- Category
- Article
- ISSN
- 0021-9797
No coin nor oath required. For personal study only.
✦ Synopsis
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 ratelimiting step followed by a relatively fast chemical cleavage step. This model was validated by examining the pH dependence of the rate constant.