A chemical cross-linking reagent has two reactive ends that can be used to covalently link two different amino acid groups in proteins.The links that result are similar to a disulfide bridge that forms between two cysteine groups.Biochemists use chemical cross-linking reagents to test for conformational changes in proteins because the cross-links often freeze proteins in a single conformation.Which method of increasing reaction rates would be most adversely affected by chemical cross-linking?

Question

Quizplus · Accepted Answer

Chemical cross-linking freezes proteins into a single conformation, which can limit the flexibility required for induced-fit mechanism, making it the most adversely affected method of increasing reaction rates. Metal ion catalysis, covalent catalysis, acid-base catalysis, and substrate orientation do not depend on protein conformation flexibility, and therefore would not be as affected by chemical cross-linking.

A Chemical Cross-Linking Reagent Has Two Reactive Ends That Can