BIO NMDCAT ENZYMES

nmdcat.online July 11, 2026

The catalytic triad in serine proteases consists of Asp, His, and Ser. This arrangement allows histidine to act as

A. A competitive inhibitor

B. An irreversible covalent cross-linker

C. A general acid-base catalyst, shuttling protons between serine and the substrate

✓

D. A metal-chelating group

📝 Explanation

The triad allows histidine to act as a powerful general base catalyst, abstracting a proton from the serine hydroxyl group to make it a nucleophile.

📖 Additional Information

A competitive inhibitor
An irreversible covalent cross-linker
A general acid-base catalyst, shuttling protons between serine and the substrate
A metal-chelating group

The triad allows histidine to act as a powerful general base catalyst, abstracting a proton from the serine hydroxyl group to make it a nucleophile.

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