Question

The cofactor of the enzyme carboxypeptidase is :

• A. Zinc
• B. Niacin
• C. Flavin
• D. Haem

Answer 1

The Correct Option is A

In the study of enzymes, a cofactor is a non-protein chemical compound that is required for the enzyme's biological activity. Carboxypeptidase is an enzyme that plays a key role in the digestion of proteins by removing amino acid residues from the carboxyl end of a peptide chain. The functionality and catalytic activity of carboxypeptidase depend on the presence of a specific metal ion cofactor.

For carboxypeptidase, the cofactor is: Zinc

Zinc ions (Zn²⁺) are crucial for the enzymatic activity of carboxypeptidase. They facilitate the reaction by stabilizing the enzyme-substrate complex and playing a direct role in the hydrolysis of the peptide bonds. Therefore, zinc acts as a stabilizing agent and helps in the coordination of water molecules necessary for the catalysis process.

This specific requirement for zinc as a cofactor is common among enzymes that belong to the metalloprotease class, which includes carboxypeptidase. The correct functioning and efficiency of carboxypeptidase are significantly compromised without the presence of zinc, demonstrating the metal's essential role in the enzymatic mechanism.