Question: 123. The cofactor of the enzyme carboxypeptidase is :
(1) Zinc
(2) Niacin
(3) Flavin
(4) Haem
Answer: Option (1)
Explanation:
Carboxypeptidase is a proteolytic enzyme that catalyzes the removal of amino acids from the carboxyl terminal of proteins and peptides.
This enzyme requires a metal ion as a cofactor for its catalytic activity.
Zinc ion plays a crucial role in the active site of carboxypeptidase by stabilizing the enzyme–substrate complex and facilitating peptide bond hydrolysis.
Niacin is a vitamin that forms part of coenzymes like NAD and NADP, flavin forms FAD and FMN,
and haem is a prosthetic group in hemoproteins, none of which act as cofactors for carboxypeptidase.
Hence, the cofactor of carboxypeptidase is zinc.