Karboxipeptidases

Carboxypeptidases are a class of peptidases (enzymes that break down proteins and peptides) that cleave a single amino acid residue from the carboxyl-terminal end of a peptide chain. They are also known as carboxypeptidases or exopeptidases. These enzymes play crucial roles in various biological processes, including digestion, protein turnover, and the processing of peptide hormones. Carboxypeptidases can be further classified based on the catalytic mechanism they employ, most notably as serine carboxypeptidases, zinc carboxypeptidases, and cysteine carboxypeptidases.

In digestion, pancreatic carboxypeptidases, such as carboxypeptidase A and carboxypeptidase B, are secreted into the small intestine to break down dietary proteins into smaller peptides and amino acids that can be absorbed. Carboxypeptidase A primarily cleaves aromatic and aliphatic amino acids, while carboxypeptidase B is specific for basic amino acids like arginine and lysine. Beyond digestion, carboxypeptidases are involved in the maturation of prohormones, the regulation of neurotransmitter levels, and the removal of misfolded proteins. Their activity is often tightly regulated to ensure proper protein processing and prevent uncontrolled degradation.