Karboxypeptidáz

Karboxypeptidáz is a type of enzyme that catalyzes the hydrolysis of peptide bonds at the carboxyl terminus of proteins or peptides. This means it cleaves amino acids one by one from the C-terminal end of a polypeptide chain. There are several types of karboxypeptidases, broadly categorized into serine karboxypeptidases and metallo karboxypeptidases, depending on the catalytic mechanism.

Serine karboxypeptidases, such as karboxypeptidase A, utilize a serine residue in their active site for catalysis. These enzymes are commonly found in the digestive system of animals, where they play a crucial role in breaking down dietary proteins into smaller peptides and amino acids that can be absorbed. Karboxypeptidase A, for instance, is secreted by the pancreas and functions in the small intestine.

Metallo karboxypeptidases, like karboxypeptidase B, require a metal ion, typically zinc, for their activity. Karboxypeptidase B is also involved in protein digestion, specifically cleaving basic amino acids (like arginine and lysine) from the C-terminus. Beyond digestion, karboxypeptidases are implicated in various physiological processes, including blood coagulation, hormone processing, and the regulation of neurotransmitter levels. Research also explores their potential in therapeutic applications.