Carboxypeptidases
| Carboxypeptidases | ||
|---|---|---|
| Enzyme classification | ||
| EC, category | 3.4.16 , hydrolase | |
| Substrate | Peptides and proteins | |
Carboxypeptidases are enzymes that catalyze hydrolytic cleavage of peptide bonds from the C-terminal end. That is why they are exopeptidases .
Two eponymous representatives of this group are carboxypeptidase A (EC 3.4.17.1, CAS 11075-17-5) and carboxypeptidase B (EC 3.4.17.2, CAS 9025-24-5). Both are metalloproteases , which arise from their precursors ( procarboxypeptidases ) by trypsin by means of limited proteolysis and which attack proteins at the end ( exopeptidases ). They are secreted by the exocrine pancreas .
Carboxypeptidase A splits into neutral and partly acidic amino acids . Carboxypeptidase B cleaves basic amino acids. Carboxypeptidase G2 acts as an antidote in methotrexate poisoning by splitting off the glutamic acid residue.
Web links
- MeSH carboxypeptidases
- Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB): Enzyme Nomenclature. Recommendations.
- ExPASy: Enzyme nomenclature database