Carboxypeptidase B (EC3.4.17.2, protaminase, pancreatic carboxypeptidase B, tissue carboxypeptidase B, peptidyl-L-lysine [L-arginine]hydrolase) is a carboxypeptidase that preferentially cleaves off basic amino acidsarginine and lysine from the C-terminus of a peptide.[1][2][3][4] This enzyme is secreted by the pancreas, and it travels to the small intestine, where it aids in protein digestion. Plasma carboxypeptidase B (carboxypeptidase B2) is responsible for converting the C5aprotein into C5a des-Arg, with one less amino acid.
^Brodrick JW, Geokas MC, Largman C (December 1976). "Human carboxypeptidase B. II. Purification of the enzyme from pancreatic tissue and comparison with the enzymes present in pancreatic secretion". Biochimica et Biophysica Acta (BBA) - Enzymology. 452 (2): 468–81. doi:10.1016/0005-2744(76)90197-2. PMID1009123.
^Butterworth J, Duncan JJ (September 1979). "Carboxypeptidase B activity of cultured skin fibroblasts and relationship to cystic fibrosis". Clinica Chimica Acta; International Journal of Clinical Chemistry. 97 (1): 39–43. doi:10.1016/0009-8981(79)90023-8. PMID40714.
^Wallace EF, Evans CJ, Jurik SM, Mefford IN, Barchas JD (1982). "Carboxypeptidase B activity from adrenal medulla--is it involved in the processing of proenkephalin?". Life Sciences. 31 (16–17): 1793–6. doi:10.1016/0024-3205(82)90212-0. PMID6130442.
