title: Neurokinin B is hydrolysed by synaptic membranes and by endopeptidase-24.11 (enkephalinase) but not by angiotensin converting enzyme.
abstract: The major site of hydrolysis was the Gly8-Leu9 bond. Angiotensin converting enzyme (peptidyl dipeptidase A, EC 3.4.15.1) from pig kidney hydrolysed substance P releasing the C-terminal tripeptide Gly-Leu-MetNH2 but failed to hydrolyse neurokinin B. Pig brain striatal synaptic membranes hydrolysed neurokinin B producing a similar pattern of products as did endopeptidase-24.11. Substantial inhibition of this activity was achieved with the selective inhibitor phosphoramidon. A combination of phosphoramidon and bestatin abolished the hydrolysis of neurokinin B by synaptic membranes. Thus, a bestatin-sensitive aminopeptidase may play a role in the synaptic metabolism of neurokinin B in addition to endopeptidase-24.11. This aminopeptidase appears to be distinct from aminopeptidase N (EC 3.4.11.2).
mesh_terms: D000818:Animals; D003342:Corpus Striatum / Q000378:metabolism; D010450:Endopeptidases / Q000378:metabolism*; D006868:Hydrolysis; D066298:In Vitro Techniques; D007668:Kidney / Q000201:enzymology; D015260:Neprilysin; D015287:Neurokinin B; D009842:Oligopeptides / Q000378:metabolism*; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism*; D013379:Substrate Specificity; D013552:Swine; D013570:Synaptic Membranes / Q000378:metabolism*
chemical_list: D009842:Oligopeptides; D015287:Neurokinin B; D010450:Endopeptidases; D007703:Peptidyl-Dipeptidase A; D015260:Neprilysin