The metabolism of neuropeptides. Neurokinin A (substance K) is a substrate for endopeptidase-24.11 but not for peptidyl dipeptidase A (angiotensin-converting enzyme).
Both endopeptidase-24.11 and peptidyl dipeptidase A have previously been shown to hydrolyse the neuropeptide substance P. The structurally related peptide neurokinin A is also shown to be hydrolysed by pig kidney endopeptidase-24.11. The identified products indicated hydrolysis at two sites, Ser5-Phe6 and Gly8-Leu9, consistent with the known specificity of the enzyme. The pattern of hydrolysis of neurokinin A by synaptic membranes prepared from pig striatum was similar to that observed with purified endopeptidase-24.11, and hydrolysis was substantially abolished by the selective inhibitor phosphoramidon. Peptidyl dipeptidase A purified from pig kidney was shown to hydrolyse substance P but not neurokinin A. It is concluded that endopeptidase-24.11 has the general capacity to hydrolyse and inactivate the family of tachykinin peptides, including substance P and neurokinin A.
D000818:Animals; D010450:Endopeptidases / Q000378:metabolism*; D006868:Hydrolysis; D007668:Kidney / Q000201:enzymology; D015260:Neprilysin; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D015288:Neurokinin A; D015287:Neurokinin B; D009842:Oligopeptides / Q000378:metabolism; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism*; D011480:Protease Inhibitors / Q000494:pharmacology; D013552:Swine; D013570:Synaptic Membranes / Q000378:metabolism
D009419:Nerve Tissue Proteins; D009842:Oligopeptides; D011480:Protease Inhibitors; D015288:Neurokinin A; D015287:Neurokinin B; D010450:Endopeptidases; D007703:Peptidyl-Dipeptidase A; D015260:Neprilysin