Human mast cell proteases hydrolyze neurotensin, kinetensin and Leu5-enkephalin.
Purified mast cell carboxypeptidase cleaved the C-terminal leucines from Leu5-enkephalin (Leu-ENK), neurotensin (NT), and kinetensin (KT), with Km values of 36, 16, and 15 microM, and kcat values of 44, 51, and 53 s-1, respectively. To better predict potential in vivo hydrolysis products generated by mast cell proteases, these peptides were incubated with released skin mast cell supernatants. Leu5-enkephalin was hydrolyzed only by carboxypeptidase. Kinetensin was cleaved by tryptase, chymase, and carboxypeptidase to yield KT(1-3), KT(1-7), KT(1-8), KT(4-7), and KT(4-8), the last two peptides by the concerted action of two of the proteases. NT(1-11) and NT(1-12) were generated from neurotensin by chymase and carboxypeptidase, respectively.
Goldstein
S M
SM
Department of Dermatology, University of California, San Francisco 94143-0536.
Leong
J
J
Bunnett
N W
NW
D000595:Amino Acid Sequence; D053818:Chymases; D004743:Enkephalin, Leucine / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008407:Mast Cells / Q000201:enzymology; D008969:Molecular Sequence Data; D009496:Neurotensin / Q000378:metabolism*; D009842:Oligopeptides / Q000378:metabolism*; D012697:Serine Endopeptidases / Q000302:isolation & purification / Q000378:metabolism*; D012867:Skin / Q000166:cytology / Q000201:enzymology; D013379:Substrate Specificity
D009842:Oligopeptides; C048812:kinetensin; D009496:Neurotensin; D004743:Enkephalin, Leucine; D012697:Serine Endopeptidases; D053818:Chymases