Identification of potential activators of proteinase-activated receptor-2.
In order to identify physiological activators of proteinase-activated receptor-2 (PAR-2), a peptide chloromethane inhibitor (biotinyl-Ser-Lys-Gly-Arg-CH2Cl) based on the cleavage site for activation of PAR-2 was synthesised and tested with 12 trypsin-like serine proteinases. The second-order rate constant (ki/Ki) for the formation of the covalent proteinase-inhibitor complex varied by 2 x 10(5)-fold between the proteinases. Biotinyl-Ser-Lys-Gly-Arg-CH2Cl reacted very rapidly with trypsin, acrosin from sperm and tryptase from mast cells: the ki/Ki values with these proteinases were greater than 10(5) M(-1) x s(-1). Thus, the specificity of these proteinases matched the sequence of the activation site of PAR-2 and it can be concluded that these proteinases are potential physiological activators of PAR-2.
Fox
M T
MT
Department of Haematology, University of Cambridge, MRC Centre, UK. mf.srl@mrc-lmb.cam.ac.uk
Harriott
P
P
Walker
B
B
Stone
S R
SR
D000818:Animals; D001710:Biotin / Q000031:analogs & derivatives / Q000494:pharmacology; D002417:Cattle; D015951:Factor Xa / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D009842:Oligopeptides / Q000494:pharmacology; D044464:Receptor, PAR-2; D011956:Receptors, Cell Surface / Q000378:metabolism*; D012697:Serine Endopeptidases / Q000378:metabolism*; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology*; D013917:Thrombin / Q000378:metabolism
D009842:Oligopeptides; D044464:Receptor, PAR-2; D011956:Receptors, Cell Surface; D015842:Serine Proteinase Inhibitors; C109690:biotinyl-seryl-lysyl-glycyl-arginyl-chloromethane; D001710:Biotin; D012697:Serine Endopeptidases; D013917:Thrombin; D015951:Factor Xa