title: pH dependence of bovine mast cell tryptase catalytic activity and of its inhibition by 4',6-diamidino-2-phenylindole.
abstract: Tryptases are oligomeric enzymes localized in the secretory granules of mast cells. Their role(s) in vivo has yet to be clarified and the lack of powerful and specific inhibitors has hampered the comprehension of the biological functions of these enzymes. In this paper, we identify 4',6-diamidino-2-phenylindole as a potent inhibitor for bovine tryptase. This inhibitory effect and the enzyme catalyzed hydrolysis of the synthetic substrate Boc-Phe-Ser-Arg-methyl-coumarin were investigated in the pH range of 6.0-9.0. On the basis of the pK shifts occurring upon formation of the inhibitor(substrate)/enzyme complexes, some aminoacidic groups are proposed to play a role in such interactions.
authors.affiliation: Department of Experimental Medicine and Biochemical Sciences, University Tor Vergata, Rome, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Fiorucci
authors.forename: F
authors.initials: F
authors.lastname: Erba
authors.forename: M
authors.initials: M
authors.lastname: Bolognesi
authors.forename: M
authors.initials: M
authors.lastname: Coletta
authors.forename: F
authors.initials: F
authors.lastname: Ascoli
mesh_terms: D000818:Animals; D002417:Cattle; D053818:Chymases; D003374:Coumarins / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007211:Indoles / Q000378:metabolism / Q000494:pharmacology*; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D008407:Mast Cells / Q000201:enzymology*; D015394:Molecular Structure; D009842:Oligopeptides / Q000378:metabolism; D011485:Protein Binding; D012697:Serine Endopeptidases / Q000378:metabolism*; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology; D053802:Tryptases
chemical_list: D003374:Coumarins; D007211:Indoles; D009842:Oligopeptides; D015842:Serine Proteinase Inhibitors; C007293:DAPI; C048055:tertiary-butyloxycarbonyl-phenylalanyl-seryl-arginyl-4-methylcoumarin-7-amide; D012697:Serine Endopeptidases; C083294:chymase 2; D053818:Chymases; D053802:Tryptases