Substrate and inhibitor studies on proteinase 3.
Various amino acid and peptide thioesters were tested as substrates for human proteinase 3 and the best substrate is Boc-Ala-Ala-Nva-SBzl with a kcat/Km value of 1.0 x 10(6) M-1.s-1. Boc-Ala-Ala-AA-SBzl (AA = Val, Ala, or Met) are also good substrates with kcat/Km values of (1-4) x 10(5) M-1.s-1. Substituted isocoumarins are potent inhibitors of proteinase 3 and the best inhibitors are 7-amino-4-chloro-3-(2-bromoethoxy)isocoumarin and 3,4-dichloroisocoumarin (DCI) with kobs/[I] values of 4700 and 2600 M-1.s-1, respectively. Substituted isocoumarins, peptide phosphonates and chloromethyl ketones inhibited proteinase 3 less potently than human neutrophil elastase (HNE) by 1-2 orders of magnitude.
Kam
C M
CM
School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta 30332.
Kerrigan
J E
JE
Dolman
K M
KM
Goldschmeding
R
R
Von dem Borne
A E
AE
Powers
J C
JC
D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D001345:Autoradiography; D003374:Coumarins / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D006868:Hydrolysis; D007700:Kinetics; D053146:Myeloblastin; D009943:Organophosphorus Compounds / Q000494:pharmacology; D011480:Protease Inhibitors; D012697:Serine Endopeptidases / Q000378:metabolism*; D013379:Substrate Specificity
D000590:Amino Acid Chloromethyl Ketones; D003374:Coumarins; D009943:Organophosphorus Compounds; D011480:Protease Inhibitors; D012697:Serine Endopeptidases; D053146:Myeloblastin