Active-site labeling of rat and human urinary kallikrein by chloro(N alpha-p-tosyllysyl)methane.
This is the first report to demonstrate that chloro(N alpha-p-tosyllysyl)methane (TosLys-CH2Cl) inhibits mammalian glandular kallikrein activities. The inhibitory effect of TosLysCH2Cl on purified rat urinary kallikrein was carried out with three assay methods: 1) Tos-Arg-OMe hydrolysis activity measured by a radiochemical method; 2) kininogenase activity using purified bovine low molecular weight kininogen as substrate and the released kinins subsequently measured by radioimmunoassay; 3) bioassay using isolated rat uterus preparation. Purified rat urinary kallikrein was inhibited by TolLysCH2Cl in a dose and time-dependent manner with all three methods used. The inhibition of purified human urinary kallikrein esterase and kinin-releasing activities were also demonstrated. The results indicate that TosLysCH2Cl inactivates kallikrein activity and support the notion that reactive histidine residue(s) participates in the active center of Kallikrein for catalysis.
D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology*; D000818:Animals; D001665:Binding Sites; D001681:Biological Assay; D001920:Bradykinin / Q000494:pharmacology; D005260:Female; D006801:Humans; D007610:Kallikreins / Q000378:metabolism / Q000494:pharmacology / Q000652:urine*; D007700:Kinetics; D051381:Rats; D014107:Tosyllysine Chloromethyl Ketone / Q000494:pharmacology*; D014590:Uterine Contraction / Q000187:drug effects
D000590:Amino Acid Chloromethyl Ketones; D014107:Tosyllysine Chloromethyl Ketone; D007610:Kallikreins; D001920:Bradykinin