Characterization of a tissue kallikrein inhibitor isolated from Bauhinia bauhinioides seeds: inhibition of the hydrolysis of kininogen related substrates

Trypsin inhibitors were purified from a saline extract of Bauhinia bauhinio ides seeds by ion-exchange column chromatography on DEAE-Sephadex, gel filt ration on Superose 12 column, Mono Q ion-exchange chromatography or, altern atively, by affinity chromatography on trypsin-Sepharose. Both B. bauhinioi des isolated inhibitors, BbTI-I and BbTI-II, inhibit trypsin being the diss ociation constant 0.6 and 0.36 nM, respectively. BbTI-II only inhibits porc ine pancreatic kallikrein hydrolysis of H-Pro-Phe-Arg-AMC (K-i 2.0 nM); the bradykinin-containing sequence LGMISLMKRPPGFSPFRSSRI-NH2 and the two kinin ogen related flanking quenched substrates Abz-MISLMKRP-EDDnp (K-i 2.0 nM) a nd Abz-FRSSRQ-EDDnp (K-i 2.5 nM). (C) 1999 Published by Elsevier Science B. V. All rights reserved.