NoteTrypsin Hydrolysis of the Tyr ( 42 )-Ser ( 43 ) Bond , the Chymotr Bond , of Faba Bean Bowman-Birk Type Inhibitor ypsin Reactiye-site Peptide

offababeanCVicia.fubaL.)2)andhavereportedonthecornpleteaminoacid sequence,i} During the sequencing study, we also tried the preparation of "modified (reaetive site cleaved)" inhibitors by treatment with TPCK-trypsin er TLCK-chymetrypsin at an acid pH. Enzymatic medification of FBI with a catalytic amount of chymotrypsin resulted in the formation of a rnodified inibitor, whose Tyr(42)-Ser(43), the chyrnotrypsin reactiye-site peptide bond,3) was specifically hydrelyzed. On the other hand, the modification with trypsin caused the formation of two modified inhibitor species, TMI-I and TMI-II.i) TMI-I was found te be