title: Studies on soybean trypsin inhibitors. X. Isolation and partial characterization of four soybean double-headed proteinase inhibitors.
abstract: Four Bowman-Birk type double-headed inhibitors (B, C-II, D-II, and E-I) were isolated from soybeans. Inhibitor B was different from Bowman-Birk inhibitor only in chromatographic behavior. One mole of C-II inhibited one mole each of bovine trypsin and bovine alpha-chymotrypsin, probably at the same site, and porcine elastase at another reactive site. In the ordinary assay system D-II and E-I inhibited only trypsin activity at a non-stoichiometric inhibitor-enzyme ratio of 1:1.4, and the complexes had rather high dissociation constants. These inhibitors were all inactive toward subtilisin BPN'.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D007700:Kinetics; D011480:Protease Inhibitors; D014358:Trypsin Inhibitor, Bowman-Birk Soybean / Q000302:isolation & purification / Q000494:pharmacology; D014361:Trypsin Inhibitors / Q000302:isolation & purification
chemical_list: D000596:Amino Acids; D011480:Protease Inhibitors; D014358:Trypsin Inhibitor, Bowman-Birk Soybean; D014361:Trypsin Inhibitors