title: Purification and characterization of proteinase inhibitors from winged bean (Psophocarpus tetragonolobus (L.) DC.) seeds.
abstract: Seven proteinase inhibitors were isolated from winged bean seeds by ion-exchange chromatographies. These inhibitors had molecular weights of around 20,000, included four half-cystine residues, and were Kunitz-type inhibitors. Two (WTI-2 and 3) inhibited bovine trypsin strongly and four (WCI-1, 2, 3, and 4) inhibited bovine alpha-chymotrypsin, but in different ways. One mole of WCI-2 or -3 could inhibit 2 mol of alpha-chymotrypsin. The remaining inhibitor (WTCI-1) could bind both bovine trypsin and alpha-chymotrypsin at the molar ratio of 1:1, but not simultaneously. All four chymotrypsin inhibitors cross-reacted with rabbit anti-WCI-3 serum, while the other inhibitors did not.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D002848:Chromatography, DEAE-Cellulose / Q000379:methods; D002850:Chromatography, Gel / Q000379:methods; D002918:Chymotrypsin / Q000037:antagonists & inhibitors; D004591:Electrophoresis, Polyacrylamide Gel; D007887:Fabaceae / Q000032:analysis*; D005779:Immunodiffusion; D007526:Isoelectric Point; D008970:Molecular Weight; D010946:Plants, Medicinal; D011480:Protease Inhibitors / Q000302:isolation & purification*; D012639:Seeds / Q000032:analysis*; D014361:Trypsin Inhibitors
chemical_list: D000596:Amino Acids; D011480:Protease Inhibitors; D014361:Trypsin Inhibitors; D002918:Chymotrypsin