title: Amino acid sequences of two trypsin inhibitors from winged bean seeds (Psophocarpus tetragonolobus (L)DC.).
abstract: The trypsin inhibitor (WTI-1) purified from winged bean seeds is a Kunitz type protease inhibitor having a molecular weight of 19,200. WTI-1 inhibits bovine trypsin stoichiometrically, but not bovine alpha-chymotrypsin. The approximate Ki value for the trypsin-inhibitor complex is 2.5 X 10(-9) M. The complete amino acid sequence of WTI-1 was determined by conventional methods. Comparison of the sequence with that of soybean trypsin inhibitor (STI) indicated that the sequence of WTI-1 had 50% homology with that of STI. WTI-1 was separated into 2 homologous inhibitors, WTI-1A and WTI-1B, by isoelectric focusing. The isoelectric points of WTI-1A and WTI-1B were 8.5 and 9.4, respectively, and their sequences were presumed from their amino acid compositions.
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002417:Cattle; D002918:Chymotrypsin / Q000378:metabolism; D007700:Kinetics; D008970:Molecular Weight; D010446:Peptide Fragments / Q000032:analysis; D012639:Seeds / Q000032:analysis*; D014357:Trypsin / Q000378:metabolism; D014361:Trypsin Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D000596:Amino Acids; D010446:Peptide Fragments; D014361:Trypsin Inhibitors; D002918:Chymotrypsin; D014357:Trypsin