title: Amino acid sequence of the acidic Kunitz-type trypsin inhibitor from winged-bean seed [Psophocarpus tetragonolobus (L.) DC].
abstract: The primary sequence of trypsin inhibitor-2 (WBTI-2) from Psophocarpus tetragonolobus (L.) DC seeds was determined. This inhibitor consists of a single polypeptide chain of 182 amino acids, including four half-cystine residues, and an N-terminal residue of pyroglutamic acid. The sequence of WBTI-2 showed 57% identity to the basic trypsin inhibitor (WBTI-3) and 50% identity to the chymotrypsin inhibitor (WBCI) of winged bean, and 54% identity to the trypsin inhibitor DE-3 from Erythrina latissima seed. The similarity to the soybean Kunitz trypsin inhibitor (40%) and the other Kunitz-type inhibitors from Adenanthera pavonina (30%) and wheat (26%) was much lower. Sequence comparisons indicate that the Psophocarpus and Erythrina inhibitors are more closely related to each other than to other members of the Kunitz inhibitor family.
authors.affiliation: CSIRO, Division of Biotechnology, Parkville Laboratory, Victoria, Australia.
authors.forename: J B
authors.initials: JB
authors.lastname: Caldwell
authors.forename: P M
authors.initials: PM
authors.lastname: Strike
authors.forename: A A
authors.initials: AA
authors.lastname: Kortt
mesh_terms: D000595:Amino Acid Sequence; D002918:Chymotrypsin; D003546:Cysteine Endopeptidases; D007887:Fabaceae; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D010940:Plant Proteins; D010946:Plants, Medicinal; D011751:Pyroglutamyl-Peptidase I; D012689:Sequence Homology, Nucleic Acid; D014357:Trypsin; D014361:Trypsin Inhibitors / Q000737:chemistry*
chemical_list: D010446:Peptide Fragments; D010940:Plant Proteins; D014361:Trypsin Inhibitors; C067097:trypsin inhibitor, Kunitz winged-bean seed; D011751:Pyroglutamyl-Peptidase I; D002918:Chymotrypsin; D014357:Trypsin; D003546:Cysteine Endopeptidases; C019913:clostripain