Primary structure of Kunitz-type trypsin inhibitor-2a (pI 5.9) from Psophocarpus tetragonolobus (L.) DC seed.
The primary structure of acidic trypsin inhibitor-2a (WBTI-2a, pI 5.9) from Psophocarpus tetragonolobus (L.) DC seed was determined. This inhibitor consists of a single polypeptide chain of 180 amino acids including four half-cystine residues and has an N-terminal residue of pyroglutamic acid. The sequence of WBTI-2a, pI 5.9, showed 84% identity to acidic trypsin inhibitor-2 (WBTI-2, pI 5.1) but only 57% identity to the basic trypsin inhibitor (WBTI-1, pI 8.9) and 50% identity to the chymotrypsin inhibitor of winged bean. The data indicate that winged bean seed contains a family of three Kunitz-type inhibitors which have about 50% identity.
CSIRO, Division of Biomolecular Engineering, Parkville Laboratory, Victoria, Australia.
A A
AA
Kortt
J E
JE
Burns
J B
JB
Caldwell
T
T
Ferro
P M
PM
Strike
D000595:Amino Acid Sequence; D004591:Electrophoresis, Polyacrylamide Gel; D007887:Fabaceae; D007526:Isoelectric Point; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010940:Plant Proteins; D010946:Plants, Medicinal; D012639:Seeds / Q000737:chemistry*; D012689:Sequence Homology, Nucleic Acid; D014361:Trypsin Inhibitors / Q000737:chemistry*
D010940:Plant Proteins; D014361:Trypsin Inhibitors; C070936:trypsin inhibitor 2a, Kunitz winged-bean seed