The complete amino acid sequence of a Kunitz family trypsin inhibitor from seeds of Acacia confusa.
The complete amino acid sequence of a Kunitz-type two-chain trypsin inhibitor was determined for the first time. The sequence of the inhibitor from Acacia confusa (ACTI) was determined by analysis of peptides obtained from the reduced and S-carboxymethylated protein by digestion with endopeptidase Lys-C, endopeptidase Arg-C, and V8 endopeptidase. ACTI is comprised of two chains, namely A and B chains linked by the disulfide bridge between Cys(133) and Cys(141), and the inhibitor consists of 175 amino acid residues, 136 residues in the A-chain and 39 residues in the B-chain. The N-terminal amino acid sequence of ACTI shows extensive homology to the trypsin inhibitors from Acacia elata and Albizzia julibrissin, while the whole amino acid sequence of ACTI has a high degree of homology to the other Kunitz-type trypsin inhibitors from soybeans, winged bean seeds [Psophocarpus tetragonolobus (L) DC.], and seeds of Erythrina species.
Wu
H C
HC
Institute of Biochemistry, College of Medicine, National Taiwan University, Taipei, Republic of China.
Lin
J Y
JY
D000045:Acacia / Q000737:chemistry*; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D010940:Plant Proteins / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D014361:Trypsin Inhibitors / Q000737:chemistry*
D000596:Amino Acids; D010446:Peptide Fragments; D010940:Plant Proteins; D014361:Trypsin Inhibitors; C074637:ACTI protein, Acacia confusa