Complete amino acid sequence of the lentil trypsin-chymotrypsin inhibitor LCI-1.7 and a discussion of atypical binding sites of Bowman-Birk inhibitors.
The complete primary structure of the lentil (Lens culinaris) trypsin-chymotrypsin inhibitor LCI-1.7 was determined by conventional methods in order to find relationships between partial sequences and the difference in action against human and bovine chymotrypsin. As other Bowman-Birk type inhibitors, LCI-1.7 contained 68 amino acid residues, seven disulfide bridges, and two reactive sites, Arg16-Ser17 for trypsin and Tyr42-Ser43 for chymotrypsin. Evaluation of sequence homologies showed that it belonged to the group III Bowman-Birk inhibitors. The atypical additional binding site of LCI-1.7 for human chymotrypsin was discussed and compared with such binding sites of two other Bowman-Birk inhibitors, the Bowman-Birk soybean proteinase inhibitor BBI, and the lima bean proteinase inhibitor LBI I, for human and bovine trypsin and chymotrypsin. A concept to reduce the action of these inhibitors against human enzymes by genetic engineering was proposed.
Weder
Jürgen K P
JK
Institut für Lebensmittelchemie, Technische Universität München, Lichtenbergstrasse 4, 85748 Garching, Germany. Lebensmittelchemie@lrz.tum.de
Hinkers
Sabine C
SC
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D001665:Binding Sites; D002918:Chymotrypsin / Q000037:antagonists & inhibitors*; D027806:Lens Plant / Q000737:chemistry*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry; D011480:Protease Inhibitors / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry; D016415:Sequence Alignment; D014358:Trypsin Inhibitor, Bowman-Birk Soybean / Q000737:chemistry*; D014361:Trypsin Inhibitors / Q000737:chemistry*
D000596:Amino Acids; D010940:Plant Proteins; D011480:Protease Inhibitors; D014358:Trypsin Inhibitor, Bowman-Birk Soybean; D014361:Trypsin Inhibitors; C025398:protease inhibitor protein, Phaseolus lunatus; D002918:Chymotrypsin