Arrangement of the disulfide bridges in a blood coagulation factor IX/factor X-binding protein from the venom of Trimeresurus flavoviridis.
Blood coagulation factor IX/factor X-binding protein (IX/X-bp) is a two-chain anticoagulant protein that was isolated from the venom of Trimeresurus flavoviridis. The amino acid sequence of IX/X-bp is homologous to the sequences of C-type lectin-like proteins, such as asialoglycoprotein receptor, tetranectin, and the low-affinity Fc epsilon receptor of immunoglobulin E. The amino acid composition and amino acid sequence of cystine-containing peptides, formed as a result of enzymatic digestion of CNBr-generated fragments of IX/X-bp, were analyzed to determine the location of the seven disulfide bridges in the protein. Three disulfide bridges in the A chain link Cys2 to Cys13, Cys30 to Cys127, and Cys102 to Cys119. Three disulfide bridges in the A chain link Cys2 to Cys13, Cys30 to Cys119, and Cys96 to Cys111. An interchain disulfide bond links Cys79 of the A chain and Cys75 of the B chain. The intrachain disulfide-bonding patterns of both the A and B chains of IX/X-bp are similar to those found in other C-type lectin-like proteins. We discuss in this report the sequence homology between IX/X-bp and other two-chain, C-type lectin-like proteins that have been isolated from snake venoms and we compare the S-S bonding patterns of proteins that are homologous to IX/X-bp.
Atoda
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H
Department of Biochemistry, Meiji College of Pharmacy, Tokyo.
Morita
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T
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000925:Anticoagulants / Q000737:chemistry*; D002352:Carrier Proteins / Q000737:chemistry*; D003435:Crotalid Venoms / Q000737:chemistry*; D004220:Disulfides / Q000737:chemistry*; D008969:Molecular Sequence Data; D011487:Protein Conformation; D030162:Reptilian Proteins
D000596:Amino Acids; D000925:Anticoagulants; D002352:Carrier Proteins; D003435:Crotalid Venoms; D004220:Disulfides; D030162:Reptilian Proteins; C029748:Trimeresurus venoms; C070302:factor IX-factor X-binding protein, Crotalinae