title: cDNA cloning of a heterogeneous two-chain anticoagulant protein IX-bp.
abstract: IX-bp and IX/X-bp are heterogeneous two-chain anticoagulant proteins isolated from the venom of habu snake, Trimeresurus flavoviridis. The amino acid sequence of one (B chain) of their two chains is identical. We recently reported the cloning of cDNA encoding the B chain and that of the A chain of IX/X-bp. Here, we report the isolation and characterization of cDNA clones encoding the A chain of IX-bp. The 697-bp sequence showed a putative ORF capable of encoding a 152-amino-acid protein containing a 23-amino-acid signal peptide. The overall amino acid sequence identity between the pre-A chain of IX-bp and that of IX/X-bp is 84%, whereas the cDNA sequence identity of the two ORFs is 91% indicating that habu snake acquired the variety of venom proteins by efficient mutations of antonymous sites.
authors.affiliation: Department of Biochemistry, Meiji College of Pharmacy, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Atoda
authors.forename: E
authors.initials: E
authors.lastname: Yoshihara
authors.forename: M
authors.initials: M
authors.lastname: Yamada
authors.forename: T
authors.initials: T
authors.lastname: Morita
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D003435:Crotalid Venoms / Q000737:chemistry / Q000235:genetics*; D018076:DNA, Complementary / Q000235:genetics; D005796:Genes; D008969:Molecular Sequence Data; D030162:Reptilian Proteins; D016415:Sequence Alignment; D017385:Sequence Homology; D017841:Trimeresurus / Q000235:genetics*
chemical_list: D002352:Carrier Proteins; D003435:Crotalid Venoms; D018076:DNA, Complementary; D030162:Reptilian Proteins; C029748:Trimeresurus venoms; C109516:factor IX-binding protein, Trimeresurus flavoviridis; C070302:factor IX-factor X-binding protein, Crotalinae