Biomaterial Database

Blood coagulation factor IX-binding protein from the venom of Trimeresurus flavoviridis: purification and characterization. 1995

H Atoda, and M Ishikawa, and E Yoshihara, and F Sekiya, and T Morita

Department of Biochemistry, Meiji College of Pharmacy, Tanashi, Tokyo.

The coagulation factor IX/factor X-binding protein (IX/X-bp) from the venom of Trimeresurus flavoviridis is a heterogeneous two-chain protein, and the structure of each chain is similar to that of the carbohydrate-recognition domain of C-type lectins, such as asialoglycoprotein receptors, pancreatic stone protein, and the Fc epsilon receptor for immunoglobulin E. Analysis of the binding properties of IX/X-bp revealed that it binds to the gamma-carboxyglutamic acid (Gla)-containing domains of factors IX and X [Atoda, H. et al. (1994) Eur. J. Biochem. 224, 703-708]. In the present study, we isolated another anticoagulant protein that binds to factor IX but is not to factor X. This protein, designated IX-bp, inhibited factor IXa-induced clotting but not factor Xa-induced clotting, whereas IX/X-bp inhibits both. The concentration of IX-bp for half-maximal binding to solid-phase bovine factor IX was 0.4 nM whereas IX-bp did not bind to factor X even at 40 nM. The binding of IX-bp to solid-phase factor IX was inhibited by the addition of Gla-domain peptide of factor IX, indicating that IX-bp binds to the Gla-domain region of factor IX. IX-bp had two Ca(2+)-binding sites with different affinities for Ca2+ ions. At pH 7.5, the apparent Kd values for these sites were 14 and 130 microM, respectively. IX-bp was a two-chain protein (27.5-kDa band before reduction and 16.8- and 15.7-kDa bands after reduction on SDS-PAGE) and it reacted with immunoglobulin G against IX/X-bp. The complete amino acid sequence of IX-bp was determined. The 16.8-kDa chain (A chain) of IX-bp consisted of 129 residues, of which 19 were different from those in the A chain of IX/X-bp (129 residues). The sequence of the 15.7-kDa chain (B chain) was identical to that of the B chain of IX/X-bp (123 residues). We conclude that IX-bp is a protein that is structurally similar to but functionally different from IX/X-bp. The difference of binding specificity between IX-bp and IX/X-bp presumably arises from the sequence differences in the A chains.

UI	MeSH Term	Description	Entries
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D011956	Receptors, Cell Surface	Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.	Cell Surface Receptor,Cell Surface Receptors,Hormone Receptors, Cell Surface,Receptors, Endogenous Substances,Cell Surface Hormone Receptors,Endogenous Substances Receptors,Receptor, Cell Surface,Surface Receptor, Cell
D003435	Crotalid Venoms	Venoms from snakes of the subfamily Crotalinae or pit vipers, found mostly in the Americas. They include the rattlesnake, cottonmouth, fer-de-lance, bushmaster, and American copperhead. Their venoms contain nontoxic proteins, cardio-, hemo-, cyto-, and neurotoxins, and many enzymes, especially phospholipases A. Many of the toxins have been characterized.	Bothrops Venom,Crotalidae Venoms,Pit Viper Venoms,Rattlesnake Venoms,Crotactin,Crotalid Venom,Crotalin,Crotaline Snake Venom,Crotalotoxin,Crotamin,Pit Viper Venom,Rattlesnake Venom,Snake Venom, Crotaline,Venom, Bothrops,Venom, Crotalid,Venom, Crotaline Snake,Venom, Pit Viper,Venom, Rattlesnake,Venoms, Crotalid,Venoms, Crotalidae,Venoms, Pit Viper,Venoms, Rattlesnake,Viper Venom, Pit
D005170	Factor X	Storage-stable glycoprotein blood coagulation factor that can be activated to factor Xa by both the intrinsic and extrinsic pathways. A deficiency of factor X, sometimes called Stuart-Prower factor deficiency, may lead to a systemic coagulation disorder.	Autoprothrombin III,Coagulation Factor X,Stuart Factor,Stuart-Prower Factor,Blood Coagulation Factor X,Factor 10,Factor Ten,Stuart Prower Factor,Factor X, Coagulation
D005591	Chemical Fractionation	Separation of a mixture in successive stages, each stage removing from the mixture some proportion of one of the substances, for example by differential solubility in water-solvent mixtures. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Fractionation, Chemical,Chemical Fractionations,Fractionations, Chemical
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein