Biomaterial Database

Characterization of the protein C activator Protac from the venom of the southern copperhead (Agkistrodon contortrix) snake. 1987

K Stocker, and H Fischer, and J Meier, and M Brogli, and L Svendsen

A single chain glycopeptide with a molecular weight of approximately 37,000, an isoelectric point of 3.0 +/- 0.2 and a carbohydrate content of approximately 20% was isolated from the venom of the southern copperhead Agkistrodon contortrix contortrix. It was capable of converting zymogen protein C in plasma of man and various vertebrates into its activated form, a serine proteinase which exerts an anticoagulant effect. Conversion of the zymogen protein C into the active proteinase was demonstrated by measuring the prolongation of the activated partial thromboplastin time due to proteolytic degradation of factors Va and VIIIa by the activation product, as well as by direct measurement of the generated enzyme activity by means of a synthetic chromogenic substrate. Intravenous injection of the venom protein C activator into rabbits caused prolonged activated partial thromboplastin time. Repeated subcutaneous injections led to formation of an antibody which formed, with purified protein C activator as well as with crude A. contortrix venom, a precipitating complex devoid of protein C activator potency. As revealed by activity measurements and by immunodiffusion experiments, the venoms of various A. contortrix, A. bilineatus subspecies contain similar protein C activators.

UI	MeSH Term	Description	Entries
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D009994	Osmolar Concentration	The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent.	Ionic Strength,Osmolality,Osmolarity,Concentration, Osmolar,Concentrations, Osmolar,Ionic Strengths,Osmolalities,Osmolar Concentrations,Osmolarities,Strength, Ionic,Strengths, Ionic
D010455	Peptides	Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are considered to be larger versions of peptides that can form into complex structures such as ENZYMES and RECEPTORS.	Peptide,Polypeptide,Polypeptides
D011480	Protease Inhibitors	Compounds which inhibit or antagonize biosynthesis or actions of proteases (ENDOPEPTIDASES).	Antiprotease,Endopeptidase Inhibitor,Endopeptidase Inhibitors,Peptidase Inhibitor,Peptidase Inhibitors,Peptide Hydrolase Inhibitor,Peptide Hydrolase Inhibitors,Peptide Peptidohydrolase Inhibitor,Peptide Peptidohydrolase Inhibitors,Protease Antagonist,Protease Antagonists,Antiproteases,Protease Inhibitor,Antagonist, Protease,Antagonists, Protease,Hydrolase Inhibitor, Peptide,Hydrolase Inhibitors, Peptide,Inhibitor, Endopeptidase,Inhibitor, Peptidase,Inhibitor, Peptide Hydrolase,Inhibitor, Peptide Peptidohydrolase,Inhibitor, Protease,Inhibitors, Endopeptidase,Inhibitors, Peptidase,Inhibitors, Peptide Hydrolase,Inhibitors, Peptide Peptidohydrolase,Inhibitors, Protease,Peptidohydrolase Inhibitor, Peptide,Peptidohydrolase Inhibitors, Peptide
D011486	Protein C	A vitamin-K dependent zymogen present in the blood, which, upon activation by thrombin and thrombomodulin exerts anticoagulant properties by inactivating factors Va and VIIIa at the rate-limiting steps of thrombin formation.
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
D004305	Dose-Response Relationship, Drug	The relationship between the dose of an administered drug and the response of the organism to the drug.	Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D036341	Intercellular Signaling Peptides and Proteins	Regulatory proteins and peptides that are signaling molecules involved in the process of PARACRINE COMMUNICATION. They are generally considered factors that are expressed by one cell and are responded to by receptors on another nearby cell. They are distinguished from HORMONES in that their actions are local rather than distal.	Growth Factor,Growth Factors,Paracrine Peptide Factors,Paracrine Protein Factors,Factor, Growth,Factors, Growth,Peptide Factors, Paracrine