Thrombocytin, a serine protease from Bothrops atrox venom. 1. Purification and characterization of the enzyme
- Temple Univ. Health Sciences Center, Philadelphia, PA
Thrombocytin, a platelet-activating enzyme from Bothrops atrox venom, has been purified to homogeneity by precipitation with sodium salicylate and chromatography on heparin-agarose. Thrombocytin is a single-chain glycoprotein with a molecular weight of 36,000 which contains 5.6% carbohydrate. It causes platelet aggregation, release of platelet serotonin, and activation of factor XIII. The most sensitive substrate for the amidolytic activity of thrombocytin was Tos-Gly-Pro-Arg-p-nitroanilide hydrochloride. The activity of thrombocytin on this substrate and on platelets was inhibited by diisopropyl fluorophosphate (DFP), soybean trypsin inhibitor, and several arginine chloromethyl ketones. Active site titration with nitrophenyl guanidinobenzoate demonstrated that approximately 86% of the preparation was in the active form. These experiments demonstrate the presence of serine and histidine in the active site of thrombocytin and suggest that thrombocytin is a classical serine protease with a platelet-activating activity similar to thrombin.
- OSTI ID:
- 5424077
- Journal Information:
- Biochemistry; (United States), Vol. 18:16
- Country of Publication:
- United States
- Language:
- English
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PEPTIDE HYDROLASES
ENZYME ACTIVITY
PURIFICATION
VENOMS
BIOLOGICAL PATHWAYS
AGGLOMERATION
AMINO ACIDS
BLOOD PLATELETS
CHROMATOGRAPHY
ELECTROPHORESIS
ENZYME INHIBITORS
EXPERIMENTAL DATA
GLUCOPROTEINS
HISTIDINE
KETONES
MOLECULAR WEIGHT
PRECIPITATION
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ANIMALS
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BODY FLUIDS
CARBOHYDRATES
CARBOXYLIC ACIDS
DATA
DATA FORMS
DRUGS
ENZYMES
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROLASES
HYDROXY ACIDS
HYDROXY COMPOUNDS
IMIDAZOLES
INDOLES
INFORMATION
MATERIALS
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PROTEINS
PYRROLES
RADIOPROTECTIVE SUBSTANCES
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550200* - Biochemistry