Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.5 (thrombin)
 33,306 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rabbit platelets were labeled in vivo with 35S for characterization of platelet sulfated glycosaminoglycan. When rabbit platelets were aggregated by ADP, sulfated proteoglycan was lost from the platelet surface although no release of granule contents occurred. The sulfated proteoglycan contained in the granules of platelets pretreated with ADP was subsequently released by treatment with thrombin. The 35S-labeled proteoglycan from both sources was isolated by gel filtration and the glycosaminoglycan portion of the proteoglycan was characterized as chondroitin 4-sulfate by examining the products of digestion with hyaluronidase, chondroitinase AC and ABC, and chondro-4- and 6-sulfatases; by identification of the hexosamine as N-acetylgalactosamine; by determination of a 1 : 1 : 1 molar ratio of N-acetylgalactosamine, uronic acid and inorganic sulfate; and by cetylpyridinium chloride cellulose chromatography. In these studies, the use of 35S-labeled proteoglycan made possible detection and quantification of much smaller amounts of material than would be possible with unlabeled material. Chondroitin 4-sulfate was the only sulfated glycosaminoglycan identified in the proteoglycan lost from the platelet surface during ADP-induced aggregation and in the proteoglycan released from the granules when the platelets were exposed to thrombin.
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PMID:Characterization of the sulfated glycosaminoglycan on the surface and in the storage granules of rabbit platelets. 44 61

Some biological and neurochemical properties of the venom of stonefish (Syanceja horrida) were investigated. The venom exhibited oedema-inducing, haemolytic, hyaluronidase, thrombin-like, alkaline phosphomonoesterase, 5' nucleotidase, acetylcholinesterase, phosphodiesterase, arginine esterase, and arginine amidase activities. Recalcification clotting time, prothrombin, and kaolin-cephalin clotting times were increased 1.7-2.3- and 2.4-fold respectively. The LD50 (i.v. mouse) was 300 micrograms/Kg. Its effects on uptake and stimulation of neurotransmitter synthesis and release were observed in rat brain synaptosomes. In the presence of 100 micrograms venom, uptake of [methyl-3H] choline in rat brain synaptosomes was inhibited 70%, while that of 4-amino-n-[U-14C] butyric acid was inhibited 20%. The toxin also stimulated the release of [3H]-acetylcholine from the synaptosomes.
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PMID:Biological activities of Synanceja horrida (stonefish) venom. 136 68

1. The biological properties of nine venom samples from six taxa of Micrurus were investigated. The venoms exhibited low protease, phosphodiesterase and 5'-nucleotidase activities, moderate to strong phospholipase A and hyaluronidase activities, variable L-amino acid oxidase activity and were devoid of arginine ester hydrolase and thrombin-like activities. Some venom samples exhibited strong acetylcholinesterase activity. Venoms of M. c. dumerili and M. frontalis exhibited exceptionally high alkaline phosphomonoesterase activity while two of the M. f. fulvius venom samples tested exhibited strong hemorrhagic activity in mice. 2. The polyacrylamide gel electrophoretic patterns of the venoms indicate that most of the Micrurus venom proteins are basic proteins. All Micrurus venoms tested exhibited similar SDS-polyacrylamide gel electrophoretic patterns, with an intense low mol. wt protein band. 3. The Micrurus venoms appear to exhibit biological properties similar to other elapid venoms found in Asia and Africa. There are, however, no common characteristics in the biological properties of the venoms examined at the generic level.
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PMID:The biological properties of venoms of some American coral snakes (Genus micrurus). 158 85

1. The hemorrhagic, procoagulant, anticoagulant, protease, arginine ester hydrolase, phosphodiesterase, alkaline phosphomonoesterase, 5'-nucleotidase, hyaluronidase, phospholipase A and L-amino acid oxidase activities of 50 venom samples from 20 taxa of rattlesnake (genera Crotalus and Sistrurus) were examined. 2. The results show that notwithstanding individual variations in the biological activities of Crotalus venoms and the wide ranges of certain biological activities observed, there are some common characteristics at the genus and species levels. 3. The differences in biological activities of the venoms compared can be used for differentiation of the species. Particularly useful for this purpose are the thrombin-like enzyme, protease, arginine ester hydrolase, hemorrhagic and phospholipase A activities and kaolin-cephalin clotting time measurements.
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PMID:A comparative study of the biological activities of rattlesnake (genera Crotalus and Sistrurus) venoms. 167 59

The venom from Crotalus molossus nigrescens contains many activities including: hyde powder azure proteinase; N-benzoyl-arginine-ethyl-ester hydrolase; phospholipase; phosphodiesterase; desoxyribonuclease; fibrinogen coagulase; collagenase, fibrinolytic activity, and hemorrhagic factors. The venom, assayed with amounts of venom up to 50 micrograms protein per assay, does not contain acetylcholinesterase, phosphatase, amylase, ribonuclease, tyrosyl-ester hydrolase or hyaluronidase activities. The venom is lethal to mice with an i.p. LD50 of 2.35 mg/kg mouse. Fractionation of soluble venom by Sephadex G-75 separates at least five families of components. Fractions I-III contains all the enzymes, and fraction V have six small peptides. Further separation of fractions II-III on diethyl-amino-ethyl-cellulose columns at pH 8.0 and 8.3 gave pure proteinase E with a mol. wt of 21,390 and the following N-terminal amino acid sequence; Phe-Ala-Lys-Arg-Tyr-Val-Glx-Leu-Val-Ile-Val-Ala. A thrombin-like enzyme with a mol. wt of 75,000 was also purified from this venom by means of affinity and ion exchange chromatographies.
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PMID:Characterization of the venom from Crotalus molossus nigrescens Gloyd (black tail rattlesnake): isolation of two proteases. 218 98

1. The lethalities, anticoagulant effects, hermorrhagic, thrombin-like enzyme, hyaluronidase, protease, arginine ester hydrolase, 5'-nucleotidase, L-amino acid oxidase, alkaline phosphomonoesterase, phosphodiesterase and phospholipase A activities of twenty-three samples of venoms from twelve species of Asian lance-headed pit vipers (genus Trimeresurus) were examined. 2. The results indicate that notwithstanding individual variations in venom properties, the differences in biological properties of the Trimeresurus venoms can be used for the differentiation of venoms from different species of Trimeresurus. 3. The results also suggest that differences in the biological properties of snake venoms are useful parameters in the classification of snake species. 4. Our results indicate that venoms from the species T. okinavensis exhibited biological properties markedly different from other Trimeresurus venoms examined. This observation supports the recently proposed reclassification of T. okinavensis as a member of the genus Ovophis, rather than the genus Trimeresurus.
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PMID:A comparative study of the enzymatic and toxic properties of venoms of the Asian lance-headed pit viper (Genus Trimeresurus). 255 29

The endothelium of the rabbit thoracic aorta was removed from the vessel wall by one of two procedures, and the freshly exposed subendothelial surface was used for 125I-antithrombin III binding studies. Pretreatment of the subendothelium with either heparitinase or thrombin diminished the uptake of 125I-antithrombin III by up to 80%, whereas pretreatment with plasmin, hyaluronidase or FPR thrombin had little effect. Morphometric analysis of the subendothelium from enzyme-treated and -untreated tissues showed that, whereas plasmin, thrombin and heparitinase each caused a dramatic reduction of the large proteoglycan granules of the extracellular matrix, only exposure to heparitinase and thrombin caused a reduction in the small proteoglycans which populate the basement membrane of smooth muscle cells. Of the subendothelium-bound 125I-antithrombin III, more than 80% was efficiently removed by excess thrombin or by excess heparin. Evidence was obtained for the formation of high molecular weight thrombin-antithrombin III complexes. We conclude that antithrombin III binds largely to proteoheparan sulphate located in the basement membrane of the intimal smooth muscle cells for the purpose of inactivating certain proteases which arise during haemostatic change.
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PMID:Evidence that rabbit 125I-antithrombin III binds to proteoheparan sulphate at the subendothelium of the rabbit aorta in vitro. 333 2

Classical techniques for studying modulations of microvascular permeability have a time resolution of minutes. A newly developed method allows continuous measurement of the electrical resistance of the microvascular membrane in vivo (Olesen & Crone 1983). The technique exploits microelectrodes impaled into the vascular lumen and is based on cable analysis of the vessel. It was applied to venules on the surface of the frog brain to test the effect on microvascular permeability of a wide variety of substances. The following agents increased ionic permeability reversibly within seconds: 5-hydroxytryptamine, bradykinin, ATP, ADP, AMP, phospholipase A2, arachidonic acid, leukotriene C4, oxygen-derived free radicals, ionophore A23187, and unbound Evans blue dye. An irreversible permeability increase was induced by protamine sulphate, neuraminidase, trypsin, melittin, and snake venoms from Crotalus durissus terrificus and Bothrops atrox. The following substances were without effect within an administration period of 5 min: histamine, epinephrine, putrescine, angiotensin II, vasoactive intestinal polypeptide (VIP), substance P, neurotensin, vasopressin, adenosine, PGE2, PGF2 alpha, prostacyclin (PGI2), leukotriene B4, albumin, heparin, plant cytokinins, hyaluronidase, thrombin, wasp venom. Variations in pH between 5.1 and 8.6 did not change permeability. Three conclusions are drawn from the observations: (1) the permeability of cerebral microvessels can be modulated by specific agents, (2) the agents induced changes in the endothelium within a few seconds, and (3) the rapid permeability increase induced by inflammatory mediators was less than two-fold and reversible within minutes.
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PMID:Substances that rapidly augment ionic conductance of endothelium in cerebral venules. 348 16

The effects of a range of commercially available proteases and glycosidases on blastocyst development and hatching were examined on rabbit embryos cultured from the morula stage in a defined medium supplemented with charcoal-treated bovine serum albumin. The proteases tested were trypsin, alpha-chymotrypsin, thrombin, elastase, plasmin, papain, clostripain, collagenase, Streptomyces griseus protease and cathepsin C. The glycosidases tested were neuraminidase, alpha-mannosidase, beta-galactosidase and hyaluronidase. None of these enzymes appeared to stimulate blastocyst growth. The only enzymes which digested the embryonic investments, the zona and mucin coat, sufficiently to cause complete blastocyst hatching were trypsin and Streptomyces griseus protease at relatively low concentrations (250 ng/ml) and chymotrypsin and elastase at higher concentrations.
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PMID:A survey of the effects of proteases and glycosidases on culture of rabbit morulae to blastocysts. 353 6

A protein inhibitor was isolated from commercial preparations of salmon sperm and its physical and anticoagulant properties were compared with an inhibitor isolated earlier from commercial preparation of bovine testicular hyaluronidase. The inhibitor from bovine source was heat and acid labile and had a molecular weight of approximately equal to 35000 while the one from salmon sperm had a molecular weight of approximately equal to 5700 and was stable to heat and acid. To determine the mechanism of the inhibitory effect, a system of purified components consisting of isolated prothrombin, Factor Xa, Factor Va, Ca++, and vesicles of phosphatidylcholine (PCPS, 25% PS) was used. Included also was dansylarginine N- (3-ethyl-1,5-pentanedidyl) amide (DAPA) which binds newly formed thrombin and yields the time course of prothrombin conversion by virtue of enhanced fluorescence of the DAPA - thrombin complex. The inhibitor of bovine testes was effective only when PCPS was the limiting component suggesting that its action was directed against the phospholipid component of the prothrombinase complex. The inhibitor from salmon sperm was found to lower the rate of conversion of prothrombin to thrombin in an in vitro system where thrombin generation was measured by its action on the chromogenic substrate H-D-Phe-Pip-Arg-pNa (S-2238). It inhibited the conversion of Factor X to Xa and also the the amidolytic cleavage by Factor Xa of chromogenic substrate N-Benz-Ile-Glu-Gly-Arg-pNa (S-2222).
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PMID:Mechanism of anticoagulant action by protein inhibitors from bovine testes and salmon sperm. 362 61


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