Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

A difference in recognition of the adhesive glycoprotein vitronectin (also called S-protein, serum spreading factor, and epibolin) by monoclonal antibody 8E6 (Hayman EG, et al, Proc Natl Acad Sci USA 80:4003, 1983) was investigated using a competitive enzyme-immunosorbent assay and immunoaffinity chromatography. Recognition of vitronectin in serum was approximately 50-fold greater than recognition of vitronectin in plasma. Recognition of vitronectin incubated with heparin, thrombin-antithrombin III complex, or heparin and thrombin-antithrombin III complex together was 2.5-, 7-, or 32-fold greater, respectively, than recognition of vitronectin alone. Thrombin or antithrombin III by itself did not induce the antigenic change. Factor Xa-antithrombin III was less effective than thrombin-antithrombin III in induction of the change. Dextran sulfate and fucoidan were more potent than heparin in induction of the antigenic change, whereas dermatan sulfate, hyaluronic acid, heparan sulfate, chondroitin sulfate, or keratan sulfate were less effective. Immunoblotting analysis of serum and of vitronectin incubated with thrombin and antithrombin III demonstrated the presence of complexes composed of vitronectin and thrombin-antithrombin III that could only be dissociated with reducing agent. N-ethylmaleimide completely blocked the formation of the presumably disulfide-bonded complexes and partially blocked the antigenic change. Both non-disulfide-bonded and disulfide-bonded vitronectin bound to antibody-Sepharose from a mixture of vitronectin and thrombin-antithrombin III. Treatment of vitronectin with 8 mol/L urea resulted in enhanced recognition by the monoclonal antibody. Thus, the 8E6 antibody reacts with an epitope that is preferentially expressed by noncovalently and covalently linked vitronectin/thrombin-antithrombin III complexes and by urea-treated vitronectin. The change in vitronectin induced by thrombin-antithrombin III, therefore, is a physiological correlate of urea treatment and of adsorption of vitronectin onto tissue culture plastic (as is done in cell adhesion assays). The change may be important for expression of vitronectin activity.
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PMID:Conformational states of vitronectin: preferential expression of an antigenic epitope when vitronectin is covalently and noncovalently complexed with thrombin-antithrombin III or treated with urea. 245 52

The glycoprotein vitronectin (also called S-protein, serum spreading factor, or epibolin) promotes spreading of a variety of cultured cells, inhibits the cytotoxicity of membrane attack complex C5b-9, and modulates thrombin-antithrombin III activity. We developed a strikingly simple method to purify vitronectin from human plasma by heparin affinity chromatography. Serum was obtained from plasma by adding calcium and then centrifuging. The heparin-binding activity of vitronectin in human serum was activated with 8 M urea. The activated vitronectin specifically bound to heparin-Sepharose in 8 M urea and was eluted with 0.5 M NaCl containing 8 M urea. This procedure resulted in an approximately 250-fold purification of vitronectin with a 15-30% recovery; 3-6 mg of pure vitronectin were obtained from 100 ml human plasma within 2 days. The purified vitronectin preparations promoted spreading of BHK fibroblastic cells on substrates with a half-maximal activity at only 0.1 microgram/ml. This new method is very simple, rapid, inexpensive, and flexible. It could probably be readily scaled up for commercial applications.
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PMID:Novel purification of vitronectin from human plasma by heparin affinity chromatography. 246 Feb 63

A two-step dose-ranging study was undertaken with CY216 (Fraxiparin) in 8 patients on 7 sessions each. The different doses were administered each time as a single bolus injection at the start of hemodialysis without heparinized priming nor further administration during the 4-hour session. In the first step, the clinical efficacy of 4 different doses of Fraxiparin was compared with that of standard heparin on the percentage of sessions free of clot formation in the extracorporeal circulation (ECC). Safety was evaluated by the compression time for hemostasis at the puncture sites. The second step was a randomized comparison of 3 Fraxiparin dosages. In addition to the clinical assessment of efficacy, the following biological parameters were measured: fibrinopeptide A (FPA), anti-Xa (AXa) activity calibrated against Fraxiparin, thrombin time (TT), activated partial thromboplastin time, blood counts, hemoglobin, hematocrit, plasma creatinine and urea, and residual blood volume in the dialyzer. A 'standard' dosage of 10,000 AXa Institut Choay units of Fraxiparin was shown to prevent clot formation in the ECC. It resulted in a marked increase in TT, without any lengthening of the puncture site compression time. After 4 h, AXa and FPA levels in the venous line were related to the doses used (p less than 0.05). After 48 h AXa activity was very low. Dialysance and tolerance were excellent. Thus, a single dose of Fraxiparin unrelated to body weight and not determined by the measurement of the whole-blood activated clotting time appeared to be a safe and effective means for preventing fibrin formation in 4-hour dialysis sessions.
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PMID:Low-molecular-weight heparin Fraxiparin in chronic hemodialysis. A dose-finding study. 255 91

Three major calmodulin-binding cyanogen bromide peptides (fragments A, B, and D) were isolated from chicken gizzard muscle caldesmon and their amino acid sequences were determined. The molecular masses of fragments A, B, and D were estimated to 16, 12, and 9 kDa, respectively, by SDS-urea polyacrylamide gel electrophoresis. Fragment A was composed of 102 amino acid residues and contained homoserine at the C terminus. The amino acid sequence from the 37th residue of fragment A corresponds to the N-terminal sequence of the 15 kDa peptide which was obtained by thrombin digestion [Mornet, D., Audemard, E., & Derancourt, J. (1988) Biochem. Biophys. Res. Commun. 154, 564-571]. Thrombin 15 kDa peptide binds to F-actin but does not bind to calmodulin. Thus the N-terminal 36 residues and the C-terminal part from the 37th residue of fragment A are supposed to bind to calmodulin and F-actin, respectively. The sequences of fragments B and D were identical, but fragment D was composed of 64 amino acid residues and ended with tryptophan, whereas fragment B was of 98 or 99 amino acid residues and ended with proline. Both fragments B and D are supposed to be the C-terminal peptides of chicken caldesmon. Fragment B had heterogeneous sequences at the C-terminal region. These results can explain the reported heterogeneity of chicken caldesmon in charge and molecular mass.
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PMID:Amino acid sequence studies on cyanogen bromide peptides of chicken caldesmon which bind to calmodulin. 261 84

During a recent outbreak of Rhodesian sleeping sickness in the Lambwe Valley no asymptomatic Rhodesian sleeping sickness patients were found although 54% of the primary patients had mild symptoms and 9% were stuporous or comatose at presentation. The duration of symptoms was three months or less in 90% of the patients. Headache, weakness, joint and back pains and weight loss were claimed by at least 75% of the patients, while 82% of the females reported amenorrhoea and 70% of the males claimed impotency. Physical examination revealed lymphadenopathy in 86% but fever in only 36% of the patients, while chancres were found in only 16%. Patients had significantly lower levels of haemoglobin and thrombocytes than controls and their erythrocyte sedimentation rates were elevated. A comparison of both blood group and haemoglobin type between patients and controls yielded no significant differences. Fifty-seven per cent of the primary patients reporting mild symptoms had abnormal levels of leucocytes in their CSF. All relapse patients had abnormal CSF parameters. Levels of serum urea nitrogen were significantly elevated in patients, but SGOT, SGPT and total bilirubin were not. Levels of albumin and beta-globulin in patients were significantly lower than controls while gamma-globulin was elevated. Mean serum IgM levels in patients were elevated to nearly three-fold those of controls, but 35% of the individual patient values fell within the 95% range of control values. Some patients had extended prothrombin and thrombin times while fibrinogen levels were significantly elevated. No patients reported haemorrhage, and none was seen.
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PMID:Presenting features of Rhodesian sleeping sickness patients in the Lambwe Valley, Kenya. 261 98

Human plasma fibronectin (FN) was reduced and carboxamidemethylated, and its binding ability to several matrices was analyzed in vitro. The binding of S-carboxamidemethyl (Cam)-FN to heparin-Sepharose was not influenced by either 4 M urea, 0.5 M NaCl or 0.5% heparin, but was disrupted by the coexistence of urea and NaCl or heparin. S-Cam-FN, compared with intact FN, obviously had a more potent ability to bind heparin, while it had little or no binding ability to gelatin, fibrin and thrombin-stimulated platelets. A conformational change of S-Cam-FN by heparin-binding has been proposed as a possible mechanism from the result of circular dichroic spectrum measurement.
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PMID:Enhancement of heparin-binding ability of fibronectin by S-carboxamide-methylation. 263 Jun 32

Induction of intravascular coagulation and inhibition of fibrinolysis by injection of thrombin and tranexamic acid (AMCA) in the rat gives rise to pulmonary and renal insufficiency resembling that occurring after trauma or sepsis in man. Injection of Captopril (1 mg/kg), an inhibitor of angiotensin converting enzyme (ACE), reduced both pulmonary and renal insufficiency in this rat model. The lung weights were lower and PaO2 was improved in rats given this enzyme-blocking agent. The contents of albumin in the lungs were not changed, indicating that Captopril did not influence the extravasation of protein. Renal damage as reflected by an increase in serum urea and in kidney weight was prevented by Captopril. The amount of fibrin in the kidneys was also considerably lower than in animals which received thrombin and AMCA alone. It is suggested that the effects of Captopril on the lungs may be attributable to a vasodilatory effect due to a reduction in the circulating level of Angiotension II and an increase in prostacyclin (secondary to an increase in bradykinin). Captopril may, by the same mechanism, reduce the increase in glomerular filtration that is known to occur after an injection of thrombin, thereby diminishing the aggregation of fibrin monomers in the glomeruli, with the result that less fibrin will be deposited and thus less kidney damage will be produced.
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PMID:Effects of an inhibitor of angiotensin converting enzyme (Captopril) on pulmonary and renal insufficiency due to intravascular coagulation in the rat. 267 Jul 94

Observations were made of 15 fatal and 35 nonfatal Crimean-Congo hemorrhagic fever (CCHF) infections diagnosed from February 1981 to March 1987 in Kimberly and Sandringham, Republic of South Africa. Following an incubation period of 2-9 days after exposure to infection, patients had a sudden onset of disease with fever, nausea, severe headache, and myalgia. Petechial rash and hemorrhagic signs such as epistaxis, hematemesis, and melena supervened on days 3-6 of illness. Deaths occurred on days 5-14 of illness. Patients with fatal infections had thrombocytopenia and markedly elevated levels of serum aspartate and alanine aminotransaminases, gamma-glutamyltransferase, lactic dehydrogenase, creatine kinase, bilirubin, creatinine, and urea. Total protein, albumin, fibrinogen, and hemoglobin levels were depressed. Values for prothrombin ratio, activated partial thromboplastin time, thrombin time, and fibrin degradation products were grossly elevated, findings that indicate the occurrence of disseminated intravascular coagulopathy. Many of the clinical pathologic changes were evident at an early stage of the disease and had a highly predictive value for fatal outcome of infection. Changes were present but less marked in nonfatal infections.
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PMID:The clinical pathology of Crimean-Congo hemorrhagic fever. 274 11

1. Four clotting factors, Cf-1(C), Cf-2(C), Cf-1(T) and Cf-2(T) were isolated from Agkistrodon acutus (collected on mainland China and Taiwan) venom by Komori et al. (1987). It was reported that all factors possessed coagulant activity in the conversion of fibrinogen to fibrin, although they showed different chemical properties and antigenicities. 2. Their role in the clot formation system was clarified and compared with that of thrombin. Clotting factors from A. acutus venom released only fibrinopeptide A from the A alpha chain of fibrinogen, while thrombin released fibrinopeptide A and B from the A alpha and B beta chains. 3. Cf-1(C) and Cf-2(T), like thrombin, rapidly activated factor XIII in the presence of calcium ions, whereas Cf-2(C) and Cf-1(T) had little effect on factor XIII. These effects are shown by Cf-1(C) and Cf-2(T) forming a clot that remained insoluble in 8 M urea or 0.44 M monochloroacetic acid, whereas Cf-2(C) and Cf-1(T) formed a soluble clot in these agents.
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PMID:Characterization of clotting factors from Agkistrodon acutus venom. 289 11

An additional hydrolysis site recognized by thrombin on histone H1 molecules was found. Snakes venom proteases from Agkistrodon rhodostoma, Bothrops marajoensis and Bothrops moojeni were further used for the analysis of H1 histones. The presence of the main cleavage site on H1 histone molecules has been established. This site is localized on main N-terminal thrombin peptide. The main venom protease peptides obtained from different H1 subfractions preserve differences of electrophoretic mobility in acid-urea polyacrylamide gels typical for the initial H1 subfractions.
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PMID:Comparative enzymatic degradation of H1 subfractions from Syrian hamster tissues. 294 12


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