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:3.4.21.6 (thromboplastin)
13,278 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Known allyl 4,6-O-benzylidene-alpha-D-glucopyranoside was first converted into methyl (prop-1-enyl 2,3-di-O-benzyl-4-O-chloroacetyl-alpha-D-glucopyranosid)-uronate. Acid hydrolysis, followed by treatment with (bromomethylene)dimethyl-ammonium bromide, gave methyl (2,3-di-O-benzyl-4-O-chloroacetyl-alpha-D-glucopyranosyl bromide)uronate. Condensation of this bromide with 3-O-acetyl-1,6-anhydro-2-azido-2-deoxy-4-O-(methyl 2,3-di-O-benzyl-4-O-chloroacetyl-beta-D-glucopyranosyluronate)-bet a-D-glucopyranose. Acetolysis, followed by treatment with titanium tetrabromide, then gave 3,6-di-O-acetyl-2-azido-2-deoxy-4-O-(methyl 2,3-di-O-benzyl-4-O-chloroacetyl-beta-D-glucopyranosyluronate)-alp ha-D-glucopyranosyl bromide. Condensation of this bromide with benzyl 6-O-acetyl-3-O-benzyl-2-benzyloxy- carbonylamino-2-deoxy-4-O-(methyl 2-O-acetyl-3-O-benzyl-alpha-L- idopyranosyluronate)-alpha-D-glucopyranoside provided benzyl O-(methyl 2,3-di-O-benzyl-4-O-chloroacetyl-beta-D-glucopyranosyluronate)-(1- ---4)-O-(3,6-di-O-acetyl- -2-azido-2-deoxy-alpha-D-glucopyranosyl)-(1----4)-O-(methyl 2-O-acetyl-3-O-benzyl-alpha-L-idopyranosyluronate)-(1----4)-6-O-ac etyl-3-O- acetyl-3-O-benzyl-2-benzyloxycarbonylamino-2-deoxy-alpha-D-gluc opyranoside. O-Dechloroacetylation followed by condensation with 6-O-acetyl-2-azido-3,4-di-O-benzyl-2-deoxy-alpha-D-glucopyranosyl bromide provided benzyl O-(6-O-acetyl-2-azido-3,4-di-O-benzyl-2-deoxy-beta-D-glucopyranosyl)- (1----4)-O-(methyl 2,3-di-O-benzyl-beta-D-glucopyranosyluronate)-(1----4)- O-(3,6-di-O-acetyl-2-azido-2-deoxy-alpha-D-glucopyranosyl)-(1----4)-O-(m ethyl 2-O-acetyl-3-O-benzyl-alpha-L-idopyranosyluronate)-(1----4)-6-O-ac etyl-3-O- benzyl-2-benzyloxycarbonylamino-2-deoxy-alpha-D-glucopyranoside in 70% yield. O-Deacetylation followed by re-esterification, O-sulfation, saponification, catalytic hydrogenolysis, and N-sulfation gave the decasodium salt of O-(2-deoxy-2-sulfamido-6-O-sulfo-alpha-D- glucopyranosyl)-(1----4)-O-(beta-D-glucopyranosyluronic acid)-(1----4)-O-(2-deoxy-2-sulfamido-3,6-di-O-sulfo-alpha-D-gl ucopyranosyl)-(1----4)-O-(2-O-sulfo-alpha-L-idopyranosyluronic+ ++ acid)-(1----4)-2-deoxy-2-sulfamido-6-O-sulfo-D-glucopyranose. This synthetic pentasaccharide binds to antithrombin III with an association constant similar to that of high-affinity heparin and elicits a potent anti-factor Xa activity in plasma.
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PMID:Synthesis of heparin fragments. A chemical synthesis of the pentasaccharide O-(2-deoxy-2-sulfamido-6-O-sulfo-alpha-D-glucopyranosyl)-(1-4 )-O-(beta-D-glucopyranosyluronic acid)-(1-4)-O-(2-deoxy-2-sulfamido-3,6-di-O-sulfo-alpha-D-glu copyranosyl)-(1-4)-O-(2-O-sulfo-alpha-L-idopyranosyluronic acid)-(1-4)-2-deoxy-2-sulfamido-6-O-sulfo-D-glucopyranose decasodium salt, a heparin fragment having high affinity for antithrombin III. 370 27

Changes with time in the anti-factor Xa activity of several heparins were determined in freshly autoclaved and unautoclaved dextrose solutions. In the former, activity was raised, in the latter a reversible fall occurred at certain heparin concentrations, and the term "dextrose effect' is applied to the difference in activity in the two types of dextrose solutions. A simple dependence on heparin concentration for the rise in activity in autoclaved dextrose solutions contrasted with a threshold heparin concentration in the unautoclaved dextrose solutions. Above this a fall and below it a rise in activity were demonstrated with one factor Xa method. The pH of the two dextrose solutions differed by one unit but pH was not the principal factor in the effect; salt tended to eliminate the dextrose effect which was found mostly with the high and to some extent also with the low molecular weight fractions of pharmacopoeial heparin. There was no evidence for heparin degradation but activity changes, which differed for different heparins, are thought to be associated with the effects of heparin-dextrose interaction modified in the case of autoclaved dextrose by by-products of autoclaving. Generally, proprietary dextrose solutions gave variable results.
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PMID:The anticoagulant activity of heparins in dextrose solutions. 612 87

Larchwood xylan was purified by diaminoethylaminoethyl (DEAE) cellulose chromatography, sulfated by heating with chlorosulfonic acid -pyridine complex and the sulfated polysaccharide was isolated by epichlorohydrin triethanolamine (ECTEOLA) cellulose chromatography as the sodium salt. It's molecular weight was approximately 25000 and the specific rotation was [alpha]D 20-70 degrees. Electrophoretic analysis of the sulfated xylan along with heparin and SP-54 using lithium acetate-agarose technique showed that the charge density of the xylan sulfate was similar to heparin and it moved as a single component in contrast to commercial heparin which resolved into two while SP-54 moved at the same rate as the marker dye. Anticoagulant properties of the sulfated xylan were compared with heparin and SP-54 by studying its effect on the activated partial thromboplastin time (APTT), prothrombin time (PT) and the thrombin time (TT) using pooled normal human plasma. The sulfated xylan was more effective than SP-54 in delaying coagulation by all the three measurements while it was less active than heparin in inhibiting APTT and PT.
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PMID:Isolation and anticoagulant properties of a new sulfated xylan: comparison with heparin and a sodium pentosan polysulfate (SP-54). 619 1

The interactions of factor V and factor Va light chain with phospholipid vesicles were compared. The results showed that the factor Va light chain bound with the same parameters as factor V when the proteins were present at similar densities on the membrane. The protein-vesicle collisional efficiency was 30-50% for both factor V and factor Va light chain. The factor Va light chain bound at a higher density, and the additional binding interactions had lower affinity. The dissociation process showed negative cooperativity, possibly due to competition for acidic phospholipids in the membrane. The higher molar packing density produced more rapid protein-membrane dissociation rate constants. However, when factor V and Va light chains were present at similar molar densities on the vesicle, the dissociation rates, estimated by two methods, were similar. Analysis of dissociation rates also showed that factor Va interacted with factor Xa on the membrane surface while factor Va light chain did not. Factor Va generated by thrombin digestion of factor V did not result in a major loss of membrane-bound protein mass unless ethylenenediaminetetraacetic acid was present; in the latter case the mass changes indicated that all peptides were removed from the membrane except factor Va light chain. Equilibrium and dynamic measurements showed that ionic strength had a major effect on the dissociation rate but not on the association process. The salt effect indicated interaction between oppositely charged species with the product of the number of charges equal to at least -5.5. Factor Va light chain appeared to interact with phospholipids via a general charge interaction rather than via a specific charge stoichiometry.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Membrane binding properties of blood coagulation Factor V and derived peptides. 644 98

The selective antimetastatic agents p-(3,3-dimethyl-1-triazeno)benzoic acid potassium salt (DM-COOK), 5-(3,3-dimethyl-1-triazeno)imidazole-4-carboxamide (DTIC) and (+/-)1,2-di(3,5-dioxopiperazin-1-yl)propane (ICRF-159) have been shown to markedly depress the formation of spontaneous hematogenous metastases in mice bearing s.c. Lewis lung carcinoma, with a mechanism unrelated to cytotoxicity for tumor cells. The effects on hemostasis of DM-COOK, DTIC and ICRF-159 have thus been examined in comparison with those of a purely cytotoxic agent, cyclophosphamide, in mice bearing i.m. Lewis lung carcinoma. The parameters considered are the number of platelets and their aggregability, prothrombin and partial thromboplastin times, plasma fibrinogen concentration and tumor cell procoagulant activity. Slight variations are caused by drug treatment in tumor-bearing mice as compared with untreated tumor-bearing controls; the pattern of effects of the selective antimetastatic agents does not differ from that of the reference cytotoxic compound used, cyclophosphamide. These data thus indicate that the effects on hemostasis of the drugs examined can contribute only marginally to their antimetastatic action, since more pronounced effects on hemostasis have been shown to be required to significantly affect metastasis formation.
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PMID:Hemostasis and mechanism of action of selective antimetastatic drugs in mice bearing Lewis lung carcinoma. 654 Jan 95

Previous studies showed that the random addition of supplemental albumin to a resuscitation regimen of blood, salt, and frozen plasma caused a significant (p = less than 0.05) fall in fibrinogen clotting activity (FC) and a rise in prothrombin times (PT) in seriously injured patients; the partial thromboplastin times (PTT) were insignificantly prolonged. Based upon these findings, frozen plasma samples, prospectively collected in 41 non-albumin patients and 35 albumin patients, were analyzed immunologically, in duplicate, for protein content of coagulation factor VIII (VIIIAg), prothrombin (IIAg), fibrinogen (FAg), antithrombin III (ATAg), and fibrin(ogen) split products (FSP). Supplemental albumin resuscitation was associated with a significant fall in FAg (83 +/- 9 versus 124 +/- 10 SE mg/dl), VIIIAg (97 +/- 13 versus 127 +/- 135 SE %), IIAg (54 +/- 3 versus 80 +/- 4 SE %), and ATAg (14 +/- 0.8 +/- 19 +/- 0.8 SE mg%) with no significant changes in FSP. FSP, however, were more than 20 micrograms/ml in 13 of 41 nonalbumin patients versus four of 35 albumin patients (X2 = 4.5, p less than 0.05). Reduced coagulation activity following albumin supplementation seems partly caused by a decrease of coagulation protein content; increased fibrinolysis in the albumin patients is not the cause. Decreased coagulation protein content parallels the fall in coagulation activity and the need for postresuscitation blood transfusions. The role of reduced coagulation synthesis in these changes needs further study.
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PMID:Altered coagulation protein content after albumin resuscitation. 680 24

Disseminated intravascular coagulation (DIC) is a common occurrence during clinical sepsis and can be induced in the experimental host by LPS. Fibrin deposition in the hepatic microcirculation has been observed within 30 min of i.v. injection of LPS. Because mononuclear phagocytes have been shown to produce a PCA after exposure to LPS, we have examined the ability of a homogeneous population of explanted hepatic macrophages to express PCA. Addition of as little as 10 ng/ml of LPS stimulated a 15- to 20-fold increase in PCA over control culture levels within 7 1/2 hr post-treatment. The PCA was found to be membrane-associated, with approximately 90 to 95% of the total PCA present in the cellular lysates, and more than 85% was inhibited by pretreatment of the cells with the diazonium salt of sulfanilic acid, an inhibitor of ecto-enzymes. In contrast to tissue thromboplastin produced by other M phi populations, the H-M phi PCA was found to be markedly sensitive both to heat inactivation at 56 degrees C and to inhibition by 1 mM DFP. Additionally, assays involving both a 1-stage coagulation test as well as an enzyme assay with a Factor Xa-specific substrate (using normal and deficient human plasmas) demonstrated that the H-M phi PCA appears to activate Factor X directly. Unlike tissue thromboplastin, the H-M phi PCA is non-dependent of Factor VII activation. These studies: 1) demonstrate the LPS induces a unique PCA in the H-M phi, and 2) support a role for the H-M phi in the initiation of DIC in endotoxemic shock.
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PMID:The induction of a unique procoagulant activity in rabbit hepatic macrophages by bacterial lipopolysaccharides. 702 10

High-density (HDL), low-density (LDL) and very low-density lipoproteins (VLDL) have been purified from normal human plasma by a combination of ultracentrifugation in high-density salt and agarose gel filtration. The ability of these lipoproteins to inhibit different molecular weight heparin fractions has been compared, using incubation mixtures comprised of antithrombin III and factor Xa. Residual factor Xa activity was measured using the chromogenic peptide substrate Bz-Ile-Glu-Gly-Arg-pNA. LDL inhibited the high molecular weight (but not low molecular weight) heparin accelerated neutralisation of factor Xa by antithrombin III. VLDL showed a similar, though much reduced anti-heparin activity, while the addition of HDL to the factor Xa incubation mixture produced no measurable anti-heparin activity. These observations suggest that certain plasma lipoproteins may selectively modulate the inhibitory action of heparin against factor Xa.
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PMID:The anti-heparin properties of human low-density lipoprotein. 718 13

The anticoagulant effect of the sodium and the calcium salts of a new potent heparin was compared in beagle dogs following a single s.c. injection. The determinations of whole-blood clotting time, activated partial thromboplastin time and plasma heparin levels using the amidolytic assay 1, 2, 4, 6, 8, 10 and 12 h post injection revealed that the calcium salt was just slightly more active than the sodium salt of heparin. The influence of the molecular composition in particular the inorganic ion content associated with heparin on the anticoagulation activity achieved after subcutaneous injection, is discussed.
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PMID:Characterization of a new potent heparin. 6th communication: The comparison of the anticoagulant effect of the sodium and calcium salts of a new potent heparin after s.c. injection in beagle dogs. 719 97

A procedure is described for isolation of prethrombin I using biospecific chromatography of the thrombin hydrolysate of prothrombin complex on heparin-Sepharose. The prothrombin complex was activated in 0.05 M Tris-HCl buffer, pH 7.4, containing 0.15 M NaCl, ImM EDTA-Na salt at 37 degrees within 15-20 min; the ratio of the enzyme and substrate was equal to 1 : 1300 (evaluated by the enzymatic activity). Then prethrombin I was isolated by the affinity chromatography. Prethrombin I was specially adsorbed on the immobilized heparin and eluted with 0.45 M NaCl. The substance was free from factor X and alpha-thrombin, which were eluted with 0.64 M and 0.8-1.0 M NaCl, respectively. Fragment I of prothrombin was not adsorbed on heparin-Sepharose and was found in the free volume of column. Preparation of prethrombin I (molecular mass 67,000 +/- 3,000) did not exhibit the coagulating, esterase and prothrombin activities but produced thrombin in presence of factor Xa. The abilities of prethrombin I to interact with blood vessel chemoreceptors and to activate the anticoagulation system were shown, when physiological activity of prethrombin I was studied using perfusion of rabbit carotid sinus, which was insulated from humoral action but retained the nervous connections with a body.
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PMID:[Use of affinity chromatography for isolating prethrombin 1]. 733 61


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