Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Adult bovine aortic tissue was homogenized in a neutral phosphate buffer containing proteinase inhibitors. The insoluble residue was rehomogenized in Tris-buffered 6 mol/L guanidinium chloride (pH 7.4). An insoluble fibrillar protein, floating above the main pellet after recentrifugation, was harvested. This material agglutinated washed fixed human platelets in the presence of either normal human plasma or purified von Willebrand factor (vWF). No such reaction was seen when either buffer or plasma from patients with severe von Willebrand's disease was added instead. The extent of platelet agglutination was measured photometrically, similarly to the ristocetin cofactor assay. The agglutination reaction was strongest at neutral pH and was impaired after either addition of EDTA or previous digestion of the fibrillar material by collagenase or pepsin. By light microscopy platelets were seen to adhere onto isolated fibers. Amino acid composition, subunit polypeptides, substrate properties, and interaction with fibronectin of this fibrillar protein were comparable to those of collagen. Therefore, we tentatively denote the induction of platelet agglutination by vWF protein in the described test system as "vWF-collagen cofactor" activity. Comparison of this activity in 65 plasma samples, containing various concentrations of vWF, with ristocetin cofactor activity showed good correlation between results obtained in both tests (r = 0.91).
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PMID:Von Willebrand factor-dependent agglutination of washed fixed human platelets by insoluble collagen isolated from bovine aorta. 300 53

Sinusoidal endothelial cells were isolated by collagenase-pronase digestion of rat livers followed by centrifugal elutriation. The main endothelial cell fraction consisted of more than 85% endothelial cells as shown by electron microscopy and enzyme histochemistry. Contamination by Kupffer cells was less than 5%. The endothelial cells formed a coherent stable monolayer on dishes coated with collagen type IV in the presence of an RPMI 1640 medium supplemented with 4% Ultroser. Fc receptors were undetectable immediately after elutriation but reappeared after 12 h in culture. Von Willebrand factor (formerly factor VIII-related antigen) could not be detected unequivocally by immunofluorescence. Unchallenged endothelial cells did not produce eicosanoids. In the presence of free arachidonate, however, prostaglandins D2 and E2 as well as thromboxane B2 and 6-keto-prostaglandin F1 alpha were detected by radioimmunoassay and by high-performance liquid chromatography analysis of [3H]arachidonate-exposed cells. Cells treated with the Ca2+ ionophore A23187 produced the same spectrum of immunologically measured prostanoids. In contrast to Kupffer cells in primary culture, eicosanoid formation by endothelial cells was neither triggered by phagocytotic stimuli nor suppressed by pretreatment with dexamethasone.
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PMID:Rat hepatic sinusoidal endothelial cells in monolayer culture. Biochemical and ultrastructural characteristics. 327 4

Human factor VIII was purified from cryoprecipitate and incubated for up to 24 hours with four neutral proteases of human blood leukocytes, namely, with elastase-like protease (ELP), chymotrypsin-like protease (CLP), collagenase and gelatinase. Electrophoretic patterns showed a reproducible sequence of degradation of factor VIII and of its 230,000 molecular weight subunit by ELP and CLP. Intermediate products were similar but those resulting from exhaustive proteolysis by ELP and CLP differed distinctly from each other. Procoagulant activity of factor VIII was rapidly and completely destroyed by ELP and CLP before visible electrophoretic changes would be detected. No increase in this activity was observed prior to its destruction. Von Willebrand factor (ristocetin cofactor) activity was considerably more resistant to ELP and CLP and declined in rough relation to degradation of highly aggregated forms of factor VIII. ELP and CLP produced a pronounced progressive increase in the Laurell reaction antigen. Normal human plasma showed a high potency to inhibit ELP and CLP. Large doses of these enzymes (300 microgram per ml) produced in the plasma medium only a moderate fall in factor VIII procoagulant activity. Collagenase and gelatinase did neither degrade factor VIII nor change its biological properties.
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PMID:Effects of neutral proteases from human leukocytes on structure and biological properties of human factor VIII. 625 22

Von Willebrand protein is present in the extracellular matrix of endothelial cells where it codistributes with fibronectin and types IV and V collagen. Bacterial collagenase digestion of endothelial cells removed fibrillar collagen, but the pattern of fibronectin and of von Willebrand protein remained undisturbed. Exogenous von Willebrand protein bound to matrices of different cells, whether rich or poor in collagen. von Willebrand protein also decorated the matrix of cells grown in the presence of alpha, alpha'-dipyridyl, a collagen-secretion inhibitor. These results indicate that the presence of von Willebrand protein in the extracellular matrix of endothelial cells and the binding of von Willebrand protein to foreign matrices do not depend on the matrix collagen.
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PMID:Von Willebrand protein binds to extracellular matrices independently of collagen. 632 Jan 90