Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.7 (plasmin)
 9,023 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Factor VIII is a large protein molecule of molecular weight 2,000,000 or larger that elutes in the void volume on agarose gel chromatography. It has been shown previously that high concentrations of alkali halides and, more specifically, 0.25 M Ca(2+) dissociate the molecule into a large carrier protein and a small fragment that retains the factor VIII activity. Factor VIII was prepared from normal canine plasma collected in sodium oxalate and heparin and adsorbed with BaSO(4). Results with Ca(2+) dissociation were the same as those obtained with fraction prepared from canine plasma collected in sodium citrate. The addition of 0.1 M epsilon-aminocaproic acid in the dissociation step had no effect. Fractionation of canine hemophilic plasma produced preparations without activity, and no activity was found when these inert preparations were dissociated with Ca(2+). These results indicate that the Ca(2+) dissociation is a true dissociation and not caused by enzymatic degradation by plasmin, thrombin, or activated factors VII, IX, or X. The apparent molecular weight of the small active fragment of factor VIII determined by gel chromatography was about 100,000. Finally, when the large carrier protein and the small active fragment of factor VIII were separated by gel chromatography, mixed, and dialyzed free of Ca(2+), they recombined to form a large active molecule that appeared in the void volume on agarose gel chromatography.
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PMID:Factor VIII recombination after dissociation by CaCl12. 452 67

The in vitro lability of factors V and VIII in plasma has been studied. In agreement with previous reports, an increase in anticoagulant concentration renders both factors more labile (cation-deficient decay), as does an increase in the pH above 7.3 (alkaline-decay). Calcium appears to be the plasma cation which protects factors V and VIII against in vitro loss of activity. The protection obtained by the addition of other divalent cations depended on the type of plasma used. When resin-EDTA plasma was made cation free by dialysis at 4 degrees C and then incubated at 37 degrees C, the rapid loss of factors V and VIII activity could be prevented by prior addition of strontium, manganese and magnesium. In oxalate plasma, nickel, manganese, cadmium and strontium were effective. The alkaline decay of both factors V and VIII is irreversible. Partial reversibility of the cation-deficient decay was demonstrated for factor V, but not for factor VIII. The temperature coefficient for both the cation-deficient and alkaline decay is 2-3, suggesting an enzymatic rather than a physical reaction. There was no evidence to implicate thrombin, plasmin or trypsin since inhibitors of these enzymes failed to modify either type of decay.
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PMID:A study of the cation- and pH-dependent stability of factors V and VIII in plasma. 1695 64

One of the important processes in kidney stone development is crystal invasion through extracellular matrix (ECM). Some proteins in renal tissue or urine have been thought to aggravate crystal invasion. However, this pathogenic mechanism has been previously under-investigated due to a lack of crystal invasion assay. In the present study, we have developed a novel assay for the investigations of calcium oxalate monohydrate (COM) crystal invasion. Matrix gel was loaded into an in-house migration chamber made on a glass slide to simulate the ECM environment. COM crystals were coated with the tested protein, which was then bound with plasminogen. The crystal-protein-(plasminogen) complex and urokinase plasminogen activator (uPA) were placed on-top of the matrix gel. If the tested protein had plasminogen-binding capability, the remaining plasminogen would be activated by uPA to plasmin, which caused crystal migration through the matrix gel. We then applied this novel assay to evaluate effects of some abundant kidney/urine proteins (including purified albumin, carbonic anhydrase, lysozyme and Tamm-Horsfall protein) on COM crystal invasion. The data revealed that albumin, which is the known plasminogen-binding protein, dramatically induced plasmin activity and crystal invasion, whereas other proteins had no significant effects as compared to the control. In summary, we have successfully developed a novel assay for the investigations of crystal invasion based on the plasminogen/plasmin system. This assay is applicable to examine proteins that may serve as potential aggravators of crystal invasion and thus will be very useful for further studies on kidney stone development.
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PMID:A novel assay to evaluate promoting effects of proteins on calcium oxalate crystal invasion through extracellular matrix based on plasminogen/plasmin activity. 2315 18