Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.69 (APC)
 16,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Platelet-rich plasma from dogs and from coumadin-treated dogs aggregated at the same optimum concentration of epinephrine. Neither protein C nor its active form called autoprothrombin II-A was necessary for aggregation of dog platelets with epinephrine. For platelet aggregation, suboptimal concentrations of epinephrine were potentiated by addition of purified autoprothrombin II-A. The latter, by itself, induced platelet aggregation in high concentration.
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PMID:Effects of autoprothrombin II-A on epinephrine-induced platelet aggregation of normal- and coumadin-treated dogs. 72 51

Improved methods are described to obtain bovine prothrombin, Factor IX, Protein C, and autoprothrombin III (Factor X, Auto-III) in purified form. The prothrombin had a specific activity of 4,340 Iowa units/mg. Theoretically, a preparation of clean thrombin should have a specific activity of 8,200 U/mg, because 47.08% of the protein in prothrombin is lost when thrombin forms. Such thrombin preparations have been obtained (Arch. Biochem. Biophys. 121, 372 (1967)). The prothrombin concentration of bovine plasma is near 60 mg/liter. Protein C, first isolated by Stenflo (J. Biol. Chem. 251, 355 (1976)), was found to be the precursor of autoprothrombin II-A (Auto-II-A), discovered earlier (Thromb. Diath. Haemorrh. 5, 218 (1960)). Protein C (Factor XIV) was converted to Auto-II-A (Factor XIVa) by thrombin. Digesting purified Auto-III with purified thrombin removed a small glycopeptide from the COOH-terminal end of the heavy chain to yield Auto-IIIm. Auto-III thrombin leads to Auto-IIIm + peptide. Auto-IIIm was not converted to the active enzyme with thromboplastin, and furthermore, inhibited the activation of purified native Auto-III with thromboplastin. Auto-IIIm was also not converted to the active enzymes when the procoagulants consisted of purified Factor VIII, purified Factor IXa, platelet factor 3 and calcium ions. The "activation peptide" released by RVV-X from the NH2-terminal end of the heavy chain and the active enzyme (Auto-Cm) were purified. Auto-III was also activated with purified RVV-X. The same "actid of Auto-Cm. Purified Factor IX developed anticoagulant activity when reacted with an optimum concentration of purified thrombin. A suitable reagent for the assay of Factor IX was prepared by removing prothrombin complex from anticoagulated bovine plasma and restoring the prothrombin and Auto-III concentration with use of the respective purified proenzymes.
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PMID:Improved procedures for the purification of selected vitamin K-dependent proteins. 78 72

Two major proteins, termed proteins A and B, and one minor species, termed protein C, have been purified to homogeneity from dilute acid extracts of dormant spores of Bacillus megaterium. These three species comprise approximately 80% of the protein in the dilute acid extracts and account for 60 to 75% of the protein degraded during spore germination. All three proteins have low molecular weights (7,000 to 10,000), high isoelectric points (greater than 9.8), alanine as the NH2-terminal amino acid, are more hydrophilic than most proteins, and all lack cysteine, cystine, and tryptophan. In addition all three proteins are extremely sensitive to a wide variety of proteolytic enzymes, much more so than "average" proteins such as serum albumin, lysozyme, and hemoglobin. These proteins also bind to both purified DNA and to a nuclear body from dormant spores. Although this binding gives little or no protection to proteins A and B from proteolysis, it does result in elevation of the melting temperature of the DNA by as much as 20degrees.
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PMID:Purification and properties of some unique low molecular weight basic proteins degraded during germination of Bacillus megaterium spores. 80 43

The isolation of a highly purified phosphoprotein, previously named protein C, from human parotid saliva is described. A chemical and physical characterization of protein C was undertaken and the properties of protein C were compared with those of a related protein A. The content of glycine, proline and dicarboxylicamino acids accounts for 83% of the total resideus of protein C and it contains 2.0 mol of P/mol of protein, most likely as phosphoserine. The protein also contains 1.2% glucose, but no hexosamine. The N-terminus is blocked and the proposed C-terminal sequence is -Ser(Gly, Pro)Gln. The molecular weight determined from ultracentrifugation is 16300. Circular dichroism and nuclear magnetic resonance fail to demonstrate the presence of polyproline structure, and there are no conformational changes under a variety of conditions. With specific antisera to protein C the protein can be detected in submandibular as well as in parotid saliva, but there is only reaction of partial identity of proteins A and C. It is proposed that at least part of the difference between proteins A and C is due to the presence of an additional length of peptide at the C-terminus of protein C.
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PMID:Chemical and physical characterization of a phosphoprotein, Protein C, from human saliva and comparison with a related protein A. 86 25

Protein C is a vitamin K dependent protein present in bovine plasma (Stenflo, J. (1976), J. Biol. Chem. 251, 355). It is a glycoprotein (mol wt approximately 62 000) composed of a heavy chain (mol wt 41 000) and a light chain (mol wt 21 000). The heavy chain has an amino-terminal sequence of Asp-Thr-Asn-Gln and contains nearly three-fourths of the carbohydrate. The light chain has an amino-terminal sequence of Ala-Asn-Ser-Phe. Incubation of protein C with either factor X activator from Russell's viper venom or trypsin resulted in the cleavage of an Arg-Ile bond between residues 14 and 15 of the heavy chain. Concomitant with this cleavage was the formation of a serine enzyme which was inhibited by diisopropyl phosphorofluoridate. Liberation of the tetradecapeptide decreased the molecular weight of the heavy chain from about 41 000 to 39 000 and resulted in the formation of a new amino-terminal sequence of Ile-Val-Asp-Gly in the heavy chain. No change in the molecular weight of the light chain was observed during the activation reaction. These results indicate that protein C, like the four vitamin K dependent coagulation proteins, exists in plasma in a precursor form and is converted to a serine protease by hydrolysis of a specific Arg-Ile peptide bond. The biological substrate for the enzymatic form of protein C and the physiological mechanism whereby protein C is converted to a serine enzyme are not known.
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PMID:Proteolytic activation of protein C from bovine plasma. 99 Feb 50

The protease from Russell's viper venom that activates factor X (Stuart factor), factor IX (Christmas factor), and protein C was purified by gel filtration on Sephadex G-150 and QAE-Sephadex A-50 column chromatography. The purified enzyme migrated as a single band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis with an apparent molecular weight of 79 000. A minimal molecular weight of 78 500 +/- 800 was determined by sedimentation equilibrium in the presence of 6 M guanidine hydrochloride. Upon reduction with 2-mercaptoethanol, a heavy chain (mol wt 59 000) and a light chain were observed. The light chain migrated as a single band (mol wt 19 000) in 7.5% polyacrylamide-sodium dodecyl sulfate gels but appeared as a doublet (mol wt 18 000 and 20 000) in 10% polyacrylamide-sodium dodecyl sulfate gels. The amino-terminal end of the heavy chain was heterogeneous and contained isoleucine, valine and serine. The amino-terminal sequence of the light chain was Val-Leu-Asp. The factor X activator contained 13% carbohydrate including 6.0% hexose, 1.7% N-acetyleneuraminic acid, and 5.3% galactosamine. Most of the carbohydrate was found to be present in the heavy chain, although some was also observed in both forms of the light chain. The factor X activator had no esterase activity toward benzoyl-Phe-Val-Arg-p-nitroanilide or benzoylarginine ethyl ester and was not inhibited by 0.05 M diisopropyl phosphorofluoridate. These data indicate that factor X activator from Russell's viper venom is a highly specific protease composed of one heavy chain and one light chain, and these chains are held together by a disulfide bond(s).
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PMID:Factor X activating enzyme from Russell's viper venom: isolation and characterization. 99 Feb 51

The proteins and polysaccharides which are left adherent to the tissue culture substrate after EGTA-mediated removal of normal, virus-transformed, and revertant mouse cells (so-called SAM, or substrate-attached material), and which have been implicated in the cell-substrate adhesion process, have been characterized by SDS-PAGE and other types of analyses under various conditions of cell growth and attachment. The following components have been identified in SAM: 3 size classes of hyaluronate proteoglycans; glycoprotein Co (the LETS glycoprotein); protein Ca (a myosin-like protein); protein Cb(MW 85,000); protein C1 (MW 56,000, which is apparently not tubulin); protein C2 (actin); proteins C3-C5 (histones) which are artifactually bound to the substrate as a result of EGTA-mediated leaching from the cell; and proteins Cc, Cd, Ce, and Cf. The LETS glycoprotein (Co) and Cd appear in newly-synthesized SAM (which is probably enriched in "footpad" material--"footpads" being focal areas of subsurface membraneous contact with the substrate in greater relative quantities than in the SAM accumulated over a long period of time (which is probably enriched in "footprint" material--remnants of footpads left behind as cells move across the substrate). CO and Cd turn over very rapidly following short radiolabeling periods during chase analysis. The SAM's deposited during a wide variety of cellular attachment and growth conditions contained the same components in similar relative proportions. This may indicate well-controlled and coordinate deposition of a cell "surface" complex involving the hyaluronate proteoglycans, the LETS glycoprotein, actin-containing microfilaments with associated proteins, and a limited number of additional proteins in the substrate adhesion site. Evidence indicates that SAM is the remnant of "footpad" vesicles by which the cell adheres to the substrate and that EGTA treatment weakens the subsurface cytoskeleton, allowing these footpad vesicles to be pinched off from the rest of the cell. Three different models of cell-substrate adhesion are presented and discussed.
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PMID:Molecular composition and origin of substrate-attached material from normal and virus-transformed cells. 100 70

1. The initial site of damage in analgesic abuse is the renal medulla and the characteristic lesion is renal papillary necrosis. The papillary necrosis appears to be an ischaemic infarct. The cortical lesion of chronic interstial nephritis is a non-specific change and secondary to obstruction to tubules in the necrotic medulla. 2. Medullary perfusion and the concentration mechanism appear to be important factors in the genesis of renal papillary necrosis. 3. Experimental and clinical studies suggest that abuse of compound analgesics containing aspirin, phenacetin and caffeine result in renal papillary necrosis and the clinical syndrome of analgesic nephropathy. In the APC mixture aspirin appears to be the major nephrotoxic agent while phenacetin plays a synergistic but secondary role in the renal nephrotoxicity.
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PMID:Pathology, aetiology and pathogenesis of analgesic nephropathy. 107 Sep 95

Analgesic nephropathy is part of a wider clinical syndrome associated with the abuse of APC compounds, that is, a minimum total intake of 2 kg of aspirin or phenacetin. Ischaemic heart disease and premature aging are newly recognized aspects of the analgesic syndrome. The diagnosis of analgesic nephropathy can be made precisely by the radiological demonstration of renal papillary necrosis. The most important aspect of management of established analgesic nephropathy and renal insufficency is total avoidance of all non-steroid antiinflammatory agents and this is commonly associated with stabilization or improvement in renal function. In the APC mixture, aspirin appears to be the major nephrotoxic agent while phenacetin and paracetamol play a secondary and synergistic role in the nephrotoxicity.
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PMID:Analgesic nephropathy. 108 2

Reactional leprosy is studied according to its clinical forms A) Lepromatous a) Acute lepromatization: encroaching and invasive nature; the patient becomes more and more lepromatous ; bad prognosis. b) Erythema nodosum: "contusiform dermatitis"; variable prognosis not so bad as it is in the preceding case; allergic nature and its evolution is usually detained and therapeutics efficient. c) Erythema multiform. d) Lucio's phenomenon: vascular lesions and consequently necrosis as a complication of the "erythema necrotisans" (beautiful leprosy). B) Tuberculoid Reactional tuberculoid is the only one in this benign type, the Mitsuda's test must always be positive and prognosis consequently good. C) Dimorphous or "Borderline" whose Mitsuda's test is mostly negative, sometimes positive, but not stable. The lesions may stimulate the tuberculoid leprids but they invade mucous membranes, are impregnated by pigmentation, may present the Unna's band, and other characteristics of the Lepromatous type. Are associated (fever, asthenia and emaciation). Prognosis not very good, because of the possibility of lepromatization, according to its tendency. Evolution slower and frequent relapses. Besides there are nodular lesions. Pathogeny 1) Perifocal allergic reaction (Jadassohn). Similar to epituberculosis and Herxheimer reaction. 2) Septicemia. Sensitized tissues inside or outside the lesions, are invaded by the bacilli and so the allergic reaction takes place. Even without culture resources, Mycobacterium leprae has been found in the blood by direct examination. 3) Autoimmunization (Waldenstrom, Matthews and Trantman, 1965). Based upon the similarity between both humoral syndromes, in leprosy reactions and collagenous, diseases, as to: hypergammaglobulins, hypercryoproteins, antigammaglobulins, serological reactions (Wassermann, Kahn, Kline, VDRL) positives, Antistreptolysin O, protein C reactive, antinuclear factors, latex and Wadler-Rose test positives (rheumatoid tests) lowering of complement. If leprosy reaction is like this, it should be the less agressive of the autoimmune diseases. a) Its eruptions are cyclic not of long standing duration, as a general rule. b) Its prognosis has been recognized as good, except lately, because of the use of corticoid therapy which has been fatal, in many cases. After some years the leprosy reaction cures spontaneously. Treatment (see article)
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PMID:[Reactional status of leprosy]. 124 Oct 72


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