Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: HUMANGGP:021525 (albumin)
 60,984 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The protease isolated jawasee shrub was found to hydrolyze egg albumin, casein, haemoglobin and gelatin optimally near neutral pH. Fibrin, bovin serum albumin, skin albumin and skin mucoids were hydrolyzed at slightly alkaline pH, while skin globulins were hydrolyzed at slightly acidic pH. The enzyme had no effect of fibrous collagen. The optimum conditions for the hydrolysis of 50 mg of egg albumin were found to be 50 mg of alhagain at pH 6.0 and 45 degrees C for 30 minutes. A Km value of 4.4 X 10(-3) M was obtained from the Lineweaver-Burk plot for the hydrolysis of egg albumin. The enzyme was found to be comparatively thermostable and was most stable at pH 4.7. Ultraviolet irradiation exhibited no appreciable effect on the enzyme activity. The ultraviolet absorption spectrum of alhagain in bi-distilled water resembles those of bromelain and trypsin. The sugar-containing enzyme was found to have a molecular weight of 20,650. The enzymeconsists of 189 amino acid residues per molecule, neutral and acidic amino acids being present in high concentrations. The partial specific volume of alhagain was calculated to be 0.743 ml/g from its amino acid composition. Phenylalnine and arginine formed the amino terminal amino acids of alhagain, while aspartic acid and serine were identified as its carboxy terminal amino acids. Results are discussed with relation to other plant proteases.
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PMID:Studies on the physico-chemical properties of alhagain. 2 Nov 47

The Acinetobacter spec collagenase has been almost completely purified. This enzyme is a true collagenase the activity of which is high on collagen. The enzyme is active on insoluble collagen, gelatin and the synthetic Pz-peptide, but has no proteolytic activity on casein or bovine serum-albumin. The collagenase was obtained on a simple medium with gelatin and yeast extract. The enzyme was purified by (NH4)2SO4 precipitation. DEAE cellulose column chromatography, Sephadex G 200 gel-filtration. The molecular weight of the enzyme was found to be 102 000 daltons, and its isoelectric point was found to be 7,7 +/- 0,2. The optimum pH and temperature for insoluble collagen hydrolysis were 7.6 and 37 degrees C, respectively; so, this collagenase corresponds to true collagenase. Hydrolysis of Pz-peptide is activated by Ca2+ and inhibited by metal ions (Cu2+, Fe3+, Zn2+, Pb2+, Hg2+). EDTA and o-phenanthroline induced a very significant reduction in enzyme activity. Iodoacetate and p-CMB induced a slight reduction in enzyme activity only at high concentrations (10-2M). The collagenase is most stable for temperatures less than or equal to 50 degrees C.
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PMID:[Purification and physico-chemical properties of collagenase synthesized by a bacterium of the type Acinetobacter sp]. 4 44

Gel filtration of human platelet-rich plasma (PRP) on columns of Sepharose 2B removed at least 99.85% of the plasma proteins from platelets when a column 10 cm in height was used and a plasma volume 11 to 14% of the gel-bed volume was applied. ADP and ATP levels in gel-filtered platelets (GFP) were not significantly different from those in PRP. By transmission electron microscopy, GFP were indistinguishable from PRP. Gel filtration appears to be a highly satisfactory technique of separating platelets from plasma without modifying structure, function, or contents significantly. The roles of several crude protein fractions in platelet aggregation and aspirin's inhibition of aggregation were examined. Fraction I (mostly fibrinogen) enhanced collagen-induced aggregation of gel-filtered platelets; Fraction V (mostly albumin) was inhibitory. Fraction II (mostly gamma-globulin) or gelatin had no significant effect. Aspirin added to gel-filtered platelets inhibited aggregation by 80%. The addition of mixtures of plasma proteins containing albumin increased albumin's inhibitory effect. Incubation of gel-filtered platelets with aspirin labeled in the carboxyl position resulted in no uptake of the label. In contrast, incubation with acetyl-labeled aspirin was followed by uptake of more than 2 X 10(6) acetyl groups per platelet in 1 minute. Incubation for 30 minutes resulted in a five- to sixfold further increase in uptake of the label. Aspirin can acetylate platelets and inhibit aggregation directly. Plasma proteins, in particular albumin or a contaminant of the albumin fraction tested, enhance the inhibitory effect of aspirin on platelet aggregation.
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PMID:Gel-filtered human platelets. Ultrastructure, function, and role of proteins in inhibition of aggregation by aspirin. 5 50

The interaction of suspensions of washed pig platelets with nine artificial surfaces (glass, polystyrene, three segmented polyurethanes, and surfaces formed by coating glass with albumin, fibrinogen, gamma-globulin, and collagen) is reported. Platelet adhesion and release from adherent platelets were measured via labeling with 51Cr and 14C-serotonin. The apparatus was a couette flow device allowing observation of surface-platelet effects uncomplicated by transport or flow effects. Using a two-level factorial design the effects of albumin, fibrinogen, red cells, and platelet count on adhesion and release were estimated for each surface. Comparison of the various surfaces showed that collagen and gamma-globulin are the most reactive (mean adhesion, 34 platelets/100 micrometer2, mean release 50% of granule contents). The other surfaces showed lower levels of release (approximately 25%), indistinguishable one from another. The adhesion levels of two hydrophilic polyurethanes and albumin were low, while those of the remaining surfaces were moderate. The effect of albumin was to reduce adhesion for the "moderate" group of surfaces. Fibrinogen increased adhesion to nonprotein surfaces and decreased release for collagen and gamma-globulin surfaces. High platelet count increased adhesion to fibrinogen, gamma-globulin, and collagen surfaces. Red cells increased adhesion to all surfaces and increased release for collagen and gamma-globulin.
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PMID:Platelet-foreign surface interactions: release of granule constituents from adherent platelets. 7 73

Hepatocytes from adult rats were maintained in primary culture for up to 10-13 days on nylon meshes coated with a thin layer of rat tail collagen gel. Their ultrastructure closely resembled that of the liver parenchymal cell in vivo, but hepatocytes in late culture exhibited a pronounced buildup of microfilaments beneath their apical cell surface. Hepatocytes in early and late cultures secreted albumin, transferrin, and alpha1-acid glycoprotein into the medium; they exhibited a 7- to 10-fold induction of tyrosine aminotransferase activity by dexamethasone; and they expressed an alkaline phosphatase that was similar to that of normal rat liver with respect to its inhibition by the liver enzyme inhibitor L-homoarginine. In addition, the hepatocytes in culture demonstrated phenotypic changes characteristic of fetal liver parenchymal cells. These changes, which paralleled an increase in DNA synthesis, included the expression of and linear increase in the activity of the fetal liver cell enzyme gamma-glutamyl transpeptidase, an increased production of alpha1-fetoprotein, and a change in the substrate specificity of fructose-bisphosphate aldolase to that of the fetal liver isozyme.
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PMID:Fetal phenotypic expression by adult rat hepatocytes on collagen gel/nylon meshes. 8 1

A number of soluble proteins contained in human aortic intimal tissue was extracted into buffered saline (pH 7.4) and identified and quantitated by immunoelectrophoresis and immunodiffusion. The proteins included IgA, IgG, IgM, B1C (C3), alpha 1-antitrypsin, alpha 2-macroglobulin, fibrinogen, albumin, LDL, HDL, alpha 1-acid glycoprotein, beta 2-glycoprotein, transferrin and ceruloplasmin. The concentration of soluble proteins was significantly higher in the atherosclerotic intima than in the normal intima. The diseased intima also contained a small amount of tissue-bound IgG, IgA and B1C which was extractable with citrate buffer at pH 3.2. The vascular band IgG, and B1C were shown by enzymatic and immunohistochemical studies to be closely associated with the collagenous tissue of the plaque. The Ig contained in the atherosclerotic plaque may be derived in part from the biosynthesis of Ig by the artery, since the incorporation of 14C-labeled leucine into IgG by the atheromatous plaque was demonstrable by radioimmunoelectrophoresis. In contrast to the diseased artery, the normal artery did not synthesize IgG and did not contain vascular bound IgG or complement. However, the normal artery was capable of fixing IgG and B1C eluted from the diseased artery. The present studies suggested that the IgG contained and synthesized by the plaque might represent an immune response to an endogenous or exogenous antigen closely associated with plaque collagen. IgG and B1C either alone or in the form of an immune complex also may play an important role in phagocytosis in the plaque and thereby influence the course of atherosclerosis. The proteolytic inhibitors, alpha 1-antitrypsin and alpha 2-macroglobulin, found in relatively high concentrations in the plaque, could enhance fibrosis of the lesion because of thier known inhibitory effects on collagenase and elastase.
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PMID:Soluble proteins in the human atherosclerotic plaque. With spectral reference to immunoglobulins, C3-complement component, alpha 1-antitrypsin and alpha 2-macroglobulin. 9 93

This study was carried out to evaluate the effects of albumin-bound fatty acids on the anti-platelet effects of endothelial cells. Primary cultures of human endothelial cells (ECM), grown in confluent monolayers, were incubated with plasma or growth medium enriched with albumin-bound fatty acids (FA) for 2-20 h. The effects of ECM on ADP-induced platelet aggregation (PA) and collagen-induced PA and prostaglandin synthesis in platelet-rich plasma were tested. ECM released an inhibitor of platelet reactions which resembled the activity of PGI2 (prostacyclin). The inhibitory activity was increased by preincubation of ECM with arachidonic acid (AA). A moderate decrease of the activity was obtained by incubation with long-chain saturated, monoenoic and dienoic unsaturated fatty acids. A pronounced decrease of the inhibitor was obtained by incubation with di-homo-gamma-linolenic acid (DHLA). Paired combinations of AA with the other fatty acids in the incubation medium partially restored the inhibitory activity obtained by the separate FA. The stimulation of the inhibitor by AA was dose dependent and high concentrations of AA reduced this activity. The present study indicates that the quantity and quality of the plasma free fatty acids can affect the endothelial cells' ability to act as a non-thrombogenic surface.
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PMID:The effects of albumin bound fatty acids on the platelet inhibitory function of human endothelial cells. 11 Jun 1

The aortic content of glycosaminoglycans and collagen as well as the uptake of [125 I] albumin were studied in 53 male albino rabbits during hair-shedding and outside the period of hair-shedding to elucidate the previously reported resistance to experimental arteriosclerosis during the shedding period [1]. The concentration of hyaluronic acid was highest during hair shedding, decreasing towards the non-shedding period. The content of dermatan sulphate, chondroitin-4, 6-sulphate and hydroxyproline was lowest during sheeding and highest outside the sheeding period. Accordingly, the incorportation of [35 S] sulphate in chondroitin -4, 6-sulphate and the dermatan plus heparan sulphate fraction was increased outside shedding, consistent with a stimulated synthesis. The concentration of hyaluronic acid was negatively correlated to the uptake of [125I] albumin, and the dermatan sulphate content was positively correlated to the content of hydroxyproline. The higher concentration of hyaluronic acid during the period of shedding may improve the elastic properties as well as the ability of the aortic wall to absorbe the haemodynamic strain involved in the vascular injury of this type of experimental arteriosclerosis [2]. The decrease in the concentration of hyaluronic acid simultaneously with an increase in the aortic content of collagen as well as of chondroitin-4, 6-sulphate and dermatan sulphate may imply a greater stiffness of the aorta resulting in a higher susceptibility to injury. The relationship between hyaluronic acid and [125 I] albumin is consistent with an importance of hyaluronic acid to the susceptibility of the arterial wall to deposition of macromolecules such as the lipids. Our observations represent an example of endogenous conditioned variations in the aortic content of glycosaminoglycans and hydroxyproline accompanied by a variation in the susceptibility to experimental arteriosclerosis.
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PMID:Seasonal variations in the susceptibility of the aortic wall to atherosclerosis. Biochemical studies of glycosaminoglycans and collagen of rabbit atherosclerosis. 13 91

An improved vascular graft was achieved by treating knitted Dacron prostheses with cross-linked albumin. Eight segments, each six centimeters in length, were coated and implanted in the canine thoracic aorta for periods ranging from 24 hours to six months. The results were compared with the eight untreated grafts implanted for similar periods as control experiments. Albumin coating resulted in a faster healing : cells appeared earlier and collagen development was greater. The most beneficial effect of that treatment was the reduction in embolization, as shown by the considerable decrease in kidney damage.
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PMID:Albuminated dacron protheses as improved blood vessel substitutes. 15 Apr 14

When completely demineralized, the densely packed structure of bone matrix does not recalcify, neither in physiologic solutions in vitro nor in implants in vivo. Even when inorganic and organic calcification inhibitors (which normally are stored in bone matrix) are removed first by autolytic digestion in neutral buffers at 37C and then by sequential chemical extraction, implants of the EDTA insoluble residue will not recalcify after as long as 4 wk in a muscle pouch. However, if first demineralized in cold dilute HCl, second, extracted and autodigested in buffers solution at 37C, and then further extracted in EDTA and other solutions at 2C, a calcification initiator protein (Cp) is unmasked, and the residue will invariable recalcify. CIP, isolated by gel filtration and column chromatography, is a disulfide-bonded glycoprotein aggregate composed of subunites of a moleclar mass of 55,000. CIP is composed of a large proportion of acidic amino acids and has a calcium binding capacity of about 1.8 times greater than albumin. The affinity constant CaCIP, calculated by ultrafiltration of physiologic solutions of Ca2+, is log K, 2.9. Observations on implants of residues that containe a) CIP but not a bone morphogenetic property (BMP), B) BMP accompanied by CIP activity, or c) neither BMP nor CIP activity suggested that BMP covers CIP and that the two are attached to bone collagen in tandem. Whether CIP plays a part in calcification of the normal skeleton requires further investigation.
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PMID:A bone matrix calcification-initiator noncollagenous protein. 19 Sep


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