Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P15586 (glucosamine)
 9,425 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An hepatic receptor which recognizes and binds specifically to serum glycoproteins bearing terminal, nonreducing N-acetylglucosamine residues has been purified to homogeneity by affinity chromatography from chicken liver. The isolated binding protein has been characterized as a water-soluble glycoprotein in which sialic acid, galactose, mannose, and glucosamine comprise 8% of the total molecule. The binding reaction is a saturable process and is proportional to receptor concentration. Evidence has been adduced to indicate the presence of a single high affinity binding site with a dissociation constant of 1.4 x 10(-9) M. A single subunit has been identified by polyacrylamide gel electrophoresis in sodium dodecyl sulfate with an estimated molecular weight of 26,000. The chemical and physical properties of the avian protein have been evaluated with respect to the analogous hepatic protein, of mammalian origin, which exhibits a binding specificity for galactose-terminal serum glycoproteins.
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PMID:Isolation and characterization of an avian hepatic binding protein specific for N-acetylglucosamine-terminated glycoproteins. 89 26

Treatment of isolated hyphal walls of Mucor mucedo with nitrous acid resulted in the release of two water-soluble polyanions: (a) a glycuronan, containing all the neutral sugars and uronic acid present in the hyphal wall and (b) an inorganic polyphosphate. The glycuronan could also be extracted quantitatively with salt solutions of high ionic strength and partially with a solution of potassium hydroxide. This is presented as evidence that the glycuronan is a genuine constituent of the cell wall, non-covalently bound to glucosamine-containing polymers which are susceptible to depolymerization by nitrous acid. By treatment with acid the glycuronan was partly converted to crystalline poly(glucuronic acid) with the properties of mucoric acid. This strongly suggests that mucoric acid, which can be extracted from the walls of M. mucedo by alkali after acid treatment, is not a genuine wall component but arises by partial acid hydrolysis of the heteropolymeric glycuronan.
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PMID:The hyphal wall of Mucor mucedo. 1. Polyanionic polymers. 92 97

Diets containing tannic acid at the level of 3% of dry matter were fed to rats in order to ascertain the origin of fecal nitrogen and the effect of tannic acid on the intestinal mucosa. At the same time in order to explain the effect of oxidation of tannins, we administered diets containing oxidized tannic acid or tannic acid associated with an antioxidizer (sodium sulfite) at the level of 1% of dry matter. The increased excretion of sialic acid and glucosamine during ingestion of tannic acid indicated that the excess of fecal nitrogen mainly corresponds to the mucus hypersecretion observed by histology. Fecal analysis revealed perturbations in movements of water and ions. The study of the metabolic activity of isolated enterocytes and the activity of some enzymes in a homogenate of these cells showed an inhibition of oxygen consumption and succinic dehydrogenase activity. Addition of reducing agent (sodium sulfite) to the diet had little effect on the action of tannic acid; but previous oxidation of the tannin reduced the effects observed, particularly in the case of fecal nitrogen loss.
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PMID:Tannic acid and oxidized tannic acid on the functional state of rat intestinal epithelium. 92 59

Following ethylene diamine treatment of the cell wall of Rhodotorula rubra, a water soluble fraction has been isolated. This fraction can be resolved into three glycoproteins and one protein. The major part is a glycoprotein, purified to homogeneity which has a molecular weight of 64 000. The glyco-part of this protein contains mannose, glucose and one residue of glucosamine. After pronase treatment, the presence of an ""Asparaginyl-N-acetylglucosamine" linkage is established by the existence of one aspartic acid residue and one glucosamine residue. After permethylation, the initial data give some evidence that the branching points in the molecule were the carbon atoms 3 and (or) 6 of the mannose moiety and that some glucose moieties are bound to the non-reducing terminal end.
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PMID:[Studies on the cell wall of yeast of the genus Rhodotorula. X. Isolation and purification of cell-wall glycoproteins from Rhodotorula rubra (author's transl)]. 94 81

Of the three major macromolecular components of the vitelline membrane of hen's egg, the lowest molecular weight component (previously designated component I) has been studied and its physicochemical properties clarified. The molecular weight of this component is 27,000 and its chemical composition is typical of a glycoprotein, consisting of protein (91%), total hexose (4.4%), hexosamine (glucosamine 2.3%; galactosamine 0.7%), and sialic acid (1.7%). Uronic acid was not found. The molar ratios of the constituent neutral sugars of this glycoprotein (GP-1) are as follows: fucose 3, mannose 5, galactose 5, glucose 1, and xylose 1. The amino acid profile shows a relatively high proportion of hydrophobic amino acids (39%), which may partly account for the insolubility of GP-I in water.
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PMID:Macromolecular components of the vitelline membrane of hen's egg. II. Physicochemical properties of glycoprotein I. 95 59

Lipolysaccharide was isolated from Chromatium vinosum by phenol/water extraction. The lipopolysaccharide is found exclusively in the phenol phase and can be cleaved into a sugar moiety and a lipid A fraction by hydrolysis in 10% acetic acid at 100 degrees C for 3-4 h. The sugar moiety contains the neutral sugars 3-O-methyl-D-ribose, D-ribose, L-arabinose, mannosamine and glucose, and smaller quantities of D-rhamnose, D-glycero-D-manno-heptose (tentatively identified), quinovosamine and 2-keto-3-deoxyoctonate. L-glycero-D-manno-heptose was not detected. The 2-keto-3-deoxyoctonate linkage in C. vinosum lipopolysaccharide is more resistant to acid hydrolysis than that of Escherichia coli. The lipid A fraction contains glucosamine, mannose and the fatty acids of the lipopolysaccharide. The major fatty acid is beta-hydroxymyristic acid, with smaller amounts of lauric and palmitic acids as well as 14-carbon mono-unsaturated fatty acid, also being present. The phosphorus content of the C. vinosum lipopolysaccharide was found to be approximately 0.1%. Erythrocytes sensitized with alkali-treated C. vinosum lipopolysaccharide were agglutinated by antisera prepared against heat-killed cells. Untreated or heat-treated lipopolysaccharide did not sensitize erythrocytes. The lethal toxicity to mice of the C. vinosum lipopolysaccharide is about one-tenth as that from Salmonella abortus equi.
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PMID:Isolation and characterization of the lipopolysaccharide of Chromatium vinosum. 97 62

Thyroid slices were found to incorporate radioactivity from 14C-labeled sugars into the carbohydrate moiety of a polar lipid soluble in chloroform/methanol/water, 10/10/3. This radiolabeled glycolipid was purified by chromatography on DEAE-cellulose and was shown to have as its monosaccharide constituents mannose, glucose, and glucosamine. This compound cloud also be labeled by incubation of thyroid slices with [3H]mevalonic acid or [32P]phosphate as demonstrated by the coincidence of elution profiles upon DEAE-cellulose chromatography. This suggested that the lipid portion of the molecule is a polyprenol derivative and the lipid-saccharide linkage region involves a phosphate bridge. Mild acid hydrolysis of the glycolipid labeled with 14C in its carbohydrate released a neutral oligosaccharide which on the basis of Bio-Gel filtration studies was shown to have a molecular weight of approximately 2,400. This oligosaccharide contained [14C]mannose and [14C]glucose in about the same ratio as that occurring in the intact glycolipid. The oligosaccharide-lipid appeared to be distributed rather widely in thyroid particulate fractions obtained after differential and density gradient centrifugation. Its highest specific activity occurred in fractions rich in endoplasmic reticulum. By means of pulse-chase experiments in slices a relationship was demonstrated between the disappearance of radioactivity from the lipid-bound oligosaccharide and its appearance in protein-bound form. When protein synthesis was inhibited by the addition of puromycin during the chase period of the experiment transfer of oligosaccharide from the lipid to protein appeared to be blocked and the level of radiolabeled oligosaccharide-lipid increased. The observation that mannose and glucose were similarly affected during the pulse-chase studies suggests that transfer of the intact oligosaccharide unit was involved in the addition of carbohydrate to protein.
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PMID:Lipid-saccharide intermediates in glycoprotein biosynthesis. I. Formation of an oligosaccharide-lipid by thyroid slices and evaluation of its role in protein glycosylation. 97 78

Structural studies have been performed on an oligosaccharide-lipid from thyroid believed to be an intermediate in glycoprotein synthesis. For these investigations the compound was isolated from the gland in unlabeled form as well as differentially radiolabeled in its saccharide, lipid, and phosphate portions by incubation of slices with [14C]- or [3H]glucose, [3H]mevalonic acid and [32P]phosphate, respectively. The unlabeled oligosaccharide-lipid was obtained in a chloroform/methanol/water (10/10/3) extract in a yield of about 1 nmol/g of thyroid and was purified therefrom by DEAE-cellulose chromatography. The saccharide moiety released from the glycolipid by mild acid hydrolysis was isolated by gel filtration and contained 11 mannose, 1 to 2 glucose, and 2 N-acetylglucosamine residues. The reducing terminal position of the oligosaccharide was occupied by 1 of the glucosamine residues and from these analyses a molecular weight of 2,415 was calculated. That glucose is an integral part of the molecule was further demonstrated by the finding that during Dowex 50 chromatography it remained as a constituent of the positively charged oligosaccharide produced by deacetylation with alkaline borohydride at 80 degrees. The phosphorus content of the purified unlabeled oligosaccharide-lipid was determined to be 2 residues per molecule, suggesting the presence of a pyrophosphate bridge between its carbohydrate and lipid portions. Further evidence for such a linkage region was provided by characterization of the products from mild acid and alkaline hydrolysis of the differentially radiolabeled glycolipid. These included dolichyl mono- and pyrophosphate, oligosaccharide phosphate, and free oligosaccharide. Digestion with alpha-mannosidase of the radiolabeled glycolipid led to the release of 39% of its mannose while from the free oligosaccharide 53% of this sugar was removed. Acetolysis of the [14C]oligosaccharide yielded a mannobiose and mannotriose as well as larger fragments consisting of mannose, glucose, and glucosamine. Smith periodate degradation gave rise to a small core segment (6 glycose residues) made up only of mannose and glucosamine from which half of the mannose residues could be released by alpha-mannosidase digestion. From these studies a tentative structure for the carbohydrate moiety of the oligosaccharide-lipid has been proposed. In this formulation an inner core (periodate-resistant) made up of 4 mannose and 2 N-acetylglucosamine residues is attached to the pyrophosphate group by the most internal glucosamine. This core, as well as an additional mannose and 1 to 2 glucose residues, constitutes the alpha-mannosidase-resistant fragment. More peripherally are found other mannose residues, all in alpha-linkage. In this structural scheme the glucose is located so as to prevent the enzymatic release of more internally situated alpha-linked mannose residues.
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PMID:Lipid-saccharide intermediates in glycoprotein biosynthesis. II. Studies on the structure of an oligosaccharide-lipid from thyroid. 97 79

The chemical properties and the general biological activities of lipopolysaccharide (LPS) and Boivin-type endotoxin obtained respectively by phenol-water and trichloroacetic acid extraction from Yersinia enterocolitica serotypes O3 and O9 were studied. The yield of LPS from the O9 strain was about 10% of the O3 strain possibly because of the lower solubility of O9-LPS in aqueous phase. However, the chemical composition of O9-LPS was similar to that of O3-LPS in the proportions of reducing sugar, glucosamine, heptose, KDO, and lipid A. In pyrogenicity and local Shwartzman reactivity in rabbits and lethality for mice, there was also no difference between O3 and O9-LPS. The anthrone-positive carbohydrate and lipid A contents of Boivin-type endotoxin from O3 were higher than those of the endotoxin from O9. The biological activities of Boivin-type endotoxin from O3 were also remarkably higher than those of the endotoxin from O9. It seems that endotoxin of Y. enterocolitica serotype O3 may play an important role in infection by this organism.
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PMID:Biological activities of endotoxins from Yersinia enterocolitica. 97 37

A blood group A active substance was isolated from an acetone-dried powder of oyster viscera by extraction with 0.1 M NaCl after heating a homogenate with extraction medium, in boiling water. After the removal of the acidic fraction with cetylpyridinium chloride, the separated neutral fraction was digested successively with alpha-amylase and amyloglucosidase to remove glycogen. The blood group A-active portion was eluted from a Sepharose 4B column and purified by DEAE-Sephadex column chromatography. The purified active substance was homogeneous by polyacrylamide gel electrophoresis, and its molecular weight was estimated as 100 000 by sedimentation equilibrium. The sugar content of the purified active substance, expressed in percentage of dry weight, was galactosamine, 16.6; galactose, 12.5; fucose, 9.9; glucosamine, 4.6; and glucose, 3.3. Sialic acid was not detected. Total amino acid content was 23.0% and the main constituents were threonine, proline and serine. The ORD spectrum indicated that the hexosamines were N-acetylated. Absence of glycolipid was confirmed by the analysis of fatty acid and sphingosine base. This active substance had a strong blood group A activity (0.04 mug/ml) but neither B nor H activity; it interacted with lima bean lectin but not with concanavalin A.
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PMID:Purification and properties of blood group A-active glycoprotein from oyster viscera. 99 62


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