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)

It has previously been established that several glycopeptides of peptidoglycan origin are formed as a result of processing of Bacillus subtilis cell walls by the macrophage-like cell line RAW264. Although the formation of these glycopeptides could account for the humoral immune responses characteristic of bacterial peptidoglycans, their formation does not account for the cellular-mediated immune responses observed for water-in-oil emulsions of peptidoglycan or for lipophilic derivatives of glycopeptide fragments thereof. Therefore, the processing of peptidoglycan by macrophages was reexamined to establish whether the lipophilic derivative of any peptidoglycan-derived glycopeptide was formed. The experiments were performed by incubating B. subtilis cell walls radiolabeled in muramic acid, glucosamine, alanine, glutamic acid, and diaminopimelic acid residues in the presence of the macrophage-like cell line RAW264. The crude lipid fraction derived from the macrophages was further fractionated and analyzed, revealing the presence of two lipophilic glycopeptides that contained glucosamine, muramic acid, and alanine of bacterial origin.
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PMID:Incorporation of bacterial peptidoglycan constituents into macrophage lipids during phagocytosis. 257 39

Lipopolysaccharide (LPS) was isolated and purified from Wolinella recta ATCC 33238 by the phenol-water procedure and RNAase treatment. The sugar components of the LPS were rhamnose, mannose, glucose, heptose, 2-keto-3-deoxyoctonate (KDO) (3-deoxy-D-manno-octulosonate) and glucosamine. The degraded polysaccharide prepared from LPS by mild acid hydrolysis was fractionated by Sephadex G-50 gel chromatography into three fractions: (1) a high-molecular-mass fraction, eluting just behind the void volume, consisting of a long chain of rhamnose (22 mols per 3 mols of heptose residue) with attached core oligosaccharide; (2) a core oligosaccharide containing heptose, glucose and KDO, substituted with a short side chain of rhamnose; (3) a low-molecular-mass fraction containing KDO and phosphate. The main fatty acids of the lipid A were C12:0, C14:0, 3-OH-C14:0 and 3-OH-C16:0. The biological activities of the LPS were similar to those of Salmonella typhimurium LPS in activation of the clotting enzyme of Limulus amoebocytes, the Schwartzman reaction and mitogenicity for murine lymphocytes, although all the biological activities of lipid A were lower than those of intact LPS.
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PMID:Chemical and biological properties of lipopolysaccharide, lipid A and degraded polysaccharide from Wolinella recta ATCC 33238. 260 May 85

Carboxyl groups of HbS are readily activated by water-soluble carbodiimide at pH 6.0 and room temperature. These o-acylurea intermediates (activated carboxyl) are accessible for nucleophilic attack by amines. With glycine ethyl ester, the amidation is very selective for the gamma-carboxyl of Glu-43(beta) and more than 65% of the glycine ethyl ester incorporated is on this carboxyl group. In contrast, glucosamine derivatizes the gamma-carboxyl group of Glu-22(beta) as well as that of Glu-43(beta) to nearly the same degree. However, the total amidation of HbS by glucosamine is lower than that with glycine ethyl ester. The differential selectivity of the two amines is apparently related to the differences in the microenvironment of the gamma-carboxyl groups of Glu-22(beta) and Glu-43(beta), which either facilitates or refracts the aminolysis of the activated carboxyl with the two amines to different degrees. The carboxyl groups of isolated beta-chain exhibit a higher reactivity for amidation with glycine ethyl ester than does the tetramer. The carboxyl groups of Glu-22(beta) and Glu-43(beta) and that of Asp-47(beta) are all activated by carbodiimide suggesting that the higher pKa of these carboxyl groups (facilitating the activation) is a property of tertiary interaction of the polypeptide chain. The interaction of the beta-chain with alpha-chain, i.e., generation of the quaternary interactions, reduces overall reactivity of the carboxyl groups of the protein. The higher selectivity of hemoglobin S for amidation at Glu-43(beta) with glycine ethyl ester compared with that of isolated beta-chain appears to be primarily a consequence of decreased amidation at sites other than at Glu-43(beta).
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PMID:Selective amidation of carboxyl groups of the intermolecular contact regions of hemoglobin S: structural aspects. 273 42

We have determined whether changes in lung hyaluronan content affect extravascular water in lungs of unanesthetized rabbits. Three groups of experiments were performed. In group 1 (n = 12), no infusions were given; in group 2, nine pairs of rabbits received either intravenous hyaluronidase (750 U.kg-1.min-1) or an equivalent volume of saline; in group 3, nine pairs of rabbits received either hyaluronidase or saline, followed by intravenous saline infusion amounting to 24% of body weight. At the end of each experiment, one lung was analyzed for extravascular lung water by the wet-dry method. Except for group 3, in all animals the other lung was analyzed for hyaluronan content by a method that involved hydrolyzing lung hyaluronan with fungal hyaluronidase to release reducing N-acetyl glucosamine groups, which were quantified. In group 1, lung hyaluronan, which varied from 50 to 159 micrograms/g dry wt (mean 106 +/- 35 micrograms/g dry wt), significantly correlated with variation in extravascular lung water (mean 4.2 +/- 0.3 g/g dry wt). In group 2 rabbits given hyaluronidase, lung hyaluronan was 40% lower and extravascular lung water was 14.6% lower than in paired controls (P less than 0.01). In group 3, volume expansion did not affect lung water, except after hyaluronidase when lung water was 47% higher than paired controls. We conclude that in the lung the content of hyaluronan is one of the determinants of extravascular water content.
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PMID:Hyaluronan affects extravascular water in lungs of unanesthetized rabbits. 274 21

While Actinobacillus actinomycetemcomitans has been associated with rapidly progressive periodontal destruction in man, the closely related Haemophilus aphrophilus has not been related to periodontal disease. This may be due to differences in composition and structure of the lipopolysaccharides (LPS) of these dental-plaque bacteria, since LPS probably exerts a series of detrimental effects on the periodontium. LPS was prepared by the phenol-water procedure from the type strains of A. actinomycetemcomitans and H. aphrophilus, purified by hexane extraction and ultracentrifugation, and analyzed with gas chromatography and gas chromatography-mass spectrometry. While the lipid content of LPS from A. actinomycetemcomitans constituted 35.4%, it was only 18.4% in H. aphrophilus: 3-hydroxytetradecanoic and tetradecanoic acids were 21.1 and 14.3% in A. actinomycetemcomitans and 10.9 and 7.5% in H. aphrophilus. There were qualitative and quantitative differences in the polysaccharide portions of their LPS. A actinomycetemcomitans contained both D-glycero-D-mannoheptose and L-glycero-D-mannoheptose (7.8 and 11.3%); H. aphrophilus contained only L-glycero-D-mannoheptose (17.4%). The rhamnose, fucose, galactose, glucose, and glucosamine/galactosamine contents in A. actinomycetemcomitans were 2.6, 5.2, 10.1, 22.4, and 5.2%, respectively; in H. aphrophilus, they were 2.1, 2.6, 19.4, 36.4, and 3.7%. Chemical differences in LPS from A. actinomycetemcomitans and H. aphrophilus may contribute to the divergence in periodontopathogenic potential of these organisms and help taxonomic differentiation.
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PMID:Chemical differences in lipopolysaccharides from Actinobacillus (Haemophilus) actinomycetemcomitans and Haemophilus aphrophilus: clues to differences in periodontopathogenic potential and taxonomic distinction. 277 74

The effect of increasing concentrations of lipid X (2,3-bis(3-hydroxymyristoyl)-alpha-D-glucosamine 1-phosphate) on the phase behaviour of EPC (egg phosphatidylcholine) and EPE (egg phosphatidylethanolamine) is studied at a pH greater than or equal to 7 where lipid X carries one to two negative charges. Small amounts of lipid X (molar ratio approximately 0.01) induce continuous swelling of EPC and EPE bilayers and consequently the formation of large unilamellar vesicles in excess water. In many respects, the effect of lipid X on EPC and EPE bilayers is similar to that of phosphatidic acid. However, lipid X/EPC mixtures form micelles in excess lipid X whereas mixtures of phosphatidic acid/EPC vesiculate at all ratios. The same is true for lipid X/EPE mixtures. Small unilamellar vesicles of an average diameter of 40 nm form spontaneously upon dispersion of a dry lipid X/EPE film (molar ratio = 10). Unsonicated dispersions of lipid X/EPC (molar ratio = 1) are subjected to pH-jump treatment which involves raising of the pH to 11-12 and subsequent lowering of the pH to between 7.5 and 8.5. Such a treatment has little effect on the vesicle size and size distribution as compared to a control dispersion at pH 8.2. The mean size is determined to be 92 +/- 60 nm. Electron micrographs of freeze-fractured samples of lipid X/EPC (molar ratio = 1) reveal the presence of mainly micelles at pH 12. Upon lowering the pH to neutrality these micelles become unstable and aggregate/fuse rapidly to unilamellar vesicles (average diameter 95 +/- 40 nm). Sonication of equimolar mixtures of lipid X and EPC at pH 7 yields small unilamellar vesicles of a diameter of 20-25 nm as well as mixed micelles of a size between 15 and 17 nm. This behaviour is again different from that of mixed EPC/phosphatidic acid dispersions which form small unilamellar vesicles. The presence of lipid X in such mixtures does not prevent the aggregation/fusion to larger vesicles during freezing of the dispersion. As with pure EPC bilayers, stabilization is, however, achieved in the presence of 10% sucrose. This indicates that the covalently bonded glucosamine group of lipid X cannot substitute water of hydration in neighbouring EPC molecules.
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PMID:Phase behaviour of mixtures of lipid X with phosphatidylcholine and phosphatidylethanolamine. 292 79

Chemical reduction of human plasma lipoprotein(a) (Lp(a)) yielded two water-soluble products which were separated by rate zonal ultracentrifugation. Apolipoprotein(a) (apo(a)) was completely recovered from the bottom of the gradient, whereas lipoprotein(a-) (Lp(a-)), which contained all of the lipids and apo-B100 of Lp(a), floated. By the techniques of circular dichroism and viscometry Lp(a-) was identical to low density lipoprotein (LDL). Lp(a-) was slightly larger in mass than autologous LDL and contained proportionally more triglyceride. The difference in mass between Lp(a) and Lp(a-) was accounted for by the loss of 2 molecules of apo(a) from the Lp(a) particle. The molecular weight of reduced and carboxymethylated apo(a) was 281,000 as determined by sedimentation equilibrium in 6 M guanidine HCl. By circular dichroism the structure of apo(a) was mostly random (71%) with the remainder representing 8% alpha-helix and 21% beta-sheet; its intrinsic viscosity, 28.3 cm3/g, was consistent with an extended flexible coil. The amino acid composition was characterized by an unusually high content of proline (11.4 mol %) as well as tryptophan, tyrosine, arginine, threonine, and a low amount of lysine, phenylalanine, and isoleucine. Apo(a) contained 28.1% carbohydrate by weight represented by mannose, galactose, galactosamine, glucosamine, and sialic acid in an approximate molar ratio of 3:7:5:4:7, respectively. Overall, the structure of Lp(a) appears to be consistent with a rigid spherical LDL-like core particle which, as a consequence of its association with a flexible glycoprotein such as apo(a), favors the entrapment of significant amounts of hydrodynamically associated solvent. Furthermore, the Lp(a-) remnant generated by the removal of apo(a) from Lp(a) was similar in structure but not identical to autologous LDL.
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PMID:Physicochemical properties of apolipoprotein(a) and lipoprotein(a-) derived from the dissociation of human plasma lipoprotein (a). 294 20

A series of analogues of uridine 5'-diphosphate glucose and uridine 5'-diphosphate glucosamine have been synthesized by reaction of 2,3,4,6-tetra-O-benzyl-, 2,3,4,6-tetra-O-benzoyl-, 2,3,4,6-tetra-O-acetyl-, and 2,3,4,6-tetra-O-palmitoyl-alpha-D-glucopyranose and 2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-alpha-D-glucopyranose with chlorosulfonyl isocyanate and 2',3'-O-isopropylideneuridine. Isopropylidene and acetyl groups of the resulting 5'-O-[[[[(alpha-D-glucopyranosyl)oxy]carbonyl]amino]sulfonyl] -2',3'-O-isopropylideneuridine derivatives were removed by reaction with a TFA/water (5:1) mixture and methanolic ammonia, respectively. The 5'-O-[[[[(2",3",4",6"-tetra-O-benzyl-and 2",3",4",6"-tetra-O-benzoyl-alpha-D-glucopyranosyl)oxy]carbonyl] amino]sulfonyl]-2',3'-O-isopropylideneuridine (13 and 19) and the corresponding deisopropylidenated derivatives showed antiviral activity as determined by the inhibition of the cytopathic effect induced by HSV-1 replication and by the plaque assay method. Compound 13 inhibited glycosylation of proteins in HSV-1 infected HeLa cells.
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PMID:Uridine 5'-diphosphate glucose analogues. Inhibitors of protein glycosylation that show antiviral activity. 298 23

Insulin action may involve the intracellular generation of low molecular weight substances that modulate certain key enzymes. The production of two substances that regulate the activity of adenosine 3',5'-monophosphate phosphodiesterase was evaluated in cultured myocytes by incorporation of radiolabeled precursors. Insulin caused the rapid hydrolysis of a chemically undefined membrane glycolipid, resulting in the production of two related complex carbohydrates as well as diacylglycerol. Both the glycolipid precursor and the aqueous products were monitored by labeling with radioactive inositol and glucosamine. Depletion of the labeled precursor and the appearance of labeled water-soluble products and diacylglycerol occurred within 30 seconds after hormone treatment and was followed by rapid resynthesis of the precursor. The aqueous products that were radioactively labeled appeared chromatographically and electrophoretically identical to phosphodiesterase modulating activities produced by insulin from the same cells. The purified radiolabeled and bioactive substances had similar chemical properties. Hydrolysis of the glycolipid precursor and subsequent generation of products could be reproduced by incubation of extracted lipids with a phosphatidylinositol-specific phospholipase C. These studies suggest that insulin stimulates an endogenous, selective phospholipase C activity that hydrolyzes a novel glycolipid, resulting in the generation of a complex carbohydrate-phosphate substance containing inositol and glucosamine that may mediate some of the actions of the hormone.
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PMID:Insulin-stimulated hydrolysis of a novel glycolipid generates modulators of cAMP phosphodiesterase. 301 98

Lipopolysaccharide (LPS) extracted from the deep rough mutant of Escherichia coli D31m4 was disaggregated with 0.1 M EDTA, pH 7.0, and fractionated on a diethylaminoethyl-cellulose column to yield the biphosphate form of LPS. After methylation, the derivative was purified by reverse-phase high performance liquid chromatography using a C18-bonded silica cartridge. A linear gradient of 50-100% isopropyl alcohol/water (93:7, v/v) in acetonitrile/water (93:7, v/v) was used over a period of 60 min. The derivatized LPS showed a single major peak by high performance liquid chromatography, and this hexamethyl hexaacyl LPS was recovered and subjected to chemical analysis, plasma desorption mass spectrometry, and nuclear magnetic resonance (NMR) spectroscopy. Chemical analysis of the purified hexamethyl LPS quantitated certain key chemical compositions. Plasma desorption mass spectrometry showed a molecular ion (M + CH2 + Na)+ at m/z 2360, which established the molecular formula and Mr to be C116H214N2O39P2 and 2323, respectively. Thus, it contained two each of glucosamine, 2-keto-3-deoxyoctonate, and phosphate; four beta-hydroxymyristates; one laurate; and one myristate. NMR spectroscopy confirmed the locations of the four ester-linked fatty acyl groups. Based on these results and the known structure of free lipid A, the complete structure of the deep-rough chemotype LPS from E. coli can now be presented with confidence. This is the first report of a successful purification to homogeneity and the characterization of the simplest of the LPS at the intact level. This study shows that the natural distribution of the lipid A moiety of LPS from E. coli D31m4 is hexaacyl/pentaacyl in a molar ratio of greater than 90:less than 10. Acid hydrolysis of LPS causes the formation of the lower homologues of the free lipid A.
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PMID:Complete structural determination of lipopolysaccharide obtained from deep rough mutant of Escherichia coli. Purification by high performance liquid chromatography and direct analysis by plasma desorption mass spectrometry. 313 69


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