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PubMed1980

Incorporation of glucosamine by activated human neutrophils. A myeloperoxidase-mediated process.

Zymosan-activated neutrophils were found to incorporate large amounts of [3H]glucosamine into TCA-precipitable material as compared with resting cells. The burst of glucosamine incorporation began 2 min after zymosan exposure and lasted 3 to 5 min, after which the incorporation rate returned to that of resting cells. Studies with cells from patients with chronic granulomatous disease and hereditary myeloperoxidase deficiency as well as experiments with inhibitors indicated that glucosamine incorporation required both the respiratory burst and the myeloperoxidase system. SDS-polyacrylamide gel electrophoresis of [3H]glucosamine-containing TCA precipitates from zymosan-activated cells revealed radioactivity migrating throughout the length of the gel. The radioactivity in precipitates from resting cells or cells activated in the presence of a small amount of a myeloperoxidase inhibitor was found in a peak migrating close to the tracking dye. These results indicate that zymosan-activated neutrophils are able to incorporate glucosamine into protein by a process dependent on H2O2 and myeloperoxidase. The biosynthetic significance of this phenomenon is not certain, but it most likely represents the reaction of amino sugar with macromolecular degradation products formed by the action of the myeloperoxidase system on cellular and particulate constituents.

Glucosamine↗

PubMed1994

Efficacy and safety of intramuscular glucosamine sulfate in osteoarthritis of the knee. A randomised, placebo-controlled, double-blind study.

Glucosamine sulfate (Dona, CAS 29031-19-4) is a drug used in the treatment of osteoarthritis. When orally given, it is more effective than placebo and at least as effective as non-steroidal anti-inflammatory drugs in relieving osteoarthritis symptoms. The aim of this multicentre, randomised, placebo-controlled, double-blind, parallel-group study was to assess the efficacy and safety of glucosamine sulfate intramuscularly given on the same parameters. 155 out-patients with knee osteoarthritis (Lequesne's criteria), radiological stage between I and III, Lequesne's severity index of at least 4 points and symptoms for at least 6 months, were treated with i.m. glucosamine sulfate (or placebo) 400 mg twice a week for 6 weeks. Clinic visits were performed at enrollment, after a 2-week baseline, at weekly intervals during treatment and 2 weeks after drug discontinuation. Responders to treatment were considered those patients with a reduction of at least 3 points in the Lequesne index, together with a positive overall judgement by the investigator. The Lequesne index was slightly over 10 points in average in both groups at the beginning of treatment. A significant decrease in the index was observed for glucosamine compared to placebo (3.3 vs. 2.0 points in average, respectively; p < 0.05, Student's t-test). The responder rate in the evaluable patients was 55% with glucosamine (n = 73) and only 33% (n = 69) with placebo (p = 0.012, Fisher's Exact Test). According to the intention-to-treat approach, considering also drop-outs, these proportions were 51% vs. 30% (p = 0.015).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

Structure of lipid A component of Rhizobium leguminosarum bv. phaseoli lipopolysaccharide. Unique nonphosphorylated lipid A containing 2-amino-2-deoxygluconate, galacturonate, and glucosamine.

The structure of lipid A from the lipopolysaccharide of Rhizobium leguminosarum bv. phaseoli (wild type strain CE3) was investigated by alkylation analysis, nuclear magnetic resonance spectroscopy, and electrospray and fast atom bombardment mass spectrometry of the de-O-acylated lipid A. The lipid A carbohydrate backbone was shown to be a trisaccharide containing galacturonic acid, glucosamine, and the unique sugar 2-amino-2-deoxygluconic acid, previously unreported in lipopolysaccharides. Nuclear magnetic resonance spectroscopy and ethylation analyses revealed that the galacturonic acid is alpha-1,4-linked to the glucosamine, while the amino aldonic acid residue, which may exist as the 1,5-lactone, is attached as an aglycone to the glucosamine and, thus, occupies the reducing end of the molecule. The resulting backbone is hydrophilic and analogous to the commonly observed bisphosphorylated glucosamine disaccharide from enteric bacterial lipopolysaccharides in that both the nonreducing and reducing ends carry negatively charged substituents. The fatty acids of the R. leguminosarum lipid A are attached both as O- and N-acyl substituents to glucosamine and 2-aminogluconate. All fatty acids are hydroxylated consisting of 3-hydroxymyristate (3-OH-C14.0), 3-hydroxypentadecanoate (3-OH-C15.0), 3-hydroxypalmitate (3-OH-C16.0), 3-hydroxystearate (3-OH-C18.0), and 27-hydroxyoctacosanoate (27-OH-C28.0) in the approximate mole ratio 3:0.2:1:0.6:1. Unlike lipid As from enteric bacteria, the R. leguminosarum lipid A lacks 3-acyloxyacyl substituents; however, the long chain 27-hydroxy fatty acid carries ester-linked beta-hydroxybutyrate at the 27-hydroxy position. Fast atom bombardment mass spectrometry of the de-O-acylated lipid A demonstrated the presence of 2 molecular species that differ by 28 mass units due to fatty acid heterogeneity at the two amide linkages. One species carries amide-linked 3-OH-C14.0 and 3-OH-C16.0; the second species carries 3-OH-C14.0 and 3-OH-C18.0. Each molecular species also exists as the aldonolactone, yielding molecular ions at ((M+H)+)-18. The heterogeneity in the amide-linked fatty acids further distinguishes the Rhizobium lipid A from enteric lipid As.

Carbohydrate Conformation↗

PubMed1998

The role of glucosamine sulfate and chondroitin sulfates in the treatment of degenerative joint disease.

Successful treatment of osteoarthritis must effectively control pain, and should slow down or reverse progression of the disease. Biochemical and pharmacological data combined with animal and human studies demonstrate glucosamine sulfate is capable of satisfying these criteria. Glucosamine sulfate's primary biological role in halting or reversing joint degeneration appears to be directly due to its ability to act as an essential substrate for, and to stimulate the biosynthesis of, the glycosaminoglycans and the hyaluronic acid backbone needed for the formation of proteoglycans found in the structural matrix of joints. Chondroitin sulfates, whether they are absorbed intact or broken into their constituent components, similarly provide additional substrates for the formation of a healthy joint matrix. Evidence also supports the oral administration of chondroitin sulfates for joint disease, both as an agent to slowly reduce symptoms and to reduce the need for non-steroidal anti-inflammatory drugs. The combined use of glucosamine sulfate and chondroitin sulfates in the treatment of degenerative joint disease has become an extremely popular supplementation protocol in arthritic conditions of the joints. Although glucosamine sulfate and chondroitin sulfates are often administered together, there is no information available to demonstrate the combination produces better results than glucosamine sulfate alone.

Chondroitin Sulfates↗

PubMed1994

Mucosal glucosamine synthetase activity in inflammatory bowel disease.

Abnormalities in colonic glycoprotein synthesis have been implicated in the pathogenesis of ulcerative colitis and Crohn's disease. Glucosamine synthetase is the rate-limiting step in the biosynthesis of gastrointestinal glycoprotein and has been measured in control subjects (N = 23) and patients with ulcerative colitis (N = 26) or Crohn's disease of the colon (N = 20) classified according to the macroscopic status of the rectum. Glucosamine synthetase activity was relatively constant around the normal colon but lower levels were found in the terminal ileum. In ulcerative colitis, glucosamine synthetase activity was similar to controls (24.0 +/- 1.9) mmol/g wet (wt/hr) irrespective of disease activity (quiescent: N = 13, = 27.3 +/- 1.9; active N = 16, = 26.2 +/- 2.3). Rectal glucosamine synthetase activity was normal in the presence of active Crohn's proctocolitis (29.4 +/- 3.1) but raised in patients with Crohn's colitis and rectal sparing (37.2 +/- 4.9 P < 0.02). Glucosamine synthetase activity was strongly influence by the degree of epithelial preservation.

Colitis, Ulcerative↗

PubMed1978

Synthesis of UDP-N-[1-14C]acetyl D-glucosamine and UDP-N-[1-14C]acetyl-D-galactosamine from [1-14C]acetate.

Procedures for the preparation of UDP-N-[1-14C]acetyl-D-glucosamine and UDP-N-[1-14C]acetyl-D-galactosamine with very high specific activities are described. The overall yield based on the amount of [1-14C]acetate used is greater than 80%. The N-acetyl-D-glucosamine-alpha-1-phosphate used in this synthesis is prepared by phosphorylation of tetraacetyl-D-N-acetylglucosamine with crystalline phosphoric acid. N-acetyl-D-glucosamine-alpha-1-phosphate is then deacetylated in anhydrous hydrazine with hydrazine sulfate as a catalyst. D-glucosamine-alpha-1-phosphate is N-acetylated with [14C]acetate using N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline as the coupling agent. The acetylated product is coverted to the UDP derivative with yeast UDP-N-acetyl-D-glucosamine pyrophosphorylase. UDP-N-[1-14C]acetylgalactosamine is prepared by acetylation of UDP-galactosamine using [1-14C]acetate and N-ethoxy-carbonyl-2-ethoxy-1,2-dihydroquinoline. UDP-galactosamine is prepared enzymatically using galactokinase and galactose-1-phosphate uridyltransferase. The labeled products, isolated and characterized by ion-exchange and paper chromatography, were active as substrates in glycosyl transferase systems.

Acetic Acid↗

PubMed1992

Purification and characterization of glucosamine-6-phosphate deaminase from dog kidney cortex.

Glucosamine-6-phosphate deaminase (EC 5.3.1.10) from dog kidney cortex was purified to homogeneity, as judged by several criteria of purity. The purification procedure was based on two biospecific affinity chromatography steps, one of them using N-epsilon-amino-n-hexanoyl-D-glucosamine-6-phosphate agarose, an immobilized analog of the allosteric ligand, and the other by binding the enzyme to phosphocellulose followed by substrate elution, which behaved as an active-site affinity chromatography. The enzyme is an hexameric protein of about 180 kDa composed of subunits of 30.4 kDa; its isoelectric point was 5.7. The sedimentation coefficient was 8.3S, and its frictional ratio was 1.28, indicating that dog deaminase is a globular protein. The enzyme displays positive homotropic cooperativity toward D-glucosamine-6-phosphate (Hill coefficient = 2.1, pH 8.8). Cooperativity was completely abolished by saturating concentrations of GlcNAc6P; this allosteric modulator activated the reaction with a typical K-effect. Under hyperbolic kinetics, a Km value of 0.25 +/- 0.02 mM for D-glucosamine-6-phosphate was obtained. Assuming six catalytic sites per molecule, kcat is 42 s-1. Substrate-velocity data were fitted to the Monod's allosteric model for the exclusive-binding case for both substrate and activator, with two interacting substrate sites. The Kdis for N-acetyl-D-glucosamine-6-phosphate was estimated at 14 microM.

Aldose-Ketose Isomerases↗

PubMed2002

Effect of N-acetyl-D-glucosamine, and glycerol concentration and equilibration time on acrosome morphology and motility of frozen-thawed boar sperm.

A series of experiments were conducted to determine the effect of N-acetyl-D-glucosamine, glycerol concentration and equilibration time for the freezing of boar spermatozoa in 5 ml maxi-straws. The optimum final glycerol concentration in the diluent with 0.05% N-acetyl-D-glucosamine in the first diluent was 2-3% and the optimum glycerol equilibration time was 2-3h. In conclusion, we recommend the first diluent containing 11% lactose hydrate, 20% egg yolk and 0.05% N-acetyl-D-glucosamine in 100ml distilled water, and the second diluent containing 11% lactose hydrate, 20% egg yolk, 4% glycerol and 1% orvus es paste for the diluents of boar sperm freezing. Also, we found out that 0.05% soluble N-acetyl-D-glucosamine was the optimum concentration in the first diluent and a concentration of 0.05% soluble N-acetyl-D-glucosamine significantly enhanced the cryopreservation of boar spermatozoa.

Acetylglucosamine↗

PubMed1988

Glucosamine synthetase from Escherichia coli: kinetic mechanism and inhibition by N3-fumaroyl-L-2,3-diaminopropionic derivatives.

N3-(4-Methoxyfumaroyl)-L-2,3-diaminopropionic acid (FMDP; 1, R = OMe), a member of a new class of glutamine analogues, has been investigated as an inhibitor of pure Escherichia coli glucosamine synthetase. Product and dead-end inhibition studies indicate an ordered association to the enzyme with the sugar molecule binding prior to substrate or inhibitor. The inactivation exhibits pseudo-first-order kinetics, is irreversible, and occurs faster in the presence of fructose 6-phosphate, a behavior previously reported [Chmara, H., Andruszkiewicz, R., & Borowski, E. (1986) Biochim. Biophys. Acta 870,357] for the partially purified enzyme from Salmonella typhimurium. The ratio kinact/Kirr of 5500 makes compound 1 (R = OMe) one of the most efficient inhibitors of glucosamine synthetase to date. Inhibition occurs with partial covalent incorporation of L-FMDP into glucosamine synthetase. In the presence of fructose 6-phosphate, enzyme inactivation with [2-3H]-DL-FMDP is associated with the incorporation of 0.75 equiv of inhibitor and with the modification of 0.78 thiol residue per enzyme subunit. This result is the first evidence for covalent entrapment of the entire inhibitor molecule following FMDP-mediated glucosamine synthetase inactivation. Preliminary inactivation with 6-diazo-5-oxo-L-norleucine, known to alkylate selectively the NH2-terminal cysteine residue, completely prevents radioactivity incorporation. Therefore, this inhibitor is postulated to covalently modify glucosamine synthetase through direct addition of the thiol nucleophile from the terminal cysteine residue to the Michael acceptor 1, so acting as an affinity label rather than a mechanism-based inhibitor.

Alanine↗

PubMed1980

Kinetic characterization of N-acetyl-D-glucosamine kinase from rat liver and kidney.

1. Under normal assay conditions the N-acetyl-D-glucosamine kinases from rat liver and kidney show a pH-dependent lag phase before reaching a steady state, which is probably due to reversible dissociation of the dimeric enzyme. 2. The enzyme catalyses the phosphorylation of N-acetyl-D-glucosamine, N-acetyl-D-mannosamine and D-glucose at pH 7.5, with apparent Km values of 0.06, 0.95 and 600 mM respectively for the enzyme from liver and 0.04, 1.0 and 410 mM respectively for the kidney enzyme. It is strongly inhibited by ADP. 3. The interaction between the enzymes and acceptor substrates shows non-Michaelian kinetics with respect to N-acetyl-D-glucosamine but normal behaviour towards N-acetyl-D-mannosamine and D-glucose. 4. Both N-acetyl-D-glucosamine and N-acetyl-D-mannosamine inhibit the phosphorylation of D-glucose; this inhibition appears to be mixed in character. 5. The facts that the enzymes catalyse the phosphorylation of N-acetyl-D-mannosamine and D-glucose do not detract from the designation of the enzymes as N-acetyl-D-glucosamine kinase. Phosphorylation of glucose in vivo by these kinases is unlikely.

Acetylglucosamine↗

PubMed1992

A cDNA clone for human glucosamine-6-sulphatase reveals differences between arylsulphatases and non-arylsulphatases.

Glucosamine-6-sulphatase is an exo-hydrolase required for the lysosomal degradation of heparan sulphate and keratan sulphate. Deficiency of glucosamine-6-sulphatase activity leads to the lysosomal storage of the glycosaminoglycan, heparan sulphate and the monosaccharide sulphate N-acetylglucosamine 6-sulphate and the autosomal recessive genetic disorder mucopolysaccharidosis type IIID. Glucosamine-6-sulphatase can be classified as a non-arylsulphatase since, relative to arylsulphatase B, it shows negligible activity toward 4-methylumbelliferyl sulphate. We have isolated human cDNA clones and derived amino acid sequence coding for the entire glucosamine-6-sulphatase protein. The predicted sequence has 552 amino acids with a leader peptide of 36 amino acids and contains 13 potential N-glycosylation sites, of which it is likely that 10 are used. Glucosamine-6-sulphatase shows strong sequence similarity to other sulphatases such as the family of arylsulphatases, although the degree of similarity is not as high as that between members of the arylsulphatase family. This pattern of inter- and intra-family similarity delineates regions and amino acid residues that may be critical for sulphatase function and substrate specificity.

Amino Acid Sequence↗

PubMed2005

Structure and kinetics of a monomeric glucosamine 6-phosphate deaminase: missing link of the NagB superfamily?

Glucosamine 6-phosphate is converted to fructose 6-phosphate and ammonia by the action of the enzyme glucosamine 6-phosphate deaminase, NagB. This reaction is the final step in the specific GlcNAc utilization pathway and thus decides the metabolic fate of GlcNAc. Sequence analyses suggest that the NagB "superfamily" consists of three main clusters: multimeric and allosterically regulated glucosamine-6-phosphate deaminases (exemplified by Escherichia coli NagB), phosphogluconolactonases, and monomeric hexosamine-6-phosphate deaminases. Here we present the three-dimensional structure and kinetics of the first member of this latter group, the glucosamine-6-phosphate deaminase, NagB, from Bacillus subtilis. The structures were determined in ligand-complexed forms at resolutions around 1.4 Angstroms. BsuNagB is monomeric in solution and as a consequence is active (k(cat) 28 s(-1), K(m(app)) 0.13 mM) without the need for allosteric activators. A decrease in activity at high substrate concentrations may reflect substrate inhibition (with K(i) of approximately 4 mM). The structure completes the NagB superfamily structural landscape and thus allows further interrogation of genomic data in terms of the regulation of NagB and the metabolic fate(s) of glucosamine 6-phosphate.

Aldose-Ketose Isomerases↗

PubMed1997

Inhibition of rabbit gastric glucosamine synthetase activity by Cu2+, Zn2+ and Se4+.

The effects of Fe2+, Cu2+, Zn2+ and Se4+ on the activity of glucosamine synthetase, the rate-limiting enzyme of mucus synthesis, in rabbit gastric corporal mucosa were examined. Cu2+, Zn2+ and Se4+ inhibited the glucosamine synthetase activity at concentrations ranging from 1 to 10 microM (Cu2+, 8-98% inhibition; Zn2+, 10-99% inhibition; Se4+, 32-89% inhibition). The inhibitory effects of these three ions were much stronger than that of UDP-N-acetylglúcosamine known as a representative inhibitor of the glucosamine synthetase activity (10 microM, 52% inhibition). Fe2+ had no significant effect on the glucosamine synthetase activity up to 100 microM. These results suggest that Cu2+, Zn2+ and Se4+ can be potent inhibitors of gastric glucosamine synthetase activity.

Animals↗

PubMed1997

Effect of 13-hydroperoxyoctadecadienoic acid on the glucosamine synthetase activity in rabbit gastric mucosa.

The effect of 13-hydroperoxyoctadecadienoic acid (13-HPODE) on the activity of glucosamine synthetase, the rate-limiting enzyme of mucus synthesis, in rabbit gastric corporal mucosa was examined. 13-HPODE inhibited the glucosamine synthetase activity at concentrations ranging from 10 to 100 microM. The effect was concentration-dependent, and the concentration required for 50% inhibition was approximately 20 microM. Experiments utilizing Fe2+ and 13-hydroxyoctadecadienoic acid revealed that the inhibitory effect of 13-HPODE on the glucosamine synthetase activity is not due to the alcohol adduct and hydroxyl radical which are expected to be formed from 13-HPODE, and that the hydroperoxyl functional group is a prerequisite. The fact that tert-butyl hydroperoxide exhibited about 50 times weaker inhibition than 13-HPODE indicates the relative specificity of fatty acyl hydroperoxides in the modulation of the glucosamine synthetase activity. These results suggest that 13-HPODE has the potential to modulate the synthesis of gastric mucus by affecting the glucosamine synthetase activity.

Animals↗

PubMed1965

A STUDY ON THE GLUCOSAMINE-CONTAINING CONSTITUENTS OF THE SEEDS OF KIDNEY BEANS (PHASEOLUS VULGARIS).

1. The constituents of the seeds of kidney beans containing glucosamine that could be released by acid hydrolysis (0.5 n-hydrochloric acid at 100 degrees ) were extracted into the phenol-rich phase on partitioning between phenol and water at 70 degrees . 2. These materials were also brought into solution on extracting the seeds with water (incomplete), or preferably with a slightly alkaline buffer in the absence of phenol. When these solutions were heated at 100 degrees or treated with trichloroacetic acid, all the materials containing acid labile glucosamine were carried down with the precipitate. Treatment with pepsin rendered the materials containing glucosamine soluble again. 3. All proteins in these extracts of kidney bean were found to be associated with various amounts of neutral and amino sugars by high-voltage electrophoresis and chromatography on Sephadex G-200 columns. 4. The isolation and crystallization of the main sugar components, d-glucosamine and d-mannose, are described and their significance in plant glycoproteins is discussed.

Biochemical Phenomena↗

PubMed1983

Cultured fibroblasts in Huntington's disease. II. Effects of glucosamine.

It has been proposed that there is a generalized membrane defect in Huntington's disease (HD) that is expressed in non-neuronal tissue. This membrane abnormality has been linked to a glucosamine dependence of HD cells that can be demonstrated in cultured skin fibroblasts. Twenty HD, "at-risk," and normal cell lines were used in studies of growth, viability, and adhesion in Eagle's Minimum Essential Medium with dialyzed serum or serum separated by a fractionating column (Sephadex G50). The effects of the supplementation of these media with serine, glutamine, glucosamine, and N-acetylglucosamine (0.1mM) on cell growth were determined. The growth of cells in the presence of glucosamine (0mM to 2mM) and N-acetylglucosamine (1mM) was monitored. The HD cells grew slightly better than normal or at-risk cells in the depleted media and attached to the culture surface better. However, the glucosamine dependence of HD cells was not demonstrated.

Acetylglucosamine↗

PubMed1982

Analysis of glycosaminoglycans of flow sorted cells: incorporation of [35S]sulfate and [3H]glucosamine into glycosaminoglycans of B16-F10 cells during the cell cycle.

The incorporation of [35S]sulfate and [3H] glucosamine into cetyl pyridinium chloride (CPC) precipitable glycosaminoglycans was determined in B16-F10 cultured cells sorted with respect to DNA content. Incorporation into surface material was measured indirectly as the difference between the radioactivity of control and trypsin treated cells. Approximately 80% of the total cellular [35S] sulfate labeled CPC precipitable material, but only 5% of that labeled by [3H]glucosamine, was removed by this mild trypsin treatment. Incorporation of [35S]sulfate into the trypsin removable surface material increased progressively from G1 to S to F2 + M in both long-term (48 hours) and short-term (1 hour) labeled cells, while the ratio of surface to total incorporated [35S]sulfate remained relatively constant. Incorporation of [35S]sulfate into total cellular glycosaminoglycans in long- and short-term labeled cells increased as cells progressed from G1 to S to G2 + M; the incorporation of [3H]glucosamine into CPC precipitable material also increased progressively from G1 to S to G2 + M in long-term labeled cells but was greater during S phase relative to G1 or G2 + M in short-term labeled cells. The degree of sulfation of glycosaminoglycans as represented by the ratio of [35S]sulfate to [3H]glucosamine of double labeled cells was relatively constant in long-term labeled cells but was increased during the G1 and G2 + M phases of short-term labeled cells. Comparison of the degree of sulfation of short-term with long-term labeled cells suggests that highly sulfated glycosaminoglycans may be turned over more rapidly during G1 and G2 + M phases of the cell cycle.

Animals↗

PubMed1982

Lymphokine-induced uptake of [14C]glucosamine, [14C]glucose, and [3H]leucine by macrophages.

Lymphokine-activated (LK+) and control (LK-) macrophages were cultured for 66 h and then pulsed with [14C]glucosamine. Uptake of [14C]glucosamine was greater in LK+ than in LK- cultures. If, after 66 h, the medium was replaced with fresh medium and then pulsed with either [14C]glucose or [14C]glucosamine, the uptake of isotope was greatly reduced compared to cultures with no change of medium. However, uptake of both radiolabeled substances was still found to be greater in LK+ cultures than in LK- cultures. Although uptake of both substances was enhanced by lymphokines, the uptake kinetics of each isotope was different. Under similar conditions the uptake of [3H]leucine was not enhanced by lymphokine activation. These data are interpreted to mean that LK+ macrophages are metabolically stimulated and utilize more glucose and glucosamine. The difference in kinetics implies a different utilization by macrophages for each substance.

Animals↗