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PubMed1997

Characterization and cytokine-stimulating activities of acidic heteroglycans from Tremella fuciformis.

Four acidic heteroglycans, T2a-T2d, were isolated from the body of Tremella fuciformis Berk. They contained 1.9%-2.9% of acetyl groups and were composed of mannose (Man), glucuronic acid (GlcA), and small amounts of xylose (Xyl), glucose (Glc), and fucose (Fuc). According to methylation analysis they had a mannan backbone consisting of 3-linked Man, and side chains containing glucosyl, mannosyl, fucosyl, xylosyl, and glucuronic acid residues. The side chains were attached through O-2, O-4, or O-6 in about 40 percent of backbone mannosyl residues. Molecular masses of the four polysaccharides were 410, 250, 34, and 20 kDa, respectively. T2a-T2d induced human monocytes to produce interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor (TNF) in vitro. The products of Smith degradation (T2a-S) and lithium degradation (T2a-L) of T2a and the product of deacetylation (T2b-D) of T2b also induced monocytes to secret IL-1 as efficiently as the original polysaccharides, indicating that xylosyl and glucuronic acid residues as well as acetyl groups were not important to promote the cytokine-stimulating activity.

Cells, Cultured↗
PubMed2001

Functional characterization of a novel xylanase from a corn strain of Erwinia chrysanthemi.

A beta-1,4-xylan hydrolase (xylanase A) produced by Erwinia chrysanthemi D1 isolated from corn was analyzed with respect to its secondary structure and enzymatic function. The pH and temperature optima for the enzyme were found to be pH 6.0 and 35 degrees C, with a secondary structure under those conditions that consists of approximately 10 to 15% alpha-helices. The enzyme was still active at temperatures higher than 40 degrees C and at pHs of up to 9.0. The loss of enzymatic activity at temperatures above 45 degrees C was accompanied by significant loss of secondary structure. The enzyme was most active on xylan substrates with low ratios of xylose to 4-O-methyl-D-glucuronic acid and appears to require two 4-O-methyl-D-glucuronic acid residues for substrate recognition and/or cleavage of a beta-1,4-xylosidic bond. The enzyme hydrolyzed sweetgum xylan, generating products with a 4-O-methyl-glucuronic acid-substituted xylose residue one position from the nonreducing terminus of the oligoxyloside product. No internal cleavages of the xylan backbone between substituted xylose residues were observed, giving the enzyme a unique mode of action in the hydrolysis compared to all other xylanases that have been described. Given the size of the oligoxyloside products generated by the enzyme during depolymerization of xylan substrates, the function of the enzyme may be to render substrate available for other depolymerizing enzymes instead of producing oligoxylosides for cellular metabolism and may serve to produce elicitors during the initiation of the infectious process.

Circular Dichroism↗
PubMed1994

The metabolism of 2-fluoro-2-deoxy-D-glucose in human chondrocytes and its incorporation into keratan sulfate proteoglycans.

The incorporation of 2-fluoro-2-deoxy-D-[14C]glucose in proteoglycans was investigated in a cell culture system, where human articular chondrocytes were cultured in high-cell-density thin-layer soft agarose. The proteoglycans were solubilized from the culture medium and the cell layer fraction by extracting with a guanidine hydrochloride buffer and purified by an ion-exchange-chromatography (DEAE-Sepharose CL-6B). With enzymic decomposition experiments concerning the glycosaminoglycan side-chains it could be shown that 65-69% were digestible by keratanase, whereas 21-29% of the 14C-labeled proteoglycans were digested with chondroitinase AC/ABC. The main constituent of the 2-fluoro-2-deoxy-D-[14C]glucose-metabolites present in the glycosaminoglycan side chains of the proteoglycans was 2-fluoro-2-deoxy-D-[14C]galactose. Therefore, 2-fluoro-2-deoxy-D-glucose was preferentially incorporated into keratan sulfate. We investigated the effect of non-radioactive 2-fluoro-2-deoxy-D-glucose on UDP-sugar and proteoglycan biosynthesis after incubation periods of 1-30 h. A high 2-fluoro-2-deoxy-D-glucose concentration in the culture medium did not influence the pool size of UDP-N-acetylhexosamines, but UDP-D-glucose, UDP-D-galactose, UDP-D-glucuronic acid, UDP-2-fluoro-2-deoxy-D-glucose, UDP-2-fluoro-2-deoxy-D-galactose and UDP-2-fluoro-2-deoxy-D-glucuronic acid accumulated in the chondrocytes time dependently. In a pulse/chase experiment the retarded synthesis of fluorinated UDP-sugars was proved. The half-lives (t1/2) for UDP-2-fluoro-2-deoxy-D-glucose and UDP-2-fluoro-2-deoxy-D-galactose were about 7.7 h and 13.3 h, respectively. UDP-2-fluoro-2-deoxy-D-glucuronic acid could be found with delay. The incubation with 2-fluoro-2-deoxy-D-glucose and [14C]glucosamine resulted in a decreased radioactive labelling of chondroitin sulfate and keratan sulfate.

Cartilage, Articular↗
PubMed1995

Determination of antigen binding specificities of Cryptococcus neoformans factor sera by enzyme-linked immunosorbent assay.

The competitive binding specificities of glucuronoxylomannan (GXM) and its derivatives to factor sera of Cryptococcus neoformans were studied by enzyme-linked immunosorbent assay. An effort was made to determine the epitope specificity of each factor serum. Despite the presence of antigenic factor 1 on all serotypes of C. neoformans, variations in inhibition ability were observed with different GXMs. The panspecific component of factor serum 1 (antibody 1) appeared to be due to the presence of more than one antibody component. The activity was dependent on the 6-O-acetyl substituent. GXMs of serotypes A and D inhibited factor serum 2 equally well, indicating a low titer for the antibody 7 component. Serotype B GXM was a poor inhibitor, and serotype C GXM did not inhibit factor serum 2. The activity of factor serum 2 was 6-O-acetyl dependent. GXMs from typical serotype A and serotype D isolates were excellent inhibitors of factor serum 3. GXMs from serotype B were poorly inhibitory and serotype C did not inhibit factor serum 3. The activity of factor serum 3 was 6-O-acetyl dependent. The activity of factor serum 4 was due predominantly to antibody component 6. The activity of factor 4 was directed mainly against serotype C, and it was independent of 6-O-acetyl substitution Factor serum 5 was specific for serotype B GXMs. The inhibitory effect was independent of 6-O-acetyl substitution, but the effect was diminished by reduction of the glucuronic acid. The GXMs with a typical serotype C structure inhibited antibody 6. O deacetylation of the GXMs did not affect their inhibitory activity. However, reduction of glucuronic acid reduced factor serum 6 binding. Factor serum 8 was specific to serotype D; native GXMs of serotype A were slightly inhibitory. O deacetylation of the serotype D GXMs abrogated the inhibitory effect. O deacetylation alone abrogates the activity of antibody components 1, 2, 3, and 8. Reduction of glucuronic acid reduces the inhibitory activity of the GXM to antibody components 4, 5, and 6. Partial GXM structures and methyl glycosides did not effectively inhibit the activity of any of the factor sera.

Animals↗
PubMed2005

Critical elements of oligosaccharide acceptor substrates for the Pasteurella multocida hyaluronan synthase.

Three-dimensional structures are not available for polysaccharide synthases and only minimal information on the molecular basis for catalysis is known. The Pasteurella multocida hyaluronan synthase (PmHAS) catalyzes the polymerization of the alternating beta1,3-N-acetylglucosamine-beta1,4-glucuronic acid sugar chain by the sequential addition of single monosaccharides to the non-reducing terminus. Therefore, PmHAS possesses both GlcNAc-transferase and glucuronic acid (GlcUA)-transferase activities. The recombinant Escherichia coli-derived PmHAS enzyme will elongate exogenously supplied hyaluronan chains in vitro with either a single monosaccharide or a long chain depending on the UDP-sugar availability. Competition studies using pairs of acceptors with distinct termini (where one oligosaccharide is a substrate that may be elongated, whereas the other cannot) were performed here; the lack of competition suggests that PmHAS contains at least two distinct acceptor sites. We hypothesize that the size of the acceptor binding pockets of the enzyme corresponds to the size of the smallest high efficiency substrates; thus we tested the relative activity of a series of authentic hyaluronan oligosaccharides and related structural analogs. The GlcUA-transferase site readily elongates (GlcNAc-GlcUA)(2), whereas the GlcNAc-transferase elongates GlcUA-Glc-NAc-GlcUA. The minimally sized oligosaccharides, elongated with high efficiency, both contain a trisaccharide with two glucuronic acid residues that enabled the identification of a synthetic, artificial acceptor for the synthase. PmHAS behaves as a fusion of two complete glycosyltransferases, each containing a donor site and an acceptor site, in one polypeptide. Overall, this information advances the knowledge of glycosaminoglycan biosynthesis as well as assists the creation of various therapeutic sugars for medical applications in the future.

Carbohydrate Conformation↗
PubMed2002

Biosynthesis of chondroitin/dermatan sulfate.

Chondroitin sulfate and dermatan sulfate are synthesized as galactosaminoglycan polymers containing N-acetylgalactosmine alternating with glucuronic acid. The sugar residues are sulfated to varying degrees and positions depending upon the tissue sources and varying conditions of formation. Epimerization of any of the glucuronic acid residues to iduronic acid at the polymer level constitutes the formation of dermatan sulfate. Chondroitin/dermatan glycosaminoglycans are covalently attached by a common tetrasaccharide sequence to the serine residues of core proteins while they are adherent to the inner surface of endoplasmic reticulum/Golgi vesicles. Addition of the first sugar residue, xylose, to core proteins begins in the endoplasmic reticulum, followed by the addition of two galactose residues by two distinct glycosyl transferases in the early cis/medial regions of the Golgi. The linkage tetrasaccharide is completed in the medial/trans Golgi by the addition of the first glucuronic acid residue, followed by transfer of N-acetylgalactosamine to initiate the formation of a galactosaminoglycan rather than a glucosaminoglycan. This specific N-acetylgalactosaminyl transferase is different from the chondroitin synthase involved in generation of the repeating disaccharide units to form the chondroitin polymer. Sulfation of the chondroitin polymer by specific sulfotransferases occurs as the polymer is being formed. All the enzymes in the pathway for synthesis have been cloned, with the exception of the glucuronyl to iduronyl epimerase involved in the formation of dermatan residues.

Animals↗
PubMed1983

A microassay for UDP-glucose dehydrogenase.

An assay for UDP-glucuronic acid [J. Singh, L. R. Schwarz, and F. J. Wiebel, Biochem. J. 189, 369-372 (1980)] has been utilized for determining UDP-glucose dehydrogenase activity. The assay for UDP-glucuronic acid, a product of UDP-glucose dehydrogenase, is based on the fluorometric determination of D-glucuronosyl benzo(a)pyrene. This compound is formed from UDP-glucuronic acid and 3-hydroxybenzo(a)pyrene in a reaction catalyzed by the glycuronosyl transferase of guinea pig microsomes. Unreacted 3-hydroxybenzo(a)pyrene is removed by extraction with chloroform-methanol, and the amount of gluconosylbenzo(a)pyrene formed is determined fluorometrically. Because this assay for UDP-glucose dehydrogenase is about 500 times more sensitive than spectrophotometric assays, it can be used to measure the amount of enzyme extractable from milligram quantities of connective tissue. Some kinetic properties of UDP-glucose dehydrogenase extracted from rabbit tissue have been determined. No evidence of different forms of the enzyme in rabbit liver, cartilage, or corneal stroma was found.

Animals↗
PubMed1978

Human urinary metabolites of 3-(2',4',5'-triethoxybenzoyl)propionic acid, a new biliary smooth muscle relaxant with choleretic activity.

Biotransformation of 3-(2',4',5'-triethoxybenzoyl)propionic acid (tri-, ethoxybenzoylpropionate) was studied in man using isotopic cluster technique. From the 24 h urine of a male volunteer given an equimolar mixture of non-labelled and pentadeuterium-labelled triethoxybenzoylpropionate (1 mg/kg) orally, the parent drug, 3-(2',5'-diethoxy-4'-hydroxybenzoyl)propionic acid (4'-phenol) and 3-(2',4'-diethoxy-5'-hydroxybenzoyl)propionic acid (5'-phenol) were isolated and identified by g.l.c.-mass spectrometry. 2. Urinary components were also quantified by mass chromatography: the parent drug (67.4% of dose) and 4'- and 5'-phenols in a mixture (20.3%). More than 80% of urinary triethoxybenzoylpropionate was present as its glucuronic acid ester, as evidenced by using beta-glucuronidase and saccharo-1,4-lactone, a specific inhibitor of the enzyme. Almost all of 4'- and 5'-phenols appeared as conjugates with glucuronic acid and/or sulphuric acid. These findings indicated that in man triethoxybenzoylpropionate was largely conjugated with glucuronic acid and in part underwent deethylation followed by conjugation for elimination mainly in urine.

Benzoates↗
PubMed1983

Two distinct classes of polyuronide from the cell walls of a dimorphic fungus, Mucor rouxii.

Polyuronides were extracted from purified yeast and mycelial walls of Mucor rouxii by sequential treatments with lithium chloride and potassium hydroxide and were fractionated by ion-exchange chromatography on DEAE-Sephadex. Two polymers (I and II) of different acidity were found in both wall types. Polymer I contained D-glucuronic acid, L-fucose, D-mannose, and much smaller amounts of D-galactose. Yeast and mycelial polymer I had similar uronic acid contents but differed in their neutral sugar compositions and molecular weights. Polymer II from both cell types contained largely D-glucuronic acid and had similar molecular weights. On partial acid hydrolysis, both polymers I and II gave rise to insoluble glucuronans which appeared to be homopolymeric. One-third of the total uronosyl residues of polymer I, and almost all of the uronosyl residues of polymer II, were present in homopolymeric segments. However, homopolymers derived from polymers I and II may not be identical.

Cell Wall↗
PubMed1997

Application of photoaffinity labeling with [11,12-3H]all-trans-retinoic acid to characterization of rat liver microsomal UDP-glucuronosyltransferase(s) with activity toward retinoic acid.

[3H]All-trans-retinoic acid has been shown to be an effective photoaffinity label for microsomal UDP-glucuronosyltransferases. Labeling of rat liver microsomal proteins with [3H]all-trans-retinoic acid and [32P]5-azido-UDP-glucuronic acid has shown that at least one protein in the 50-56 kDa mass range encompassing the UDP-glucuronosyltransferases photoincorporated both probes. The fraction of solubilized microsomal protein eluted from a UDP-hexanolamine affinity column with 50 microM UDP-glucuronic acid contained two protein bands, both of which photoincorporated [3H] all-trans-retinoic acid and were detected on Western blot by anti-UDP-glucuronosyltransferase antibodies. Enzymatic glucuronidation activity toward atRA in the same fraction was enriched five-fold over that of native or solubilized microsomes.

Affinity Labels↗
PubMed2006

Identification of human UDP-glucuronosyltransferase responsible for the glucuronidation of niflumic acid in human liver.

PURPOSE: To assess the uridine diphosphate (UDP)-glucuronosyltransferase (UGT) isozymes involved in the glucuronidation of niflumic acid in human liver. METHODS: The glucuronidation activity of niflumic acid was determined in liver microsomes and recombinant UGT isozymes by incubation of niflumic acid with UDP-glucuronic acid (UDPGA). RESULTS: Incubation of niflumic acid with liver microsomes and UDPGA produced one peak, which was identified as a glucuronide from mass spectrometric analysis. A study involving a panel of recombinant human UGT isozymes showed that glucuronidation activity was highest in UGT1A1 among the isozymes investigated. The glucuronidation in human liver microsomes (HLMs) followed Michaelis-Menten kinetics with a Km value of 16 microM, which is similar to that found with recombinant UGT1A1. The glucuronidation activity of niflumic acid in microsomes from eight human livers significantly correlated with UGT1A1-catalyzed estradiol 3beta-glucuronidation activity (r=0.78, p<0.05). Beta-estradiol inhibited niflumic acid glucuronidation with an IC50 of 25 microM in HLMs, comparable to that for UGT1A1. CONCLUSIONS: These findings indicate that UGT1A1 is the main isozyme involved in the glucuronidation of niflumic acid in the human liver.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1986

Biosynthesis of D-glucaric acid in mammals: a free-radical mechanism?

In the presence of iron salts and hydrogen peroxide, D-glucuronic acid was converted into D-glucaric acid. The reaction was strongly inhibited by free-radical scavengers and is ascribed to the action of the hydroxyl radical. The formation of D-glucarate was dependent upon pH and occurred in the presence of some iron-complexing agents. The first product of oxidation was a lactone that was a strong inhibitor of beta-D-glucuronidase and assumed to be D-glucaro-1,5-lactone. Microsomal preparations in the presence of NADPH also produced D-glucarate from D-glucuronic acid, presumably due to formation of hydrogen peroxide, and the product was an inhibitor of beta-D-glucuronidase. Superoxide did not produce D-glucarate from D-glucuronate. The cytochrome P450 system is more likely than "glucuronolactone dehydrogenase" to be responsible for the production of D-glucaric acid in vivo.

Aldehyde Dehydrogenase↗
PubMedDate not supplied

Furosemide 1-O-acyl glucuronide. In vitro biosynthesis and pH-dependent isomerization to beta-glucuronidase-resistant forms.

A biosynthetic acyl-type glucuronic acid conjugate of furosemide was isolated from in vitro incubation of pregnenolone-16 alpha-carbonitrile-induced rat liver microsomes containing UDP-glucuronyltransferase activity, furosemide, and UDP-glucuronic acid. Furosemide 1-O-acyl glucuronide (FG) was specifically hydrolyzed by beta-glucuronidase (BG) and was also labile to alkaline hydrolysis. FG concentration decreased at an apparent first order rate when incubated at 37 degrees C in buffer solution of pH values greater than 6.0 with only moderate hydrolysis of the conjugate at pH values less than 8.5. Formation of rearrangement forms of FG that were resistant to BG but labile to alkaline hydrolysis accounted for most of the disappearance of FG at this pH range. Radiochemical labeling of the conjugate with either 14C-furosemide or 14C-UDP-glucuronic acid was detected in the BG-resistant isomerization products of FG as they were separated by HPLC. The structure of FG and its isomerization products was further verified by negative ion thermospray liquid chromatography/mass spectrometry. The abundant (M - 1)-ion at mass 505, the aglycone fragment at m/z 329, and the characteristic sugar fragment ion of mass 175 were found in the spectra of FG and three additional isomers. An ion at m/z 221 was noted only in the case of the parent conjugate and thus may prove to be a characteristic ion for 1-O-acyl-linked glucuronides under negative ion thermospray. In vivo as well as in vitro rearrangement of FG to BG-resistant forms might affect the results of furosemide disposition studies which use BG hydrolysis to determine FG formation.

Animals↗
PubMed1985

Major urinary metabolites in hamsters and rats treated with N-nitroso(2-hydroxypropyl)(2-oxopropyl)amine.

Rats and hamsters were administered a single dose of N-[1-14C]nitroso(2-hydroxypropyl)(2-oxopropyl)amine (HPOP), and their urinary metabolites were examined at various time intervals. In both species, urinary excretion of radiolabeled metabolites reached a plateau at 6 h following injection. At this time, 35 and 28% of the total dose was found in the urine of rats and hamsters, respectively. Separation by liquid chromatography and subsequent characterization by nuclear magnetic resonance, gas chromatography-mass spectroscopy, and infrared showed that the major metabolites in rat urine were HPOP, N-nitrosobis(2-hydroxypropyl)amine (BHP), and their glucuronic acid conjugates. The conjugates accounted for 30 and 9%, while free HPOP and BHP accounted for 42 and 16% of the total metabolites, respectively. Hamster urine, on the other hand, contained free HPOP, BHP, their glucuronic acid conjugates, and a sulfate ester of HPOP not found in rat urine. Six h following administration of HPOP, hamster urine contained BHP, BHP glucuronide, HPOP, HPOP glucuronide, and HPOP sulfate ester at levels of 35, 9, 16, 9, and 14%, respectively. These data suggest that hamsters reduce HPOP to BHP more efficiently than rats, while rats are more effective in forming their glucuronic acid conjugates. Hamsters differ significantly from rats in their capacity to form and excrete the sulfate ester of HPOP.

Animals↗
PubMed1994

Molecular characterization of hasA from an operon required for hyaluronic acid synthesis in group A streptococci.

The mechanism by which group A streptococci produce the antiphagocytic hyaluronate (hyaluronic acid) capsule is incompletely understood. Enzymes known to be essential for synthesis of this polysaccharide include the membrane-associated hyaluronate synthase as well as those required for production of the substrate sugars UDP-N-acetylglucosamine and UDP-glucuronic acid. In this study, a Tn916 insertion that inactivates hyaluronate synthetic activity was localized to a gene designated hasA in the hyaluronic acid synthesis operon. This gene has recently been preliminarily identified as the group A streptococcal hyaluronate synthase. The DNA sequence and transcription start site of hasA were determined, and the predicted HasA protein was shown to have characteristics of a membrane protein. Amino acid sequence homology suggests that HasA is related to a family of proteins involved in polysaccharide production and cell differentiation. Finally, in addition to the loss of hyaluronate synthase activity, the hasA::Tn916 insertion was demonstrated to correlate with a loss of UDP-glucuronic acid dehydrogenase activity. These results suggest that the genes required for hyaluronate synthase activity and production of the UDP-glucuronic acid substrate are transcribed as a unit in group A streptococci.

Amino Acid Sequence↗
PubMed1990

[A comparative study of the effects of nicotinamide and diethylnicotinamid on hepatic monooxygenase, glucuronyl and glutathione conjugating systems].

The nicotinamide administration to rats (50 mg/kg, subcutaneously, over 5 days) increased the concentration of liver cytochrome b5, the activities of cytosol and microsomal glutathione S-transferase, UDP-glucuronosyltransferase and urinary excretion of bound glucuronic acid by 26.7, 33.1, 33.3, 53.0 and 31.0%, respectively. The chloral hydrate-induced sleep time in mice was reduced by 65%. Under similar experimental conditions the administration of equimolar amounts of diethylamide of nicotinic acid (75 mg/kg) exerted a more pronounced enzyme-stimulating effect. The cytochrome P-450 concentration, the activities of cytosol and microsomal glutathione S-transferase, UDP-glucuronosyltransferase as well as the sulphobromophthalein elimination from blood plasma and urinary excretion of bound glucuronic acid were increased by 37.0, 33.1, 54.6, 80.5, 24.5 and 49.0%, whereas the chloral hydrate-induced sleep time decreased by 75%. The nicotinamide and diethylamide of nicotinic acid stimulating effects on xenobiotic biotransformation in rat liver are assumed to be due to enhanced NADPH, glutathione and UDP-glucuronic acid biosynthesis as well as their antioxidant properties.

Animals↗
PubMed1994

Analysis of p-nitrophenol glucuronidation in hepatic microsomes from lactating rats.

In the present study, hepatic p-nitrophenol glucuronidation was analyzed comparatively in virgin female, lactating mother and nonlactating mother rats (the last two groups 19-21 days post-partum). Enzyme assays were performed in native and activated microsomal suspensions. Activation was achieved either by including UDP-N-acetylglucosamine in the incubation mixtures or by preincubating native microsomes with optimal concentrations of Triton X-100 or palmitoyl-lysophosphatidylcholine. When UDP-N-acetylglucosamine was used as activator, enzyme activity increased in both lactating (about 80% increment) and nonlactating mothers (about 30% increment) as compared with virgin females. From an analysis of the degree of activation by Triton X-100 and palmitoyl-lysophosphatidylcholine, it can be inferred that the pregnancy-delivery event decreased the latency of UDP-glucuronosyltransferase activity that was detectable even 3 weeks post-partum, irrespective of whether suckling newborns were or were not kept with their mothers (lactating and nonlactating mothers, respectively). The estimation of apparent Vmax toward UDP-glucuronic acid in palmitoyl-lysophosphatidylcholine-activated microsomes, which allows an estimation of the amount of the enzyme, showed that lactation increased the number of catalytic units (about 40%). Hepatic UDP-glucuronic acid content was 70% higher in lactating rats than in other groups. The lipid composition and membrane fluidity (using 1,6-diphenyl-1,3,5-hexatriene as probe) were also analyzed in microsomes from all groups. A significant decrease in the unsaturation index that correlated with the rigidization of microsomal membranes was consistent with the changes in the degree of enzyme latency observed in lactating and nonlactating mothers. In conclusion, lactating rats exhibited enhanced p-nitrophenol UDP-glucuronosyltransferase activity as well as an increase in the hepatic content of UDP-glucuronic acid. These findings and the fact that lactation increased the liver to body weight ratio emphasize the role of the liver in the metabolism of planar phenolic derivatives in these circumstances.

Animals↗
PubMed2000

Structure of an acidic O-specific polysaccharide of the marine bacterium Pseudoalteromonas sp. KMM 634.

An acidic O-specific polysaccharide containing D-glucuronic acid (D-GlcA), 2,3-diacetamido-2,3-dideoxy-D-glucuronic acid (D-GlcNAc3NAcA), 2,3-diacetamido-2,3-dideoxy-D-mannuronoyl-L-alanine (D-ManNAc3NAcA6Ala), and 2-acetamido-2,4, 6-trideoxy-4-[(S)-3-hydroxybutyramido]-D-glucose (D-QuiNAc4NAcyl) was obtained by mild acid degradation of the lipopolysaccharide of the bacterium Pseudoalteromonas sp. KMM 634 followed by gel-permeation chromatography. The polysaccharide was cleaved selectively with a new solvolytic agent, trifluoromethanesulfonic acid, to give a disaccharide and a trisaccharide with D-GlcNAc3NAcA at the reducing end. The borohydride-reduced oligosaccharides and the initial polysaccharide were studied by GLC-MS and 1H- and 13C-NMR spectroscopy, and the following structure of the linear tetrasaccharide repeating unit of the polysaccharide was established: -->3)-alpha-D-QuipNAc4Ac4NAcyl-(1-->4)-beta-D-ManpNAc3NAcA6Ala+ ++-(1-->4)-b eta-D-GlcpNAc3NAc3NAcA-(1-->4)-beta-D-GlcpA-(1-->.

Carbohydrate Sequence↗