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1.
The primary structure of teichuronic acid in Bacillus subtilis AHU 1031   总被引:3,自引:0,他引:3  
Structural studies were carried out on the acidic polysaccharide fraction obtained from lysozyme digest of the cell walls of Bacillus subtilis AHU 1031. The polysaccharide fraction contained N- acetylmannosaminuronic acid ( ManNAcA ), N-acetylglucosamine (GlcNAc), glucose, glycerol and phosphorus in a molar ratio of 2:2:4:1:1, together with glycopeptide components. The results of analyses involving Smith degradation, chromium trioxide oxidation, methylation and proton magnetic resonance spectroscopy led to the conclusion that the backbone chain of the polysaccharide has the repeating unit----6)Glc(alpha 1----3/4) ManNAcA (beta 1----4)GlcNAc(beta 1----. About 50% of the N-acetylglucosamine residues in the backbone chain seem to be substituted at C-3 by the glycosidic branches, glycerol phospho-6-glucose, while the other half seem to be substituted by glucose.  相似文献   

2.
Teichoic acid-glycopeptide complexes were isolated from lysozyme digests of the cell walls of Bacillus coagulans AHU 1631, AHU 1634, and AHU 1638, and the structure of the teichoic acid moieties and their linkage regions was studied. On treatment with hydrogen fluoride, each of the complexes gave a hexosamine-containing disaccharide, which was identified to be glucosyl(beta 1----4)N-acetylglucosamine, in addition to dephosphorylated repeating units of the teichoic acids, namely, galactosyl(alpha 1----2)glycerol and either galactosyl(alpha 1----2)[glucosyl(alpha 1----1/3)]glycerol (AHU 1638) or galactosyl(alpha 1----2)[glucosyl(beta 1----1/3)]glycerol (AHU 1631 and AHU 1634). From the results of Smith degradation, methylation analysis, and partial acid hydrolysis, the teichoic acids from these strains seem to have the same backbone chains composed of galactosyl(alpha 1----2)glycerol phosphate units joined by phosphodiester bonds at C-6 of the galactose residues. The presence of the disaccharide, glucosyl(beta 1----4)N-acetylglucosamine, in the linkage regions between teichoic acids and peptidoglycan was confirmed by the isolation of a disaccharide-linked glycopeptide fragment from each complex after treatment with mild alkali and of a teichoic acid-linked saccharide from each cell wall preparation after treatment with mild acid. Thus, it is concluded that despite structural differences in the glycosidic branches, the teichoic acids in the cell walls of the three strains are linked to peptidoglycan through a common linkage saccharide, glucosyl (beta 1----4) N-acetylglucosamine.  相似文献   

3.
The structure of polysaccharide prepared by lysozyme digestion from the cell wall of Propionibacterium acnes strain C7 was examined. The polysaccharide fraction was composed of glucose, galactose, mannose, galactosamine, and diaminomannuronic acid in a molar ratio of 1:1:0.3:1:2. By Smith degradation of the polysaccharide, diaminouronic acid-containing fractions were obtained, and the configuration of diaminouronic acid was identified as 2,3-diacetamido-2,3-dideoxymannuronic acid [Man(NAc)2A] by means of 1H-NMR and 13C-NMR spectroscopic analyses. The results of analyses involving methylation and partial acid hydrolysis led to the conclusion that the polysaccharide has the repeating unit----6)Gal(alpha 1----4)Man(NAc)2A(beta 1----6)Glc(alpha 1----4)Man(NAc)2A (beta 1----3)GalNAc(beta 1--. In addition, a portion of the galactose residues were substituted at C-4 by alpha 1----2 linked mannotriose.  相似文献   

4.
Structural studies were carried out on the teichoic acids in cell walls of Listeria monocytogenes serotypes 3a, 4b, 4f, 6, and 7. The structure of the dephosphorylated repeating units, obtained by treatment with 46% hydrogen fluoride or alkaline hydrolysis, was examined by methylation analysis, acetolysis, and 1H-NMR spectroscopy. The results of Smith degradation of the teichoic acids and 13C-NMR spectroscopy led to the following most likely structures of the repeating units of the teichoic acids:----1-[N-acetylglucosaminyl(alpha 1----4)]ribitol-5-phosphate----for serotype 3a,----4-[galactosyl(alpha 1----6)][glucosyl(beta 1----3)]N -acetylglucosaminyl(beta 1----2)ribitol-5-phosphate----for serotype 4b,----4-[galactosyl(alpha 1----6)][N -acetylglucosaminyl(alpha 1----3)]N-acetylglucosaminyl(beta 1----2)ribitol -5-phosphate----for serotype 4f,----4-N-acetylglucosaminyl(beta 1----4)ribitol -5-phosphate----for serotype 6, and----1-ribitol-5-phosphate----for serotype 7. About 40% of the repeating units of the teichoic acid from serotype 4f were not substituted at C-3 of beta-N-acetylglucosaminyl residues.  相似文献   

5.
The structure of the linkage unit between ribitol teichoic acid and peptidoglycan in the cell walls of Listeria monocytogenes EGD was studied. A teichoic-acid--glycopeptide preparation isolated from lysozyme digests of the cell walls of this strain contained mannosamine, glycerol, glucose and muramic acid 6-phosphate in an approximate molar ratio of 1:1:2:1, together with large amounts of glucosamine and other components of teichoic acid and glycopeptides. A teichoic-acid-linked sugar preparation, obtained by heating the cell walls at pH 2.5, also contained glucosamine, mannosamine, glycerol and glucose in an approximate molar ratio of 25:1:1:2. Part of the glucosamine residues were shown to be involved in the linkage unit. Thus, on mild alkaline hydrolysis, the teichoic-acid-linked sugar preparation gave a disaccharide characterized as N-acetylmannosaminyl(beta 1----4)-N-acetylglucosamine [ManNAc(beta 1----4)GlcNAc] in addition to the ribitol teichoic acid moiety, whereas the teichoic-acid - glycopeptide was separated into disaccharide-linked glycopeptide and the ribitol teichoic acid moiety by the same procedure. Furthermore, Smith degradation of the cell walls gave a characteristic fragment, EtO2-P-Glc(beta 1----3)Glc(beta 1----1/3)Gro-P-ManNAc(beta 1----4)GlcNAc (where EtO2 = 1,2-ethylenediol and Gro = glycerol). The results lead to the conclusion that in the cell walls of this organism, the ribitol teichoic acid chain is linked to peptidoglycan through a novel linkage unit, Glc(beta 1----3)Glc(beta 1----1/3)Gro-P-(3/4)ManNAc-(beta 1----4)GlcNAc.  相似文献   

6.
Lipopolysaccharides were isolated from the phenol layer on aqueous phenol extraction of cells of Pseudomonas aeruginosa O11 (Lányi classification), strains 170021 and 170040. On mild acid degradation of the lipopolysaccharides, with the subsequent gel-filtration on Sephadex G-50, neutral O-specific polysaccharides made up of 6-deoxysugars alone were obtained. Two 2-acetamido-2,6-dideoxy-L-galactose (LFucNAc), 2-acetamido-2,6-dideoxy-D-glucose (DQuiNAc) and L-rhamnose (LRha) residues were found to be the components of the strain 170021 polysaccharide repeating units; those of strain 170040 contained the same monosaccharides, but, instead of 2-acetamido-2,6-dideoxy-D-glucose residue, that of 2-acetamido-2,6-dideoxy-D-galactose (DFucNAc) was present. On the basis of the 13C nuclear magnetic resonance data, methylation analysis and three successive Smith degradations the following structures were determined for the polysaccharide repeating units: strain 170021----2) LRha(alpha 1----3)LFucNAc(alpha 1----3)LFucNAc(alpha 1----3)DQuiNAc(beta 1----; strain 170040,----2)LRha(alpha 1----3)LFucNAc-(alpha 1----3)LFucNAc(alpha 1----3)DFucNAc(beta 1----; differing from one another by configuration of C-4 of 2-acetamido-2,6-dideoxy-D-hexopyranose only.  相似文献   

7.
S Kaya  K Yokoyama  Y Araki    E Ito 《Journal of bacteriology》1984,158(3):990-996
The structure of teichoic acid-glycopeptide complexes isolated from lysozyme digests of cell walls of Bacillus subtilis (four strains) and Bacillus licheniformis (one strain) was studied to obtain information on the structural relationship between glycerol teichoic acids and their linkage saccharides. Each preparation of the complexes contained equimolar amounts of muramic acid 6-phosphate and mannosamine in addition to glycopeptide components and glycerol teichoic acid components characteristic of the strain. Upon treatment with 47% hydrogen fluoride, these preparations gave, in common, a hexosamine-containing disaccharide, which was identified as N- acetylmannosaminyl (1----4) N-acetylglucosamine, along with large amounts of glycosylglycerols presumed to be the dephosphorylated repeating units of teichoic acid chains. The glycosylglycerol obtained from each bacterial strain was identified as follows: B. subtilis AHU 1392, glucosyl alpha (1----2)glycerol; B. subtilis AHU 1235, glucosyl beta(1----2) glycerol; B. subtilis AHU 1035 and AHU 1037, glucosyl alpha (1----6)galactosyl alpha (1----1 or 3)glycerol; B. licheniformis AHU 1371, galactosyl alpha (1----2)glycerol. By means of Smith degradation, the galactose residues in the teichoic acid-glycopeptide complexes from B. subtilis AHU 1035 and AHU 1037 and B. licheniformis AHU 1371 were shown to be involved in the backbone chains of the teichoic acid moieties. Thus, the glycerol teichoic acids in the cell walls of five bacterial strains seem to be joined to peptidoglycan through a common linkage disaccharide, N- acetylmannosaminyl (1----4)N-acetylglucosamine, irrespective of the structural diversity in the glycosidic branches and backbone chains.  相似文献   

8.
Structural studies were carried out on the O-polysaccharide fraction obtained from the lipopolysaccharide of Pseudomonas aeruginosa IID 1012, the standard strain of Homma serogroup K, by mild acid treatment. The O-polysaccharide was composed of L-rhamnose, N-acetyl-D-quinovosamine, and N-acetyl-D-galactosaminuronic acid. The results from analysis of fragments obtained by acid hydrolysis and Smith degradation of the O-polysaccharide, together with data on methylation analysis and nuclear magnetic resonance spectroscopic measurement of the polysaccharide, led to the most likely structure of the repeating units of the polymer chain, ----4)D-GalNAcA(alpha 1----3)D-QuiNAc(beta 1----2)L-Rha(alpha 1----3)L-Rha(alpha 1----, in which about 20% of the N-acetylgalactosaminuronic acid residues were in an amide form and about 75% of the same residues were O-acetylated at C-3.  相似文献   

9.
Pneumococcal lipoteichoic acid was extracted and purified by a novel, quick and effective procedure. Structural analysis included methylation, periodate oxidation, Smith degradation, oxidation with CrO3, and fast-atom-bombardment mass spectrometry. Hydrolysis with 48% (by mass) HF and subsequent phase partition yielded the lipid anchor (I), the dephosphorylated repeating unit of the chain (II) and a cleavage product of the latter (III). The proposed structures are: (I) Glc(beta 1----3)AATGal(beta 1----3)Glc(alpha 1----3)acyl2Gro, (II) Glc(beta 1----3)AATGal(alpha 1----4)GalNAc(alpha 1----3)GalNAc(beta 1----1)ribitol and (III) Glc(beta 1----3)AATGal(alpha 1----4)GalNAc(alpha 1----3)GalNAc, where AATGal is 2-acetamido-4-amino-2,4,6-trideoxygalactose, and all sugars are in the pyranose form and belong to the D-series. Alkaline phosphodiester cleavage of lipoteichoic acid, followed by treatment with phosphomonoesterase, resulted in the formation of II and IV, with IV as the prevailing species: [sequence: see text] The linkage between the repeating units was established as phosphodiester bond between ribitol 5-phosphate and position 6 of the glucosyl residue of adjacent units. The chain was shown to be linked to the lipid anchor by a phosphodiester between its ribitol 5-phosphate terminus and position 6 of the non-reducing glucosyl terminus of I. The lipoteichoic acid is polydisperse: the chain length may vary between 2 and 8 repeating units and variations were also observed for the fatty acid composition of the diacylglycerol moiety. Preliminary results suggest that repeating units II and IV are enriched in separate molecular species. All species were associated with Forssman antigenicity, albeit to a various extent when related to the non-phosphocholine phosphorus. Owing to its unique structure, the described macroamphiphile may be classified as atypical lipoteichoic acid.  相似文献   

10.
The minor teichoic acid linked to glycopeptide was isolated from lysozyme digests of Bacillus coagulans AHU 1631 cell walls, and the structure of the teichoic acid moiety and its junction with the peptidoglycan were studied. Hydrolysis of the teichoic-acid--glycopeptide complex with hydrogen fluoride gave a nonreducing oligosaccharide composed of glucose, galactose and glycerol in a molar ratio of 3:1:1 which was presumed to be dephosphorylated repeating units of the polymer chain. From the results of structural analysis involving NaIO4 oxidation, methylation and acetolysis, the above fragment was characterized as glucosyl(beta 1----3)glucosyl(beta 1----6)galactosyl(beta 1----6)glucosyl(alpha 1----1/3)glycerol. In addition, the Smith degradation of the complex yielded a phosphorus-containing fragment identified as glycerol-P-6-glucosyl(beta 1----1/3)glycerol. These results led to the most likely structure for the repeating units of the teichoic acid, -6[glucosyl(beta 1----3)]glucosyl(beta 1----6)galactosyl(beta 1----6)glucosyl(alpha 1----1/3)glycerol-P-. The minor teichoic acid, just like the major teichoic acid bound to the linkage unit, was released by heating the cell walls at pH 2.5. The mild alkaline hydrolysis of the minor teichoic acid after reduction with NaB3H4 gave labeled saccharides characterized as glucosyl(beta 1----6)galactitol and glucosyl(beta 1----3)glucosyl(beta 1----6)galactitol, together with a large amount of the unlabeled repeating units of the teichoic acid chain. Thus, the minor teichoic acid chain is believed to be directly linked to peptidoglycan at the galactose residue of the terminal repeating unit without a special linkage sugar unit.  相似文献   

11.
Structural studies were carried out on the O-polysaccharide fraction obtained by mild acid treatment of the lipopolysaccharide from Pseudomonas aeruginosa IID 1009 (ATCC 27585). The O-polysaccharide was composed of L-rhamnose, N-acetyl-D-quinovosamine, and N-acetyl-L-galactosaminuronic acid in a molar ratio of 1:1:1. The results from analysis of fragments obtained by hydrogen fluoride hydrolysis of O-polysaccharide, together with data on methylation analysis and nuclear magnetic resonance spectroscopic analysis, led to the most likely structure of the repeating units of the polymer chain ----4)L-GalNAcA(alpha 1----3)D-QuiNAc(alpha 1----3)L-Rha(alpha 1----, in which about 70% of the rhamnose residues were O-acetylated at C-2. This structure coincides with that of the repeating unit of Lanyi 02 a,b polysaccharides.  相似文献   

12.
Fragmentation of the heparan sulfate chains from bovine glomerular basement membrane (GBM) by hydrazine/nitrous acid treatment followed by NaB3H4-reduction yielded a mixture of six sulfated disaccharides containing D-glucuronic (GlcUA) or L-iduronic acid (IdUA) and terminating in 2,5-anhydro[3H]mannitol (AnManH2), in addition to the nonsulfated component GlcUA beta 1----4AnManH2. Among these products two novel disaccharide units were identified as IdUA alpha 1----4AnManH2(3-SO4) and IdUA(2-SO4)alpha 1----4AnManH2(3-SO4); these accounted for 22% of the total sulfated species indicating that there are 2-3 residues of 3-O-sulfated glucosamine/heparan sulfate chain. The disulfated disaccharide was shown through its release by direct nitrous acid treatment to be situated in a GlcNSO3-IdUA(2-SO4)-GlcNSO3(3-SO4) sequence which is distinct from that in which 3-O-sulfated glucosamine is located in the antithrombin-binding region of heparins. Analyses of heparan sulfate from lens capsule, a nonvascular basement membrane, indicated the absence of sequences containing 3-O-sulfated glucosamine, although otherwise the sulfated disaccharides produced by hydrazine/nitrous acid/Na-B3H4 treatment (GlcUA beta 1----4AnManH2(6-SO4), IdUA alpha 1----4AnManH2(6-SO4), IdUA(2-SO4)alpha 1----4AnManH2 and IdUA(2-SO4)alpha 1----4AnManH2(6-SO4] were the same as from GBM. Examination of the GBM heparan sulfate domains after nitrous acid treatment indicated that the O- as well as N-sulfate groups are clustered in an iduronic acid-rich 10-disaccharide peripheral segment, while the internal region (approximately 20 disaccharides) is composed primarily of repeating GlcUA beta 1----4GlcNAc units. The localization of chain diversity to the outer region may facilitate interactions of the heparan sulfate with other macromolecular components.  相似文献   

13.
The isolation and analysis of the cell wall and the polysaccharide-glycopeptide complexes of Bifidobacterium adolescentis YIT4011 are presented. Polysaccharide-glycopeptide complexes, PS-GP1 and PS-GP2, were solubilized from the cell wall by treatment with N-acetylmuramidase. PS-GP1 and PS-GP2 were found to be composed of glucose, 6-deoxytalose and a small amount of glycopeptide. The products of Smith degradation of the PS-GPs had no glucose-containing fraction, but were composed of 1,2/1,3-linked 6-deoxytalose. Furthermore, a second Smith degradation of this fraction yielded trisaccharide-glyceraldehyde. These results and methylation analysis led to the conclusion that PS-GP1 or 2 has a repeating unit of----3)6dTal(beta 1----3)6dTal(beta 1----3)6dTal(beta 1----2)-6dTal(alpha 1----2)6dTal(alpha 1----2)6dTal(alpha 1-, and that glucose residues are linked to position C-3 of the 2-O-substituted 6-deoxytalose residues.  相似文献   

14.
Structural studies were carried out on a teichuronic acid isolated from a mild acid extract of Bacillus subtilis AHU 1219 cell walls. The teichuronic acid contained D-glucuronic acid, D-glucose, D-galactose, L-serine and L-threonine in a molar ratio of 1:1:1:0.5:0.5. Results of analyses of the polysaccharide by Smith degradation, methylation and 1H-NMR and 13C-NMR spectroscopy, in combination with data on analyses of oligosaccharides obtained by partial acid hydrolysis and alkaline hydrolysis of the polymer, led to the most likely structure for the repeating unit, ----4)(L-Ser/L-Thr)-D-GlcA(beta 1----3)-D-Glc(beta 1----4)-D-Gal(alpha 1----. In each unit, either amino acid is linked to the glucuronic acid residue through an amide bond.  相似文献   

15.
Band-3 glycoprotein was purified from human blood-group-A erythrocyte membranes by selective solubilization and gel chromatography on Sepharose 6B in the presence of sodium dodecyl sulphate. The purified glycoprotein was subjected to hydrazinolysis in order to release the carbohydrate moiety. The released oligosaccharides were N-acetylated and applied to a column of DEAE-cellulose. Most of the band-3 oligosaccharides obtained were found to be free of sialic acids. When this neutral fraction was subjected to gel chromatography on a column of Sephadex G-50, two broad peaks were observed indicating that the band-3 glycoprotein was heterogeneous in the size of the oligosaccharide moieties. All fractions from gel chromatography were found to contain galactose, mannose, N-acetylglucosamine and fucose. The higher-molecular-weight (mol.wt. 3000-8000) peak consisted of fucose, mannose, galactose, N-acetylglucosamine and N-acetylgalactosamine in a molar proportion of 1.6:3.0:8.4:10.5:0.2. Most of these oligosaccharides were digested with a mixture of beta-galactosidase and beta-N-acetylhexosaminidase after alpha-L-fucosidase treatment to give a small oligosaccharide with the structure alpha Man2-beta Man-beta GlcNAc-GlcNAc. Methylation studies and limited degradation by nitrous acid deamination showed that the oligosaccharides contained the repeating disaccharide Gal beta 1----4GlcNAc beta 1----3, with branching points at C-6 of some of the galactose residues. These results indicate that a major portion of the band-3 oligosaccharide has a common core structure, with heterogeneity in the numbers of the repeating disaccharides, and contains fucose residues both in the peripheral portion and in the core portion. Haemagglutination tests were also carried out to determine the blood-group specificities of the glycoprotein and the results demonstrated the presence of both blood-group-H and I antigenic activities.  相似文献   

16.
Fucosyl residues in the alpha 1----3 linkage to N-acetylglucosamine (Fuc alpha 1----3GlcNAc) on oligosaccharides of glycoproteins and glycolipids have been detected in certain human tumors and are developmentally expressed (reviewed in Foster, C. S., and Glick, M. C. (1988) Adv. Neuroblastoma Res. 2, 421-432). In order to understand control mechanisms for the biosynthesis of these fucosylated glycoconjugates, GDP-L-Fuc-N-acetyl-beta-D-glucosaminide alpha 1----3fucosyltransferase was purified from human neuroblastoma cells, CHP 134, utilizing either the immobilized oligosaccharide or disaccharide substrates. The enzyme, extracted from CHP 134 cells, was purified by DEAE- and SP-Sephadex chromatography and then by either immobilized substrate. alpha 1----3Fucosyltransferase was obtained in approximately 10% yield and was purified 45,000-fold from the cell extract. The kinetic properties of the enzyme showed an apparent KGDP-Fuc 43 microM, KGal beta 1----4GlcNAc 0.4 mM, KGal beta 1----4Glc 8.1 mM, and KFuc alpha 1----2Gal beta 1----4Glc 1.0 mM. Polyacrylamide gel electrophoresis of the affinity-purified enzyme showed two proteins which migrated, Mr = 45,000-40,000. The enzyme differed in substrate specificity, pH optimum, response to N-ethylmaleimide and ion requirements from the enzymes purified from human milk or serum. The inability of alpha 1----3fucosyltransferase to transfer to substrates containing NeuAc alpha 2----3 or alpha 2----6Gal is in contrast to the reports for the enzyme in other human tumors. This substrate specificity correlates with the oligosaccharide residues thus far defined on glycoproteins of CHP 134 cells since NeuAc and Fuc alpha 1----3GlcNAc have yet to be detected on the same oligosaccharide antenna. However, the enzyme transfers to Fuc alpha 1----2Gal beta 1----4GlcNAc/Glc with higher activity than the unfucosylated disaccharides, although neither alpha 1----2fucosyltransferase nor Fuc alpha 1----2 residues have been detected in CHP 134 cells. The different substrate specificities of alpha 1----3fucosyltransferase isolated from human tumors and normal sources leads to the suggestion that a family of alpha 1----3fucosyltransferases may exist and that they may be differentially expressed in human tumors.  相似文献   

17.
A novel phosphonoglycosphingolipid named SGL-I containing 3 mol of 2-aminoethylphosphonate residues was isolated from the skin of a sea gastropod, Aplysia kurodai. The saccharide moiety of the glycolipid was characterized as 4-O-methyl-GlcNAc alpha 1----4GalNAc alpha-1----3 [6'-O-(2-aminoethylphosphonyl)Gal alpha 1----2] (2-aminoethylphosphonyl----6)Gal beta 1----4(2-aminoethylphosphonyl----6) Glc beta 1----1-ceramide. The major aliphatic components of the ceramide portion were palmitic acid, stearic acid, octadeca-4-sphingenine, and anteisononadeca-4-sphingenine. This glycolipid is unique in containing 4-O-methyl-N-acetylglucosamine and 3 mol of 2-aminoethylphosphonate residues, one of which is attached to C-6 of glucose.  相似文献   

18.
Structures of the sugar chains of mouse immunoglobulin G   总被引:2,自引:0,他引:2  
The asparagine-linked sugar chains of mouse immunoglobulin G (IgG) were quantitatively liberated as radioactive oligosaccharides from the polypeptide portions by hydrazinolysis followed by N-acetylation, and NaB3H4 reduction. After fractionation by paper electrophoresis, lectin (RCA120) affinity high-performance liquid chromatography, and gel filtration, their structures were studied by sequential exoglycosidase digestion in combination with methylation analysis. Mouse IgG was shown to contain the biantennary complex type sugar chains. Eight neutral oligosaccharide structures, viz, +/- Gal beta 1----4GlcNAc beta 1----2Man alpha 1----6(+/- Gal beta 1---- 4GlcNAc beta 1----2Man alpha 1----3)Man beta 1----4GlcNAc beta 1----4(+/- Fuc alpha 1----6)GlcNAc, were found after the sialidase treatment. The molar ratio of the sugar chains with 2,1, and 0 galactose residues was 2:5:3. The galactose residue in the monogalactosylated sugar chains was distributed on Man alpha 1----3 and Man alpha 1----6 sides in the ratio of 1:3. The oligosaccharides were almost wholly fucosylated and contained no bisecting N-acetylglucosamine which is present in human, rabbit, and bovine IgGs.  相似文献   

19.
GalNAc beta 1----3 terminated glycosphingolipids of human erythrocytes   总被引:4,自引:0,他引:4  
Nonacid glycosphingolipids with 4 to 10 sugar residues isolated from pooled erythrocytes of blood group O donors have been efficiently separated as peracetylated derivatives on silicic acid. This procedure enabled a quantitative estimate of individual compounds and also revealed several GalNAc beta 1----3 terminated structures. The structural characterization of these glycolipids with 1H-NMR spectroscopy, direct inlet mass spectrometry, gas chromatography, and gas chromatography-mass spectrometry identified the compounds as GalNAc beta 1----3Gal alpha 1----4Gal beta 1----4Glc beta 1----1-N-acetyl sphingosine and GalNAc beta 1----3Gal alpha 1----4Gal beta 1----4Glc beta 1----1-N-acetyl phytosphingosine, GalNAc beta 1----3GalNAc beta 1----3Gal alpha 1----4Gal beta 1----4Glc beta 1----1 ceramide, and GalNAc beta 1----3Gal beta 1----4GlcNAc beta 1----3Gal beta 1----4Glc beta 1----1 ceramide.  相似文献   

20.
Three acidic polymer fractions with molecular masses of about 16 kDa, 35 kDa and 70 kDa were isolated from lysozyme digests of N-acetylated cell walls of Bacillus polymyxa AHU 1385 by ion-exchange chromatography and gel chromatography. These fractions, containing mannosamine, glucosamine and pyruvic acid in a molar ratio of about 1:1:1 together with glycopeptide components, were characterized as polysaccharide-linked glycopeptides with one, two and more polysaccharide chains. On the other hand, treatment of the cell walls with glycine/HC1 buffer, pH 2.5, at 100 degrees C for 10 min followed by separation of water-soluble products on ion-exchange chromatography gave three polysaccharide fractions, PS-I-III, which contained different amounts of pyruvic acid (0,0.6 and 0.9 residue/mannosamine residue) along with equimolar amounts of mannosamine and glucosamine. Pyruvate-free polysaccharides similar to PS-I were also obtained from PS-II, PS-III and polysaccharide-linked glycopeptides by treatment with 10 mM HC1 at 100 degrees C for 1 h. Results of analyses of these polysaccharide preparations by 1H-NMR and 13C-NMR measurement and methylation, together with data from characterization of fragments obtained by hydrogen fluoride hydrolysis, lead to the most likely structure, ----3)[4,6-O-(1-carboxyethylidene)]ManNAc(beta 1----4)GlcNac(beta 1----, for the acidic polysaccharide of this strain.  相似文献   

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