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Background: The α1,3‐galactosyltransferase gene‐knockout (GalT KO) mice are able to produce natural anti‐αGal antibodies apparently without any specific immunization. GalT KO mice are commonly used as a model immunological system for studying anti‐αGal responses to Gal‐positive xenografts in human. In this study, we compared the specificity of mouse and human αGal antibodies to realize the adequacy of the murine model. Methods: Using hapten‐specific affinity chromatography antibodies against Galα1‐3Galβ1‐4GlcNAcβ epitope were isolated from both human and GalT KO mice blood sera. Specificity of isolated antibodies was determined using a printed glycan array (PGA) containing 400 mammalian glycans and 200 bacterial polysaccharides. Results: The quantity of isolated specific anti‐Galα antibodies corresponds to a content of <0.2% of total Ig, which is an order of magnitude lower than that generally assumed for both human and murine peripheral blood immunoglobulin, with a high predominance of IgM over IgG (95% vs 5%). Analysis using a printed glycan array has demonstrated that (a) antibodies from both species bind not only the Galα1‐3Galβ1‐4GlcNAcβ epitope, but also unrelated glycans; (b) particularly, for human (but not mouse) antibodies the best binders appear to be bacterial polysaccharides; (c) the profile of mouse antibodies is broader, it is noteworthy that they recognize a variety of human blood group B epitopes and even glycans without the α‐galactosyl residue. Conclusions: We believe that the mouse model should be used cautiously in xenotransplantation experiments when the fine epitope specificity of antibodies is critical. [ABSTRACT FROM AUTHOR]

Bacteriophages recognize and bind to their hosts with the help of receptor-binding proteins (RBPs) that emanate from the phage particle in the form of fibers or tailspikes. RBPs show a great variability in their shapes, sizes, and location on the particle. Some RBPs are known to depolymerize surface polysaccharides of the host while others show no enzymatic activity. Here we report that both RBPs of podovirus G7C - tailspikes gp63.1 and gp66 - are essential for infection of its natural host bacterium E. coli 4s that populates the equine intestinal tract. We characterize the structure and function of gp63.1 and show that unlike any previously described RPB, gp63.1 deacetylates surface polysaccharides of E. coli 4s leaving the backbone of the polysaccharide intact. We demonstrate that gp63.1 and gp66 form a stable complex, in which the N-terminal part of gp66 serves as an attachment site for gp63.1 and anchors the gp63.1-gp66 complex to the G7C tail. The esterase domain of gp63.1 as well as domains mediating the gp63.1-gp66 interaction is widespread among all three families of tailed bacteriophages. [ABSTRACT FROM AUTHOR]

The C ampylobacter jejuni capsular polysaccharide is important for virulence and often contains a modified heptose. In strain ATCC 700819 (a.k.a. NCTC 11168), the modified heptose branches off from the capsular backbone and is directly exposed to the environment. We reported previously that the enzymes encoded by wca G, mlgh B and mlgh C are involved in heptose modification. Here, we show that inactivation of any of these genes leads to production of capsule lacking modified heptose and alters the transcription of other capsule modification genes differentially. Inactivation of mlgh B or mlgh C , but not of wca G , decreased susceptibility to bile salts and abrogated invasion of intestinal cells. All mutants showed increased sensitivity to serum killing, especially wca G ::cat, and had defects in colonization and persistence in chicken intestine, but did not show significant differences in adhesion, phagocytosis and intracellular survival in murine macrophages. Together, our findings suggest that the capsular heptose modification pathway contributes to bacterial resistance against gastrointestinal host defenses and supports bacterial persistence via its role in serum resistance and invasion of intestinal cells. Our data further suggest a dynamic regulation of expression of this pathway in the gastrointestinal tract. [ABSTRACT FROM AUTHOR]

d-fucofuranose (d-Fuc f) is a component of Escherichia coli O52 O antigen. This uncommon sugar is also the sugar moiety of the anticancer drug – gilvocarcin V produced by many streptomycetes. In E. coli O52, rmlA, rmlB, fcf1 and fcf2 were proposed in a previous study by our group to encode the enzymes of the dTDP-d-Fuc f (the nucleotide-activated form ofd-Fuc f) biosynthetic pathway. In this study, Fcf1 and Fcf2 from E. coli O52 were expressed, purified and assayed for their respective activities. Novel product peaks from enzyme-substrate reactions were detected by capillary electrophoresis and the structures of the product compounds were elucidated by electro-spray ionization mass spectrometry and nuclear magnetic resonance spectroscopy. Fcf1 was confirmed to be a dTDP-6-deoxy-d- xylo-hex-4-ulopyranose reductase for the conversion of dTDP-6-deoxy-d- xylo-hex-4-ulopyranose to dTDP-d-fucopyranose (dTDP-d-Fuc p), and Fcf2 a dTDP-d-Fuc p mutase for the conversion of dTDP-d-Fuc p to dTDP-d-Fuc f. The K m of Fcf1 for dTDP-6-deoxy-d- xylo-hex-4-ulopyranose was determined to be 0.38 mM, and of Fcf2 for dTDP-d-Fuc p to be 3.43 mM. The functional role of fcf1 and fcf2 in the biosynthesis of E. coli O52 O antigen were confirmed by mutation and complementation tests. This is the first time that the biosynthetic pathway of dTDP-d-Fuc f has been fully characterized. [ABSTRACT FROM AUTHOR]

Yersinia pseudotuberculosis O:2a harbours 6-deoxy-d- manno-heptose in its O-antigen. The biological function of 6-deoxyheptose and its role in virulence is unknown and its biosynthetic pathway has not been demonstrated experimentally. Here, we show that dmhA and dmhB are necessary for 6-deoxyheptose biosynthesis in Y. pseudotuberculosis. Their disruption resulted in the lack of 6-deoxyheptose in the O-unit and its replacement byd- glycero-d- manno-heptose, thus indicating relaxed specificity of the glycosyltransferases, polymerase and ligase involved in lipopolysaccharide synthesis. The dmhB mutant exhibited a lower content in ketooctonic acid (Ko)-containing core molecules and reduced ligation and polymerization of the O-unit. We also show that Tyr128 is essential for activity of DmhB, and that DmhB functions as an oligomer, based on the dominant negative effect of overexpression of DmhB Y128F in dmhA. Moreover, we demonstrate that 6-deoxyheptose is important for virulence-related functions of the outer membrane and its appendages in vitro, such as barrier function against bile salts, polymyxin and novobiocin, and flagella-mediated motility. Although both mutants colonized the mouse ceacum as well as the wild type, the dmhB mutant was impaired for colonization of the liver, suggesting that DmhB represents a potential therapeutic target. [ABSTRACT FROM AUTHOR]

An acidic branched O-polysaccharide was isolated by mild acid degradation of the lipopolysaccharide (LPS) of Proteus genomospecies 4 and studied by sugar and methylation analyses along with 1H and 13C NMR spectroscopy, including 2D COSY, TOCSY, ROESY and H-detected 1H,13C HSQC experiments. The following structure of the pentasaccharide repeating unit of the O-polysaccharide was established, which is unique among Proteus polysaccharide structures: where Qui3NAc stands for 3-acetamido-3,6-dideoxyglucose. Based on the O-polysaccharide structure and serological data, we propose classifying Proteus genomospecies 4 into a new, separate Proteus serogroup, O56. A weak cross-reactivity of Proteus genomospecies 4 antiserum with LPS of Providencia stuartii O18 and Proteus vulgaris OX2 was observed and is discussed in view of a similarity of the O-polysaccharide structures. Structural and serological investigations showed that Proteus genomospecies 5 and 6 should be classified into the existing Proteus serogroups O8 and O69, respectively. [ABSTRACT FROM AUTHOR]

The core structure of the lipopolysaccharide (LPS) isolated from a rough strain of the phytopathogenic bacteriumPseudomonas syringaepv.phaseolicola, GSPB 711, was investigated by sugar and methylation analyses, Fourier transform ion-cyclotron resonance ESI MS, and one- and two-dimensional1H-,13C- and31P-NMR spectroscopy. Strong alkaline deacylation of the LPS resulted in two core-lipid A backbone undecasaccharide pentakisphosphates in the ratio≈ 2.5 : 1, which corresponded to outer core glycoforms 1 and 2 terminated with eitherl-rhamnose or 3-deoxy-d-manno-oct-2-ulosonic acid (Kdo), respectively. Mild acid degradation of the LPS gave the major glycoform 1 core octasaccharide and a minor truncated glycoform 2 core heptasaccharide, which resulted from the cleavage of the terminal Kdo residues. The inner core ofP. syringaeis distinguished by a high degree of phosphorylation ofl-glycero-d-manno-heptose residues with phosphate, diphosphate and ethanolamine diphosphate groups. The glycoform 1 core is structurally similar but not identical to one of the core glycoforms of the human pathogenic bacteriumPseudomonas aeruginosa.The outer core composition and structure may be useful as a chemotaxonomic marker for theP. syringaegroup of bacteria, whereas a more conserved inner core structure appears to be representative for the whole genusPseudomonas. [ABSTRACT FROM AUTHOR]

The O-polysaccharide (O-antigen) was obtained from the lipopolysaccharide of Proteus myxofaciens , a Proteus strain producing copious amounts of slime, which was isolated from the gypsy moth larvae. The structure of the polysaccharide was studied by chemical analysis and 1 H and 13 C NMR spectroscopy, including 2D COSY, TOCSY, ROESY and H-detected 1 H,13 C HMQC experiments. It was found that the polysaccharide contains an amide of glucuronic acid (GlcA) with an unusual α-linked amino acid, N ε -[(R )-1-carboxyethyl]-l-lysine (2S,8R -alaninolysine, 2S,8R -AlaLys), and has a linear tetrasaccharide repeating unit of the following structure: &figfu1; This structure is unique among known bacterial polysaccharide structures. On the basis of these and serological data, it is proposed that P. myxofaciens be classified into a new Proteus serogroup, O60, of which this strain is the single representative. Structural and serological relatedness of P. myxofaciens to other AlaLys-containing O-antigens of Proteus and Providencia is discussed. [ABSTRACT FROM AUTHOR]

The O-specific polysaccharide of Citrobacter braakii PCM 1531 (serogroup O6) was isolated by mild acid hydrolysis of the lipopolysaccharide (LPS) and found to contain d-fucose, l-rhamnose, 4-deoxy-d-arabino -hexose and O-acetyl groups in molar ratios 2 : 1 : 1 : 1. On the basis of methylation analysis and 1 H and 13 C NMR spectroscopy data, the structure of the branched tetrasaccharide repeating unit of the O-specific polysaccharide was established. Using various serological assays, it was demonstrated that the LPS of strain PCM 1531 is not related serologically to other known 4-deoxy-d-arabino -hexose-containing LPS from Citrobacter PCM 1487 (serogroup O5) or C. youngae PCM 1488 (serogroup O36). Two other strains of Citrobacter , PCM 1504 and PCM 1505, which, together with strain PCM 1531, have been classified in serogroup O6, were shown to be serologically distinct from strain PCM 1531 and should be reclassified into another serogroup. [ABSTRACT FROM AUTHOR]

Strains of Pseudomonas syringae pv. porri are characterized by a number of pathovar-specific phenotypic and genomic characters and constitute a highly homogeneous group. Using monoclonal antibodies, they all were classified in a novel P. syringae serogroup O9. The O polysaccharides (OPS) isolated from the lipopolysaccharides (LPS) of P. syringae pv. porri NCPPB 3365 and NCPPB 3364T possess multiple oligosaccharide O repeats, some of which are linear and composed of l-rhamnose (l-Rha), whereas the major O repeats are branched with l-rhamnose in the main chain and GlcNAc in side chains (structures 1 and 2 ). Both branched O repeats, which differ in the position of substitution of one of the Rha residues and in the site of attachment of GlcNAc, were found in the two strains studied, O repeat 1 being major in strain NCPPB 3365 and 2 in strain NCPPB 3364T . &figfu1; The relationship between OPS chemotype and serotype on one hand and the genomic characters of P. syringae pv. porri and other pathovars delineated in genomospecies 4 on the other hand is fdiscussed. [ABSTRACT FROM AUTHOR]

The structure of the lipopolysaccharide (LPS) of Pseudomonas aeruginosa immunotype 1 was studied after mild acid and strong alkaline degradations by MS and NMR spectroscopy. Three types of LPS molecules were found, including those with an unsubstituted glycoform 1 core (A) or an isomeric glycoform 2 core substituted with one O-polysaccharide repeating unit (B) or with a long-chain O-polysaccharide. Therefore, of two core glycoforms, only glycoform 2 accepts the O-polysaccharide. &figfu1; In the structures A and B, Kdo, Hep, Hep7Cm, GalNAcAN3Ac, GalNFoAN, QuiNAc, GalNAla represent 3-deoxy-d-manno -octulosonic acid, l-glycero -d-manno -heptose, 7-O- carbamoyl-l-glycero -d-manno -heptose, 2-acetamido-3-O -acetyl-2-deoxygalacturonamide, 2-formamido-2-deoxygalacturonamide, 2-acetamido-2,6-dideoxyglucose and 2-(l-alanylamino)-2-deoxygalactose, respectively; all sugars are in the pyranose form and have the d configuration unless otherwise stated. One or more phosphorylation sites may be occupied by diphosphate groups. In a minority of the LPS molecules, an O-acetyl group is present in the outer core region at unknown position. The site and the configuration of the linkage between the O-polysaccharide and the core and the structure of the O-polysaccharide repeating unit were defined in P. aeruginosa immunotype 1. The QuiNAc residue linked to the Rha residue of the core was found to have the β configuration, whereas in the interior repeating units of the O-polysaccharide this residue is in the α-configuration. The data obtained are in accordance with the initiation of biosynthesis of the O-polysaccharide of P. aeruginosa O6, which is closely related to immunotype 1, by transfer of d-QuiNAc-1-P to undecaprenyl phosphate followed by synthesis of the repeating O-antigen tetrasaccharide. [ABSTRACT FROM AUTHOR]

The O-chain polysaccharide of the lipopolysaccharide (LPS) of a previously nonclassified strain of Proteus mirabilis termed G1 was studied by sugar analysis and 1 H and 13 C NMR spectroscopy, including 2D COSY, TOCSY, rotating-frame NOE (ROESY), H-detected 1 H,13 C HMQC, and heteronuclear multiple-bond correlation (HMBC) experiments. The following structure of the polysaccharide was established: &figfu1; where d-GalA6(l-Lys) stands for N α -(d-galacturonoyl)-l-lysine. The structure of the O-polysaccharide of P. mirabilis G1 is similar, but not identical, to that of P. mirabilis S1959 and OXK belonging to serogroup O3. Immunochemical studies with P. mirabilis G1 and S1959 anti-(O-polysaccharide) sera revealed close LPS-based serological relatedness of P. mirabilis G1 and S1959, and therefore it was suggested to classify P. mirabilis G1 in serogroup O3 as a subgroup. P. mirabilis G1 and S1959 anti-(O-polysaccharide) sera also cross-reacted with LPS of␣P. mirabilis strains from two other serogroups containing␣d-GalA6(l-Lys) in the O-polysaccharide or in the core region. [ABSTRACT FROM AUTHOR]

Previously, a phase-variable epitope was detected in the virulent wild-type strain RC1 of Legionella pneumophila serogroup 1 subgroup OLDA using a lipopolysaccharide-specific monoclonal antibody, mAb 2625 [Lüneberg, E., Zähringer, U., Knirel, Y. A., Steinmann, D., Hartmann, M., Steinmetz, I., Rohde, M., Kohl, J. & Frosch, M. (1998) J.␣Exp. Med. 188 , 49–60]. In the present study, an isogenic mutant strain, termed 5215, was constructed by deletion of genes involved in the biosynthesis of the mAb 2625 epitope. Mutant 5215 was as virulent as the parental wild-type RC1 but did not bind mAb 2625. The two strains showed no difference in the core oligosaccharide and lipid A but in the␣O-chain polysaccharide structure, which is a homopolymer of 5-acetimidoylamino-7-acetamido-3,5,7,9-tetradeoxy-d-glycero -d-galacto -non-2-ulosonic acid (a derivative of legionaminic acid). NMR spectroscopic studies revealed a hitherto unknown modification of bacterial polysaccharides in the wild-type strain, namely N -methylation of the 5-acetimidoylamino group on a single legionaminic acid residue that is located, most likely, proximal to the core oligosaccharide. Two major N-methylated substituents, the (N ,N -dimethylacetimidoyl)amino and acetimidoyl(N -methyl) amino groups, could be allocated to the long- and middle-chain O-polysaccharide species, respectively. N-Methylation of legionaminic acid that was absent from the isogenic mutant 5215 and from the spontaneous phase variant 811, correlated with the presence of the mAb 2625 epitope. [ABSTRACT FROM AUTHOR]

Mild acid degradation of the lipopolysaccharide of Citro- bacter gillenii O9a,9b released a polysaccharide (PS), which was found to consist of a single monosaccharide, 4-acetamido-4,6-dideoxy-d-mannose (d-Rha4NAc, N -acetyl-d-perosamine). PS was studied by methylation analysis␣and 1 H-NMR and 13 C-NMR spectroscopy, using two-dimensional 1 H,1 H COSY, TOCSY, NOESY, and H-detected 1 H,13 C heteronuclear correlation experiments. It was␣found that PS includes two structurally different polysaccharides: an α1→2-linked homopolymer of N -acetyl-d-perosamine [→2)-α-d-Rhap 4NAc-(1→, PS2] and a␣polysaccharide composed of tetrasaccharide repeating units (PS1) with the␣following structure: →3)-α-d-Rhap 4NAc-(1→2)-α-d-Rhap 4NAc-(1→2)-α-d-Rhap 4NAc-(1→3)-α-d-Rhap 4N Ac2Ac-(1→ where the degree of O-acetylation of a 3-substituted Rha4NAc residue at position 2 is ≈ 70%. PS could be fractionated into PS1 and PS2 by gel-permeation chromatography on TSK HW-50S. Matrix-assisted laser desorption ionization MS data indicate sequential chain elongation of both PS1 and PS2 by a single sugar unit, with O-acetylation in PS1 beginning at a certain chain length. Anti-(C. gillenii O9a,9b) serum reacted with PS1 in double immunodiffusion and immunoblotting, whereas neither PS2 nor the lipopolysaccharide of Vibrio cholerae O1 with a structurally related O-chain polysaccharide were reactive. [ABSTRACT FROM AUTHOR]

O-specific polysaccharides (O-antigens) of the lipopolysaccharides (LPS) of Proteus penneri strains 1 and 4 were studied using sugar analysis, ¹H and [sup 13]CNMR spectroscopy, including 2D COSY, H-detected ¹H,[sup 13]C HMQC, and rotating-frame NOE spectroscopy (ROESY). The following structures of the tetrasaccharide (strain 1) and pentasaccharide (strain 4) repeating units of the polysaccharides were established: →6)-β-D-Glcp-(1→3)-β-D-GalpNAc-(1β4)-α-D-G alp-(1→3 ↑ 1 β-D-GalpNAc →6)-β-D-Glcp-(1→3)-β-D-GalpNAc-(1→4)-α-D-G alp-(1→ 6 3 ↑ ↑ 1 1 α-D-Glcp β-D-GalpNAc 6 OAc In the polysaccharide of P. penneri strain 4, glycosylation with the lateral Glc residue (75%) and O-acetylation of the lateral GalNAc residue (55%) are nonstoichiometric. This polysaccharide contains also other, minor O-acetyl groups, whose positions were not determined. The structural similarity of the O-specific polysaccharides was consistent with the close serological relatedness of the LPS, which was demonstrated by immunochemical studies with O-antisera against P. penneri 1 and 4. Based on these data, it was proposed to classify P. penneri strains 1 and 4 into a new Proteus serogroup, O72, as two subgroups, O72a and O72a,b, respectively. Serological crossreactivity of P. penneri 1 O-antiserum with the LPS of P. penneri 40 and 41 was substantiated by the presence of an epitope(s) on the LPS core region shared by all P. penneri strains studied. [ABSTRACT FROM AUTHOR]

Lipopolysaccharide (LPS) expressed by isolates of Pseudomonas aeruginosa from cystic fibrosis patients lacks the O-polysaccharide chain but the degree to which the rest of the molecule changes has not been determined. We analyzed, for the first time, the core structure of an LPS from a rough, cystic fibrosis isolate of P. aeruginosa. The products of mild acid hydrolysis and strong alkaline degradation of the LPS were studied by ESI MS, MALDI MS, and NMR spectroscopy. The following structure was determined for the highest-phosphorylated core-lipid A backbone oligosaccharide isolated after alkaline deacylation of the LPS: &figf7; where Kdo and Hep are 3-deoxy-d-manno-octulosonic acid and l-glycero-d-manno-heptose, respectively; all sugars are in the pyranose form and have the d configuration unless stated otherwise. The outer core region occurs as two isomeric glycoforms differing in the position of rhamnose (Rha). The inner core region carries four phosphorylation sites at two Hep residues, HepI being predominantly bisphosphorylated and HepII monophosphorylated. In the intact LPS, both Hep residues carry monophosphate and diphosphate groups in nonstoichiometric quantities, GalN is N-acylated by an l-alanyl group, HepII is 7-O-carbamoylated, and the outer core region is nonstoichiometrically O-acetylated at four sites. Therefore, the switch to the LPS-rough phenotype in cystic fibrosis isolates of P. aeruginosa is not accompanied by losses of core monosaccharide, phosphate or acyl components. The exact positions of the O-acetyl groups and the role of the previously undescribed O-acetylation in the LPS core of P. aeruginosa remain to be determined. [ABSTRACT FROM AUTHOR]

The acidic O-specific polysaccharide chain (O-antigen) of the lipopolysaccharide (LPS) of Proteus mirabilis strain D52 was studied using chemical analyses along with 1H-NMR and 13C-NMR spectroscopy, including 2D COSY, TOCSY, ROESY, H-detected 1H,13C and 1H,31P HMQC experiments. The polysaccharide was found to contain d-ribitol 5-phosphate (d-Rib-ol-5-P) and ethanolamine phosphate (Etn-P) and has the following structure &figf4; This structure is identical with that of the O-polysaccharide of P. mirabilis O33 strain 59/57, and, hence, P. mirabilis D52 belongs to the same Proteus serogroup O33. Serological studies with O-antiserum against P. mirabilis D52 confirmed this but showed that the LPS species of P. mirabilis 59/57 and D52 are not identical, having different epitopes in the core region. A serological cross-reactivity of P. mirabilis D52 O-antiserum was observed with LPS of two other Proteus strains, P. mirabilis O16 and P. penneri 103, which have structurally different O-polysaccharides. The role of charged groups, Rib-ol-5-P and Etn-P in the immunospecificity is discussed. [ABSTRACT FROM AUTHOR]

Determines the structure of O-specific polysaccharides of Proteus vulgaris 021 and Proteus mirabilis 048 with oligosaccharide-phosphate repeating units. Derivation of polysaccharides and oligosaccharides from lipopolysaccharides; Examination on the virulence factors of Proteus; Analysis on the serological specificity of Proteus.

Cytochrome b558/566 from the archaeon Sulfolobus acidocaldarius (DSM 639) has been described as a novel highly glycosylated membrane-bound b-type hemoprotein [Hettmann, T., Schmidt, C. L., Anemüller, S., Zähringer, U., Moll, H., Petersen, A. & Schäfer, G. (1998) J. Biol. Chem. 273, 12032–12040]. The purified cytochrome b558/566 was characterized by MALDI MS as a 64-kDa (glyco)protein expressing 17% glycosylation. Detailed chemical studies showed that it was exclusively O-mannosylated with monosaccharides and N-glycosylated with at least seven hexasaccharide units having the same unique structure. The hexasaccharide was released by cleavage with peptide:N-glycosidase (PNGase) F and found to consist of two residues each of Man and GlcNAc and one residue each of Glc and 6-deoxy-6-sulfoglucose (6-sulfoquinovose). The last sugar has been known as a component of glycolipids of plants and some prokaryotes, but has not been hitherto found in bacterial glycoproteins. Digestion with trypsin/pronase gave a mixture of glycopeptides with the same Asn-linked hexasaccharide chain, from which an N-glycosylated Tyr-Asn dipeptide was purified by gel chromatography and anion-exchange HPLC. Studies of the degradation products using methylation analysis, ESI MS, MALDI MS, and 1H and 13C NMR spectroscopy, including 1H,13C HMQC and NOESY experiments, established the structure of the unique Asn-linked hexasaccharide chain of cytochrome b558/566. [ABSTRACT FROM AUTHOR]

Examines the structure of the O polysaccharide and serological classification of Pseudomonas syringae pv. ribicola NCPPB 1010. Existence of branched pentasaccharide repeating units of two types, major and minor; Differences in the position of substitution of one of the rhamnose residues; Formation of structurally homogeneous blocks within the same polysaccharide molecule.

Reports on the elucidation of complete structure of glycosphingolipids (GSL) isolated from gram-negative bacteria Sphingomonas capsulata lipopolysaccharide. Methanolysis and sugar analysis of GSL-3; Chemical shifts of GSL-3; Negative ion mode laser desorption mass spectra of GSL-3.

Studies the structure of a 2-aminoethyl phosphate-containing O-specific polysaccharide of Proteus penneri 8 from the serogroup O67. Process used for obtaining bacterial strains for the experiment; Method used for the preparation of O-antiserum and serological assays; Structure of the polysaccharide observed by chemical and nuclear magnetic resonance spectroscopic studies.

Analyzes the structure of the O-specific polysaccharide of Proteus penneri and classification of cross-reactive strains to a proposed serogroup O64. Description of the methods used for the isolation of lipopolysaccharides; Procedure used for the preparation of polyclonal O-antisera; Methylation analysis of the polysaccharide; Structure of the polysaccharide observed by nuclear magnetic resonance spectroscopy.

Analyzes the structure of a glycerol teichoic acid-like o-specific polysaccharide of Proteus vulgaris O12. Highlights of the methods of o-deacetylation and dephosphorylation; Sugar analysis and determination of the absolute configuration; Brief description of the chemical and nuclear magnetic resonance spectroscopic studies of the o-specific polysaccharide.

Studies the structure of a 2-aminoethyl phosphate-containing O-specific polysaccharide of Proteus penneri 63 from a serogroup O68. Isolation and degredation of lipopolysaccharides; Structural similarity of the O-specific polysaccharides of strains of Proteus penneri; Theoretical significance of the study.

Investigates the structure on lipopolysaccharides of serologically non-typable strains of Helicobacter pylori. Liberation of the carbohydrate portions; Development of gastric cancer; Relevance of Lewis antigen.

The O polysaccharide (OPS) of the lipopolysaccharide of Pseudomonas syringae pv. coriandricola GSPB 2028 (NCPPB 3780, W-43) was studied by Smith degradation and 1H-NMR and 13C-NMR spectroscopy, including two-dimensional COSY, TOCSY, NOESY, and H-detected 1H,13C heteronuclear multiple-quantum coherence (HMQC) experiments. The OPS was shown to consist of pentasaccharide O repeats of two types both containing four L-rhamnose and one 3-acetamido-3,6-dideoxy-D-galactose (D-Fuc3NAc) residue. Structure 1 of the major O repeat which had been established earlier [Das, S., Ramm, M., Kochanowski, H. & Basu, S. (1994) J. Bacteriol. 176, 6550-6557], was confirmed by our data, and a new structure 2 was elucidated for the minor O repeat and found to differ from the structure 1 only in the position of substitution of one of the rhamnose residues in the main chain. α-D-Fucp3NAc 1 ↓ 2 ←2)-α-L-Rhap-(1←2)-α-L-Rhap-(1←3)-α-L-Rhap-(1←3)-α-L-Rhap-(1← 1 α-D-Fucp3NAc 1 ↓ 2 ←3)-α-L-Rhap-(1←2)-α-L-Rhap-(1←3)-α-L-Rhap-(1←3)-α-L-Rhap-(1← 2 A role of structural and immunochemical features of the LPS for defining the taxonomical position of the bacterium studied is discussed. [ABSTRACT FROM AUTHOR]

O polysaccharides (OPS) of the lipopolysaccharides (LPS) of Pseudomonas syringae pathovar tomato GSPB 483 and pathovar maculicola IMV 381 were studied by 1H-NMR and 13C-NMR spectroscopy, including two-dimensional COSY, rotating-frame NOE spectroscopy (ROESY), and H-detected 1H,13C heteronuclear multiple-quantum coherence (HMQC) experiments. The OPS from both strains were shown to be chemically identical. Two structurally different types of repeating units (O repeats 1 and 2) were elucidated in each OPS. The minor O repeat is a pentasaccharide having the structure 2. The same structure has been reported earlier for some other OPS of P. syringae. The major O repeat is a hexasaccharide with the novel structure 1 which is distinguished from 2 by the presence of the second lateral residue of 3-acetamido-3,6-dideoxy-D-galactose (D-Fuc3NAc) and by a different position of substitution of one of the L-rhamnose (Rha) residues in the backbone. α-D-Fucp3NAc α-D-Fucp3NAc 1 1 ↓ ↓ 3 3 ←2)-α-L-Rhap-(1←2)-α-L-Rhap-(1←3)-α-L-Rhap-(1←3)-α-L-Rhap-(1← 1 α-D-Fucp3NAc 1 ↓ 3 ←2)-α-L-Rhap-(1←3)-α-L-Rhap-(1←3)-α-L-Rhap-(1←3)-α-L-Rhap-(1← 2 Structural and serological diversity of OPS of strains belonging to P. syringae pv. tomato and pv. maculicola and phylogenetic relatedness of the strains are discussed. [ABSTRACT FROM AUTHOR]

Examines the diversity in the O-antigen composition and structure of a serologically separate strain Proteus penneri 2. Composition of O-specific polysaccharide; Analysis of polysaccharide through methylation; Test of polyclonal rabbit anti-O-serum.

Examines the structure of the O-antigen of Proteus mirabilis O14. Characterization and composition of the O-specific polysaccharide; Elucidation of the structure of O-specific polysaccharide; Degradation of lipopolysaccharide.

The following structure of the O‐specific polysaccharide (OPS) of Proteus vulgaris O45 lipopolysaccharide (LPS) was established using 1H‐ and 13C‐NMR spectroscopy, including two‐dimensional NOESY and H‐detected 1H, 13C heteronuclear multiple‐quantum coherence (HMQC) experiments: &figfu1; Immunochemical studies, using rabbit polyclonal anti‐P. vulgaris O45 serum and LPS, OPS and Smith‐degraded OPS of P. vulgaris O45, showed the importance of β‐d‐GlcA in manifesting the serological specificity of the O‐antigen studied. [ABSTRACT FROM AUTHOR]

The following structure of the O-specific polysaccharide chain (O-antigen) of the Proteus vulgaris O32 lipopolysaccharide (LPS) was established by 1H-NMR and 13C-NMR spectroscopy, including two-dimensional NOESY and H-detected 1H,13C heteronuclear multiple-quantum coherence (HMQC) experiments : ←2)-α-L-RhapI-(1←2)-α-L-RhapII-(1←4)-β-D-GalpAI-(1←3)-β-D-GlcpNAc-(1←4)-α-D-GalpAII-(1←. In addition, an O-acetyl group was detected, which, most probably, is located at position 3 of a part of RhapI residues. Serological studies, using rabbit polyclonal anti-(P. vulgaris O32) serum, homologous and heterologous Proteus O-antigens and related artificial antigens, revealed the importance of an α-D-GalA-associated epitope in manifesting the immunospecificity of P. vulgaris O32 and substantiated serological relationships between the O-antigen studied and those of some other Proteus strains. [ABSTRACT FROM AUTHOR]

An R-type lipopolysaccharide (LPS) from Erwinia carotovora strain FERM P-7576 was studied after strong alkaline degradation and mild acid hydrolysis. The resulting products were analyzed by fast-atom bombardment mass spectrometry, one- and two-dimensional 1H and 13C NMR spectroscopy, dephosphorylation and methylation analysis. The following structure was proposed for the core region of the LPS: [This symbol cannot be presented in ASCII format] where Hep is L-glycero-D-manno-heptose and Kdo is 3-deoxy-D-manno-octulosonic acid. Some LPS species lack the β-D GAlp residue or the β-D-Galp-(1→7)-α-Hepp disaccharide. With the known structures of lipid A [Fukuoka, S., Kamishima, H., Nagawa. Y., Nakanishi, H., Ishikawa, K., Niwa, Y., Tamiya, E. & Karube, I. (1992) Arch. Microbiol. 157, 311–318] and the core moiety, the complete LPS structure was established and confirmed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry of the native and O-deacylated LPS. [ABSTRACT FROM AUTHOR]

Reports on a Vibrio cholerae O139 strain, MO10-T4, lacking capsular polysaccharide, which produces a short-chain lipopolysaccharide (LPS) similar to enterobacterial SR strains. Study of the strain by acidic and alkaline degradation, dephosphorylation, sugar and methylation analysis; Structure proposed for the core region of the LPS; Presence of an O-acetyl group on a secondary position; Additional putative fructose residue contained by some LPS species.

The O-specific polysaccharide of an Aeromonas trota strain was isolated by hydrolysis of the lipopolysaccharide at pH 4.5 followed by gel-permeation chromatography and found to consist of hexasaccharide repeating units containing D-galactose, L-rhamnose, 3,6-dideoxy-L-xylo-hexose (colitose, Col), 2-acetamido-2-deoxy-D-glucose and 2-acetamido-2-deoxy-D-galactose in the ratios 1:1:2:1:1. Partial hydrolysis of the polysaccharide with 48% hydrofluoric acid resulted in selective removal of colitose to give a modified polysaccharide containing the other four sugar constituents. On the basis of methylation analysis and NMR spectroscopic studies of the initial and modified, colitose-free polysaccharide, it was concluded that the repeating unit of the O-specific polysaccharide has the following structure [This text cannot be captured in ASCII.text] The known cross-reactivity between the strain studied and Vibrio cholerae O139 Bengal is substantiated by the presence of a common colitose-containing epitope shared by the O-specific polysaccharide of A. trota and the capsular polysaccharide of V. cholerae, which is thought to carry determinants of O-specificity. [ABSTRACT FROM AUTHOR]

On the basis of sugar analysis and NMR spectroscopy, including selective spin-decoupling, one-dimensional NOE, two-dimensional homonuclear and 13C,¹H-heteronuclear correlation spectroscopy, the following structure of the acidic O-specific polysaccharide of Proteus mirabilis O43 was established: →4)-α-D-GalpA-(1→3)-α-D-GalpA-(1→3)-α-D-Gl cpNAc-(1→4)-α - D-Glcp-(1→, where GalA is galacturonic acid and Galp is galactopyranose. No serological cross-reactivity was observed between lipopolysaccharides of P. mirabilis O43 and other studied Proteus strains, except for P. mirabilis O10. The O-specific polysaccharide of P. mirabilis O43 was serologically active in precipitation and inhibition tests but the activity was lost after periodate oxidation. These data suggest that the O43 specificity is determined by a wide epitope with the immunodominant role of 4-substituted D-Glc or/and D-GalA, which are destroyed by periodate oxidation. [ABSTRACT FROM AUTHOR]

The capsular polysaccharide (CPS) of Vibrio cholerae O139 synonym Bengal, which is thought to carry determinants of O-specificity, was isolated by phenol/water extraction followed by delipidation of the contaminating lipopolysaccharide at pH 4.2 and gel-permeation chromatography. The CPS contained D-galactose, 3,6-dideoxy-L-xylo-hexose (colitose, Col), 2-acetamido-2-deoxy-D-glucose, 2-acetamido-2,6-dideoxy-D-glucose (N-acetyl-D-quinovosamine, D-QuiNAc), D-galacturonic acid (D-GalA), and phosphate. The CPS was studied by NMR spectroscopy, methylation analysis, and selective degradations, including partial acid hydrolysis at pH 3.1 and dephosphorylation with aqueous 48% hydrofluoric acid, which both resulted in complete cleavage of Col. It was concluded that the CPS is built up of hexasaccharide repeating units containing inter alia D-galactose 4,6-cyclophosphate and having the following structure [This structure can not be represented in to (ASCII.txt)] These data basically confirm the structure of the V. cholerae CPS proposed on the basis of an NMR study [L. M. Preston et al. (1995) J. Bacteriol. 177, 835-838] and specify exactly the absolute configurations of the constituent monosaccharides and the position of the cyclic phosphate. [ABSTRACT FROM AUTHOR]

Structural and immunochemical studies have been performed on the O-specific antigens of two serologically related types of Pseudomonas aeruginosa O:2a,b and O:2a,c (Lanyi's classification). The O-specific polysaccharide chains of the two serotypes were shown to be acidic polysaccharides composed of repeating trisaccharide units consisting of L-rhamnose, N-acetyl-D-quinovosamine and N-acetyl-L-galactosaminuronic acid residues. Based on 1H and 13C nuclear magnetic resonance spectroscopy, data of methylation analysis and selective solvolysis with hydrogen fluoride, the repeating unit of the O:2a,c O-specific polysaccharide was assigned the following structure: →4)LGalNAcA(α1 → 3)DQuiNAc(α1 » 3)LRha(α1, where GalNAcA = N-acetylgalactosaminuronic acid, QuiNAc = N-acetylquinovosamine and Rha = rhamnose. The O:2a,b O-specific polysaccharide had the same structure of the trisaccharide repeating unit but was distinguished by the presence of O-acetyl groups on 70–80% of the rhamnose residues in position 2. The O-acetyl groups were located both by methylation with methyltrifluoromethane sulphonate and by comparison of the 13C nuclear magnetic resonance spectra of the native and O-deacetylated polysaccharides. Serological studies revealed the determinant role of the O-acetyl groups in the O-antigen O:2a,b and suggested the O-factor 2b to be related to the 2-O-acetyl-L-rhamnose residue, whereas the O-factor 2c was probably determined by the nonacetylated rhamnose residue. The dominant moiety of the determinant 2a common to the two antigens was obviously presented by the N-acetyl-L-galactosaminuronic acid residue. [ABSTRACT FROM AUTHOR]

A loosely bound lipopolysaccharide-protein complex was extracted from cells of Pseudomonas aeruginosa strain 170015 (O:7ab; Lanyi classification) by saline solution and purified from contaminant nucleic acid by Cetavlon treatment followed by precipitation in an ultracentrifuge. The saline-treated cells were re-extracted with hot aqueous phenol to give firmly bound lipopolysaccharide which was isolated from the phenol layer and purified by ultracentrifugation. The identity of both lipopolysaccharide preparations was proved by serological and chemical evidence. Mild acid degradation of the lipopolysaccharide resulted the splitting off of a lipid component and led to polysaccharide which was purified by gel-filtration on a Sephadex G-50 column. The polysaccharide consisted of N-acetyl-D-fucosamine, N-acetyl-L-fucosamine and D-glucose in the ratio 1:1:1. On the basis of nuclear magnetic resonance spectra, results of methylation analysis and two sequential Smith degradations, the following structure can be assigned to the repeating unit of the polysaccharide: -3)LFucNAc(αl-3)DFucNAc(β1-2)DGlc(β1-. The polysaccharide did not show serological activity whereas alkali-treated lipopolysaccharide readily sensitised sheep erythrocytes and inhibited the passive haemagglutination reaction with anti-(O:7a,b)serum. Evidence is presented that the oligosaccharide repeating units of the polysaccharide and alkali-treated lipopolysaccharide are indistinguishable. Ps. aeruginosa strain 170016 (O:7a,c) was shown to have the O-specific lipopolysaccharide identical with that from strain 170015. The presented data show that subfactors 7b,and 7c in the Lanyi classification of Ps. aeruginosa O-antigens seem to relate to components of the bacterial surface other than lipopolysaccharides. [ABSTRACT FROM AUTHOR]

Two lipopolysaccharide preparations were obtained from Escherichia coli 058 by extraction with 45% aqueous phenol and fractional precipitation with cetyltrimethyl ammonium bromide (Cetavlon). Chemical analysis and polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate showed that the two preparations differed only in the extent of the O-specific polysaccharide moiety. The O-specific polysaccharide was characterized with proton magnetic resonance and infrared spectroscopy, optical rotation and paper electrophoresis. Using gas-liquid chromatography and ion-exchange chromatography, it was shown to contain D-mannose, 2-acetamido-2-deoxy-D-glucose, 3-O-(R-1'-carboxyethyl)-L-rhamnose (rhamnolactylic acid), and O-acetyl groups in the molar ratios of 2:1:1:1. The polysaccharide and oligosaccharides obtained from it were subjected to methylation and chromic acid oxidation. The results obtained indicated that the polysaccharide consists of tetrasaccharide repeating units in which the trisaccharide β-GlcNAc1-4αMan-1-4(2/3-O-Ac)-Man is substituted at C-3 of the non-acetylated mannose with rhamnolactylic acid. The repeating units are joined through α-mannosyl-1-3-glucosamine bonds. This structure is identical with that of the cell wall polysaccharide of Shigella dysenteriae type 5. [ABSTRACT FROM AUTHOR]

The O-specific polysaccharide obtained from Shigella dysenteriae type-2 lipopolysaccharide by mild acid hydrolysis consisted of N-acetylgalactosamine, N-acetylglucosamine, D-galactose, D-glucose, and O-acetyl group in the ratio of 2:1:1:1:1. A number of oligosaccharides were obtained by deamination of the N-deacetylated polysaccharide and by Smith degradation of the both native and O-deacetylated polysaccharides. The identification of oligosaccharides along with methylation analysis and chromic anhydride oxidation showed that the polysaccharide was built up of the repeating pentasaccharide units whose proposed structure is given below: -3αD-GalNAcp1-3αD-GalNAcp1-4αD-Glcp1-4βD-Galp1-3(4)AcαD-GlcNAcp1 [This symbol cannot be presented in ASCII format] Serological properties of Sh. dysenteriae O-specific polysaccharides are discussed. [ABSTRACT FROM AUTHOR]

The O-specific polysaccharide obtained from the lipopolysaccharide of Shigella dysenteriae type 1 (Shigella shiga) by mild acid hydrolysis followed by fractionation on Sephadex G-50 was found to be identical to that described by Morgan's group and was composed of L-rhamnose, D-galactose and N-acetyl-D-glucosamine in a ratio 2:1:1. On the basis of methylation analysis data the polysaccharide was proved to be a linear chain of monosaccharide residues in pyranose forms substituted at position 3, except for that of galactose substituted at position 2. Selective cleavage, based on the N-deacetylation reaction of the polymer, together with determination of linkage configurations by chromic anhydride oxidation showed that the O-specific polysaccharide is built up of repeating tetrasaccharide units whose proposed structure is given below [This symbol cannot be presented in ASCII format] where Rhap = rhamnopyranose, Galp = galactopyranose, and GlcNAcp = N-acetyl-glucosamine. The present findings confirmed the considerations of Heidelberger on the substitution patterns of n-rhamnose and D-galactose residues from the results of serological studies. [ABSTRACT FROM AUTHOR]

O-specific polysaccharides, obtained on mild acid degradation of lipopolysacchrides of the serologically related strains Pseudomonas aeruginosa O3 (L´nyi classification), O25 (Wokatsch classification) and immunotypes 3 and 7 (Fisher classification), are built up of trisaccharide repeating units involving 2-acetamido-2,6-dideoxy-D-galactose (N-acetyl-D-fucosamine), 2,3-diacetarnido-2,3-dideoxy-D-mannuronic acid or 2,3-diacetamido-2,3-dideoxy-L-guluronic acid and 3-acetamidino-2-acetamido-2,3-dideoxy-D-mannuronic acid or 3-acetamidino-2-acetamido-2,3-dideoxy-L-guluronic acid. Lányi O3(a),3d,3f and Wokatsch O25 polysaccharides contain also O-acetyl groups. On the basis of solvolysis with anhydrous hydrogen fluoride, resulting in trisaccharide fragments with N-acetylfucosamine residue at the reducing terminus, chemical modifications of the acetamidino group (alkaline hydrolysis to the acetamido group or reductive deamination to the ethylarnino group), as well as analysis by ¹H-NMR (including nuclear Overhauser effect experiments) and 13C-NMR spectroscopy, and fast-atom bombardment mass spectrometry, it was concluded that the repeating units of the polysaccharides have the following structures: [This equation cannot be converted into ASCII text.] where HexNAcAmA = α-L-GulNAcAmA (&approx;70%) or β-D-ManNAcAmA (&approx;30%). Lányi O3(a),3d,3f polysaccharide involves two types of repeating units, which differ from each other only in the configuration at C-5 of the 3-acetamidino-2-acetamido-2,3-dideoxyuronic acid residue. Lányi O3(a),3c, O3a,3d,3e and Fisher immunotypes 3 and 7 polysaccharides contain, together with the major repeating units shown above, a small proportion of units in which the derivative of &aalpha;-L-guluronic acid is replaced by the corresponding β-D-manno isomer. The data obtained provide the opportunity to substantiate the serological interrelations between these strains of P. aeruginosa by the presence in the O-specific polysaccharides of common monosaccharides or disaccharide fragments. The distinctions between them stem from the presence or absence of the O-acetyl group, a different configuration of the glycosidic linkage of the N-acetylfucosamine residue and/or a different configuration at C-5 of one or both derivatives of diaminouronic acids. [ABSTRACT FROM AUTHOR]

Mild acid degradation of lipopolysaccharides from Pseudomonas aeruginosa O10a and O10a,b (Lányi classification) resulted in O-specific polysaccharides built up of trisaccharide repeating units containing 2-acetamido-2,6-dideoxy-D-glucose (N-acetylquinovosamine, DQuiNAc), 2-acetamido-2,6-dideoxy-D-galactose (N-acetylfucosamine, DFucNAc), and 5-acetamido-3,5,7,9-tetradeoxy-7-[(R)-3-hydroxybutyramido]-L-glycero-L-mannononulosonic acid. The latter is a di-N-acyl derivative of a new sialic-acid-like sugar which was called by us pseudaminic acid (PseN2). A 3-hydroxybutyric acid residue was also found in natural carbohydrates for the first time. In the O10a,b polysaccharide pseudaminic acid carried an O-acetyl group at position 4. For selective cleavage of the O10a polysaccharide, solvolysis with hydrogen fluoride was employed which, owing to the relatively high stability of the glycosidic linkage of pseudaminic acid, led to the disaccharide with this sugar on the non-reducing terminus. Performing the solvolysis in methanol afforded the methyl glycoside of this disaccharide which proved to be more advantageous for further analysis. Carboxyl-reduction made the glycosidic linkage of pseudaminic acid extremely labile, and mild acid hydrolysis of the carboxyl-reduced O10a polysaccharide afforded the trisaccharide with a ketose derivative on the reducing terminus. Establishing the structure of the oligosaccharide fragments obtained and interpreting the 13C nuclear resonance spectra of the polysaccharides allowed to determine the following structure for their repeating units: → 4)DFucNAc(α1 → 3)DQuiNAc(β1 → OCHCH2CO → 7)PseN2Ac(β2 I 41 (R) CH3 OR serotype O10a R = H serotype O10a,b R = Ac In the polysaccharides the N-acetylquinovosamine residue is attached not to pseudaminic acid itself, but to its N-acyl substituent, 3-hydroxybutyryl group, and thus the monomers are linked via both glycosidic and amidic linkages. [ABSTRACT FROM AUTHOR]

Lipopolysaccharides from Pseudomonas aeruginosa Ol (Lányi classification), O3 (Habs classification), O13 and 014 (Wokatsch classification), and strain NCTC 8505, which is also related to serogroup O3 (Habs). have structurally similar O-specific polysaccharide chains built up of tetrasaccharide repeating units involving L-rhamnose (Rha), 2-acetamido-2-deoxy-D-glucose (GlcNAc), 2-acetamido-2-deoxy-L-galacturonic acid (GalNAcA), and a di-N-acyl derivative of bacillosamine (BacN): 2,4-diacetamido-2,4,6-trideoxy-D-glucose or 2-acetamido-2,4,6-trideoxy-4-[(5)-3-hydroxybutyramido]-D-glucose. The latter derivative was obtained free by solvolysis with hydrogen fluoride of carboxyl-reduced Habs O3 polysaccharide, and was identified by 'H-nuclear magnetic resonance spectroscopy and by mass spectrometry of the corresponding methylated alditol. Habs O3, Lanyi O1, and Wokatsch 014 polysaccharides contained O-acetyl groups. Solvolysis with hydrogen fluoride of the native Habs O3 polysaccharide resulted in selective cleavage of the glycosidic linkages of 6-deoxy sugars to give the trisaccharide fragment involving all three N-acylated amino sugars. Similar solvolysis of NCTC 8505 polysaccharide afforded a mixture of disaccharide and trisaccharide with N,N'-diacetylbacillosamine at the reducing end. Smith degradation of Habs O3 polysaccharide resulted in selective oxidation of rhamnose to give a glycoside of a trisaccharide with glyceraldehyde as the aglycone. Smith degradation of NCTC 8505 polysaccharide was complicated by the formation of the glycoside of a trisaccharide with an aglycone of unknown structure. A trisaccharide with rhamnose at the reducing end was also isolated after Smith degradation of the latter polysaccharide. Analysis of the composition and structure of all oligosaceharides obtained, and detailed examination of the 13C-nuclear magnetic resonance spectra of these oligosaceharides, and of both intact and modified polysaccharides, revealed the following structures of the repeating units. The structure for the NCTC 8505 polysaccharide differs from that proposed previously [Tahara, Y. and Wilkinson, S. G. (1983) Eur. J. Biochem. 134. 299 - 304] in the configurations assigned to the glycosidic linkages of rhamnose and bacillosamine. The results obtained show the P. aeruginosa strains studied to represent three different O-serotypes in a single O-serogroup. [ABSTRACT FROM AUTHOR]

Acidic O-specific polysaccharides were isolated on mild acidic degradation of lipopolysaccharides of Pseudomonas aeruginosa serotypes O4a,b, O4a,c, O4a,d (Lányi classification) and serologically related to them serotype O6 (Habs classification) and immunotype 1 (Fisher classification). The polysaccharides had identical monosaccharide composition and were built up of L-rhamnose, 2-acetamido-2,6-dideoxy-D-glucose. 2formamido-2-deoxy-D-galacturonic acid and 2-acetamido-2-deoxy-o-galactouronamide residues. The latter two derivatives of D-galactosaminuronic acid were found in nature for the first time. All the polysaccharides, but Lányi serotype O4a,c, contained O-acetyl groups. The polysaccharides were readily de-O-acetylated with aqueous triethylamine and de-N-formylated with dilute hydrochloric acid. De-N-formylated polysaccharide of serotype O4a.c was selectively cleaved with nitrous acid upon 2-amino-2-deoxygalacturonic acid residues to form a tetrasaccharide with a 2,5-anhydrotaluronic acid residue on the reducing end. The tetrasaccharide represented a modified repeating unit of the polysaccharide. Solvolysis of all intact polysaccharides with hydrogen fluoride selectively split the glycosidic linkages of 6-deoxy sugars to give the same trisaccharide, including both derivatives of galactosaminuronic acid and having 2-acetamido-2,6-dideoxyglucose on the reducing end. Structural investigation of the oligosaccharides obtained together with methylation analysis and 13C nuclear magnetic resonance data revealed the following structures of the O-specific polysaccharides: ... An independent confirmation of the structures of the repeating units was obtained as the result of full interpretation of the 13C nuclear magnetic resonance spectra of the intact and modified polymers. Spectral data analysis revealed a number of regularities in the effects of glycosidation connecting their values with the anomeric and absolute... [ABSTRACT FROM AUTHOR]