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Biomedical subjects

B Jann

Publications and source records attributed to B Jann.

At least 73 records · Page 4Linked to original sources
PubMed1986

Genetic and biochemical analysis of Shigella dysenteriae 1 O antigen polysaccharide biosynthesis in Escherichia coli K-12: 9 kb plasmid of S. dysenteriae 1 determines addition of a galactose residue to the lipopolysaccharide core.

Production of the somatic antigen, O-specific polysaccharide of Shigella dysenteriae 1 is determined by the chromosomal rfb gene cluster and the rfp gene located on the 9 kb plasmid pHW400 carried by this organism. When transferred to Escherichia coli K-12, which produces lipopolysaccharide consisting only of core oligosaccharide linked to lipid A, rfp gene-containing plasmids caused modification of the core oligosaccharide leading to the appearance of core molecules with new electrophoretic mobilities. Chemical analysis of the modified core has shown that it is substituted with a galactose residue which is the first sugar of the O-polysaccharide repeat unit.

Antigens, Bacterial↗
PubMed1986

Genetic and biochemical analysis of Shigella dysenteriae 1 O antigen polysaccharide biosynthesis in Escherichia coli K-12: structure and functions of the rfb gene cluster.

The genetic organization and functions of the Shigella dysenteriae 1 rfb gene cluster, which specifies the somatic O antigen in this organism, have been studied in Escherichia coli K-12 by insertion and deletion mutagenesis of pSS9, a pBR322 hybrid containing the Shigella rfb genes. On the basis of the sensitivity/resistance to rough-specific bacteriophage T3 of E. coli K-12 derivatives containing mutant pSS9 plasmids, of the banding patterns and immunoreactivity of LPS isolated from such derivatives and electrophoresed on SDS-polyacrylamide gels, and of the sugar composition of the polysaccharide portion of the LPS determined by chemical analysis, six determinants for O antigen production were identified and localized. At least two determinants are involved in synthesis of TDP-rhamnose and the transfer of a rhamnose residue to the galactose-substituted core. One of these functions is probably TDP-rhamnose synthetase. A third function effects the transfer of a second rhamnose residue to the rha----gal-substituted core. A fourth function, for which evidence was obtained for two determinants (cistrons), is N-acetylglucosamine transferase, whereas a sixth determinant is necessary for extension of the first completed side chain repeat unit to the full O antigen polymer. These results confirmed the previously-determined chemical composition of the S. dysenteriae 1 O antigen and demonstrated that the order of the sugars is glcNAc----rha----rha----gal with gal as the first sugar linked to the core. Evidence was obtained for at least two transcriptional units in the rfb gene cluster and the approximate locations of two promoters are suggested. The detection of new electrophoretic species of LPS that may correspond to LPS biosynthetic intermediates, and the finding on the cell surfaces of structures corresponding to LPS core substituted with one or more O-specific sugars, appear to be novel findings.

Antigens, Bacterial↗
PubMed1986

Monoclonal antibodies against the nonhemagglutinating fimbrial antigen 1C (pseudotype 1) of Escherichia coli.

Hybridoma-derived monoclonal antibodies were produced with fimbrial preparations from Escherichia coli 20025 (04:K12:H-) with fimbrial (F) antigens 1C, 13, one related to 12, and one preliminarily termed y and from E. coli 2980 (018ac:K5:H-) with F antigens 1C and 8. Two clones of subclonal hybrid cells were studied which produced monoclonal antibodies (mc-20025-F2b, immunoglobulin G2b [IgG2b]; mc-2980-F2, IgG1) that were reactive with E. coli 20025, 2980, and a number of additional strains which exhibited the F1C antigen. Results of enzyme-linked immunosorbent assay and Western blot analysis indicated that the antibodies had F1C specificity, and competitive enzyme-linked immunosorbent assay with 125I-labeled antibodies showed that they recognized different epitopes on the fimbrial subunit. Neither of the antibodies agglutinated F1C-fimbriated E. coli but bound to the bacteria. There was no binding to E. coli without F1C fimbriae.

Adhesiveness↗
PubMed1986

A reexamination of the O1 lipopolysaccharide antigen group of Escherichia coli.

A total of 64 Escherichia coli strains of the O1 serogroup were tested for the migration pattern of their lipopolysaccharides (LPS) on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. O1:K1 and O1:K51 strains of the OMP5 outer membrane protein pattern possessed LPS with a doublet pattern (O1A1) or the lowermost band of the O1A1 doublet (O1A2). O1:K1 strains of the OMP9 pattern possessed LPS referred to as O1A, which corresponded to the uppermost band of the O1A1 doublet pattern. A few O1:K? strains possessed LPS of different migration patterns (O1B and O1C). O1A and O1A1 LPS were indistinguishable by chemical techniques, and both reacted with each of 10 different monoclonal antibodies tested. However, O1A1 had an additional epitope within the additional band in each doublet, as demonstrated by adsorption experiments with hyperimmune rabbit sera followed by Western blotting. Furthermore, purified polysaccharide from O1A bacteria was incapable of inhibition in enzyme-linked immunosorbent assays performed with O1A1 LPS as antigen and adsorbed, specific anti-O1A1 antibodies, whereas O1A1 polysaccharide inhibited this reaction. O1B and O1C LPS differed in all respects tested, including chemical composition, from O1A and O1A1 LPS.

Animals↗
PubMed1985

Structure of the K95 antigen from Escherichia coli O75:K95:H5, a capsular polysaccharide containing furanosidic KDO-residues.

The structure of the K95 antigenic capsular polysaccharide (K95 antigen) of Escherichia coli O75:K95:H5 was elucidated by determination of the composition, 1H- and 13C-n.m.r. spectroscopy, periodate oxidation, and methylation analysis. The K95 polysaccharide, which contains furanosidic 3-deoxy-D-manno-2-octulosonic acid (KDOf) residues, consists of----3)-beta-D-Rib-(1----8)-KDOf-(2----repeating units, has a molecular weight of approximately 25,000 (approximately 65 repeating units), and is randomly O-acetylated (1 acetyl group per repeating unit at unknown positions).

Carbohydrate Conformation↗
PubMed1985

Structural studies of the capsular polysaccharide of Acinetobacter calcoaceticus BD4.

Compositional analysis of the intact and carboxyl-reduced capsular polysaccharide of Acinetobacter calcoaceticus BD4 (PS-4) showed it to consist of L-rhamnose, D-glucose, D-glucuronic and D-mannose in molar ratios of 4:1:1:1. 13C-nuclear magnetic resonance spectroscopy, methylation analysis, oligosaccharide analysis and base-catalyzed beta-elimination were used to elucidate the primary structure. Oligosaccharides were obtained by enzymatic depolymerization with a specific bacteriophage-induced depolymerase and by partial acid hydrolysis. Form the results it is concluded that PS-4 consists of repeating units of the heptasaccharide (Formula: see text). The bacteriophage-induced depolymerase was found to be an endo-beta-D-glucosidase that hydrolyzed the bond beta-D-Glc-(1----3)-L-Rha to generate a heptasaccharide in 40% yield.

Acinetobacter↗
PubMed1985

Crossreactions of Escherichia coli K and O polysaccharides in antipneumococcal and anti-Salmonella sera.

Crossreactions of 24 K polysaccharides and 4 O polysaccharides of E. coli in antisera to 27 pneumococcal types, 3 anti-Salmonella sera, and anti-Klebsiella Kl serum are discussed in relation to structural features of the polysaccharides insofar as these are known. Predictions based on the crossprecipitations are also ventured for several instances in which structures are as yet undetermined.

Animals↗
PubMed1985

Structure of the amino acid-containing capsular polysaccharide (K54 antigen) from Escherichia coli O6:K54:H10.

The structure of the K54-antigenic polysaccharide (K54 antigen) of Escherichia coli O6:K54:H10 was elucidated by determination of the composition, 1H- and 13C-n.m.r. spectroscopy, periodate oxidation, and a study of the oligosaccharides obtained by partial hydrolysis with acid. The K54 polysaccharide consists of----3)-beta-D-glucosyluronic acid-(1----3)-alpha-L-rhamnosyl-(1----repeating-units. Of the glucuronic acid residues, approximately 85% are substituted in the ratio 9:1 with L-threonine and L-serine amidically linked to the carboxyl group. The K54 polysaccharide has a molecular weight of approximately 160,000, corresponding to approximately 380 repeating-units.

Amino Acids↗
PubMed1985

Structure of the fructose-containing K52 capsular polysaccharide of uropathogenic Escherichia coli O4:K52:H-.

The chemical structure of the K52 antigenic capsular polysaccharide (K52 antigen) of Escherichia coli O4:K52:H- was elucidated by composition, nuclear magnetic resonance spectroscopy, methylation, periodate oxidation before and after graded acid hydrolysis and by oligosaccharide analysis. The polysaccharide consists of a backbone of alpha-galactose units interlinked between C1 and C3 by phosphodiester bridges. This poly(alpha-galactosyl-phosphate) is substituted at C2 of each galactose unit by beta-fructofuranose residues. About 80% of the galactose units are O-acetylated at C4 and about 10% of the fructose units are both O-acetylated and O-propionylated at C1. The K52 polysaccharide has an average molecular mass of 34 kDa, thus consisting of approximately 65 fructosyl-galactosyl-phosphate repeating units.

Antigens, Bacterial↗
PubMed1985

Monoclonal antibodies to enterobacterial common antigen and to Escherichia coli lipopolysaccharide outer core: demonstration of an antigenic determinant shared by enterobacterial common antigen and E. coli K5 capsular polysaccharide.

We established hybridoma cell lines producing monoclonal antibodies against enterobacterial common antigen (ECA) and a substructure of the outer core of different Escherichia coli lipopolysaccharides (LPSs). Anti-ECA antibodies 865 and 898 reacted with ECA in extracts of heated E. coli and with ECA-bound R1 and R4 core-containing LPS preparations, as well as with a purified sample of ECA from Salmonella montevideo. Antibody 865, but not antibody 898, cross-reacted with K5 capsular polysaccharide, suggesting that 4-linked alpha-N-acetylglucosamine is part of an antigenic determinant shared by both K5 polysaccharide and ECA. Anti-LPS antibody 786 recognized an outer core structure common to E. coli K-12, B, R2, and R4 core type LPS, but not to R1 and R3 core type LPS. Its most probable target is the trisaccharide sequence Hexp(1----2)-alpha-D -Glcp(1----3) alpha-D-Glcp----(Hepp) (where Hex is hexose, p is phosphate, Glc is glucose, and Hep is heptose), the first glucose being the immunodominant moiety. These monoclonal antibodies may be used not only for the detection of ECA, K5, and LPS core structures but also for analysis of the molecular forms resolved on polyacrylamide gels (banding patterns) of both ECA and LPS, independently of one another.

Antibodies, Monoclonal↗
PubMed1984

Biosynthesis of the 09 antigen of Escherichia coli. Core structure of rfe mutant as indication of assembly mechanism.

The chemical structure of the outer (hexose) regions of the core oligosaccharide from Escherichia coli 09 with the complete R1 core, and from a R1-derived rfe mutant were analyzed using compositional analysis, methylation and gas chromatography/mass spectrometry. It was found that, in contrast to the branched outer region of the R1 core, the outer region of the core from the rfe mutant lacked terminal glucose and was linear. These results are in agreement with recent findings on the biosynthesis of the 09 antigen. They suggest a cotransfer of glucose with the 09-specific mannan to a 'pre-core' lacking terminal glucose, as the assembly (translocation) step in the 09 antigen synthesis. Thus it is suggested that the initiation of O-chain synthesis (by the formation of an acceptor glucolipid ) and the termination of core synthesis are closely correlated. In conjunction with previous biochemical data, the analytical results presented here indicate a novel core synthesis.

Antigens, Bacterial↗
PubMed1984

Structural studies of the O-specific side chain of the lipopolysaccharide from Escherichia coli O:7.

The structure of the O-specific side-chain of the lipopolysaccharide from Escherichia coli O:7 has been investigated, using n.m.r. spectroscopy, methylation analysis, partial hydrolysis, and Smith degradation as the principal methods. It is concluded that the polysaccharide is constructed of repeating pentasaccharide units having the structure (formula; see text) where D-QuipNAc stands for 4-acetamido-4,6-dideoxy-D-glucopyranose. The 13C-n.m.r. spectrum of the polysaccharide has been interpreted completely.

Carbohydrate Conformation↗
PubMed1984

Escherichia coli O18ac antigen: structure of the O-specific polysaccharide moiety.

The O-specific polysaccharide moiety (O18ac polysaccharide) of the O18ac antigen (lipopolysaccharide) from Escherichia coli 2980 (O18ac:K5:Fim+:H-) was isolated in pure form by degradation of the lipopolysaccharide and chromatography on Sephadex G-50. The primary structure of the O18ac polysaccharide was elucidated by composition, fragmentation procedures, methylation analysis, and nuclear magnetic resonance spectroscopy. The polysaccharide consists of repeating units of the pentasaccharide: (formula; see text) which are joined in the polymer by alpha-1,2 linkages.

Antigens, Bacterial↗
PubMed1983

Cell-wall lipopolysaccharide of the urinary-tract-infective Escherichia coli 04:K12:H-. Structure of the polysaccharide chain.

The O-specific polysaccharide moiety (04 polysaccharide) of the 04 antigen (lipopolysaccharide) from Escherichia coli 04:K12:H- was isolated in pure form by degradation of the lipopolysaccharide and chromatography on Sephadex G-50. The primary structure of the 04 polysaccharide was elucidated by composition, Smith degradation, nuclear magnetic resonance spectroscopy, methylation and oligosaccharide analysis. Oligosaccharides were obtained by deaminating fragmentation of partially and completely de-N-acetylated polysaccharides. The polysaccharide consists of repeating units of the pentasaccharide (formula; see text) which are joined in the polymer through alpha-1, 4-linkages. The 04 polysaccharide has a mean molecular mass of 13800 Da and consists of the core oligosaccharide and about 14 pentasaccharide repeating units.

Carbohydrate Conformation↗
PubMed1983

Structure of the 3-deoxy-D-manno-octulosonic acid-(KDO)-containing capsular polysaccharide (K14 antigen) from Escherichia coli 06:K14:H31.

The chemical structure of the K14-antigenic polysaccharide (K14 antigen) of Escherichia coli 06:K14:H31 was elucidated by determination of the composition, 1H- and 13C-n.m.r. spectroscopy, periodate oxidation, and study of the oligosaccharides obtained by partial hydrolysis. The polysaccharide consists of [O-(2-acetamido-2-deoxy-beta-D-galactopyranosyl)-(1 leads to 5)-O-(3-deoxy-beta-D-manno-octulopyranosylonic acid)-(2 leads to 6)] repeating units, approximately 60% of the octonic acid units being O-acetylated and approximately 10% O-propionylated at O-8. The sequence of acetylated and propionylated residues is not known. The serologically-specific part of the K14 antigen residues in the polysaccharide part.

Bacterial Capsules↗
PubMed1983

Cell-wall lipopolysaccharide of Escherichia coli 0114:H2. Structure of the polysaccharide chain.

The O-specific polysaccharide of the 0114 antigen (lipopolysaccharide) of Escherichia coli 0114 and oligosaccharides obtained from it by Smith degradation and hydrogen fluoride solvolysis were analyzed, using proton and 13C nuclear magnetic resonance spectroscopy and methylation. The results indicated that the 0114 polysaccharide has the tetrasaccharide repeating unit alpha-N-acetylglucosamine(1 leads to 4) beta-3,6-dideoxy-3-(N-acetyl-L-seryl)aminoglucose(1 leads to 3) beta-ribofuranose(1 leads to 4)galactose. In the polysaccharide the repeating units are joined through beta 1 leads to 3-galactosyl linkages. This structure is compared with that of the serologically cross-reacting Shigella boydii 08 antigen and the serological similarity is discussed.

Cell Wall↗
PubMed1982

Structure of the Escherichia coli K2 capsular antigen. Stereochemical configuration of the glycerophosphate and distribution of galactopyranosyl and galactofuranosyl residues.

The Escherichia coli K2 capsular antigen is known to be composed of alpha-D-galactopyranosyl(1--2)glycerophosphate and alpha-D-galactofuranosyl(1--2)glycerophosphate units which are connected by phosphodiester bonds to C-4 of the galactopyranosyl and C-5 or C-6 of the galactofuranosyl moieties. In the present study the glycerophosphates were released by two different procedures and shown to have the sn-glycero-3-phosphate stereochemical configuration. In the first, the chain was fragmented by Smith degradation to glycerophosphothreitol from which the glycerophosphate was released by alkali hydrolysis. The structure-dependent low recovery of alpha-glycerophosphate (less than 10%) initiated the development of another degradative sequence which consisted of periodate oxidation, beta elimination, hydrazinolysis, and alkaline treatment. This way, approximately 90% of the glycerophosphate was released as sn-glycero-3-phosphate. beta elimination revealed in addition that most of the galactofuranosyl residues carry the phosphodiester bond at position 5. Separation by gel permeation chromatography and analysis of the fragments obtained by beta elimination showed that pyranosidic and furanosidic galactosyl residues alternate in the same chain and suggested the sequences Galf(p)GroP-(GalpGroP)n-Galf- and -GalfGroP-(GalpGroP)n-Galf-, where n is 6, 4, and 3, respectively.

Antigens↗