Gram-negative bacteria including Escherichia coli, Citrobacter rodentium, Salmonella typhimurium, and Shigella flexneri are sensed in an ill-defined manner by intracellular inflammasome complex that activates caspase-11. We show macrophages loaded with synthetic lipid A, E. coli lipopolysaccharide (LPS), or S. typhimurium LPS activate caspase-11 independently of the receptor Toll-like 4 (TLR4). Consistent A triggering noncanonical inflammasome, containing a divergent structure antagonized...

Cells in a plant differentiate according to their positions and use cell-cell communication assess these positions. Similarly, single cells suspension cultures can develop into somatic embryos, is thought control this process. The monoclonal antibody JIM8 labels an epitope on specific plants. also certain carrot embryogenic cultures. We have used secondary antibodies coupled paramagnetic beads label immunomagnetically sort culture pure populations. the JIM8(+) population whereas JIM8(-) do...

The structure of lipid A from the lipopolysaccharide Rhizobium leguminosarum bv.phaseoli (wild type strain CE3) was investigated by alkylation analysis, nuclear magnetic resonance spectroscopy, and electrospray fast atom bombardment mass spectrometry de-0acylated A. carbohydrate backbone shown to be a trisaccharide containing galacturonic acid, glucosamine, unique sugar 2-amino-2-deoxygluconic previously unreported in lipopolysaccharides.Nuclear spectroscopy ethylation analyses revealed that...

The nodulation genes of rhizobia are regulated by the nodD gene product in response to host-produced flavonoids and appear encode enzymes involved production a lipo-chitose signal molecule required for infection nodule formation. We have identified nodZ Bradyrhizobium japonicum, whose is addition 2-O-methylfucose residue terminal reducing N-acetylglucosamine signal. This substitution essential biological activity this molecule. Mutations result defective siratro. Surprisingly, although...

Helicobacter pylori (H. pylori) is the strongest known risk factor for gastric carcinogenesis. One cancer-linked locus cag pathogenicity island, which translocates components of peptidoglycan into host cells. NOD1 an intracellular immune receptor that senses from Gram-negative bacteria and responds by inducing autophagy activating NF-κB, leading to inflammation-mediated bacterial clearance; however chronic pathogens can evade NOD1-mediated clearance altering structure. We previously...

The current work reports protein extraction from Spirulina platensis cyanobacterial biomass in order to simultaneously generate a potential co-product and biofuel feedstock with reduced nitrogen content. S. cells were subjected cell disruption by high pressure homogenization subsequent isolation solubilisation at alkaline pH followed precipitation acidic pH. Response surface methodology (RSM) was used optimize the process parameters - pH, (solubilisation/precipitation) time concentration for...

The structural arrangement of oligosaccharides comprising the core region Rhizobium etli CE3 lipopolysaccharide (LPS) has been elucidated through characterization LPSs from two R. mutants. One mutant, CE358, completely lacks O-chain polysaccharide, while second CE359, contains a truncated portion this polysaccharide. This in these was determined using electrospray ionization mass spectrometry, tandem and methylation analysis. Mild acid hydrolysis CE359 LPS produces major oligosaccharides:...

Chem 243, 433243411, permethylation and hydrolysis of the molecule do not yield 2,4,6-tri-O-methylglucose. This suggests that there is no 3-0-monosubstituted glucose unit in chain.The present study shows that, instead, this doubly substituted positions 3 4 such it yields 2,6-di-O-methylglucose on methylation.Periodate oxidation polysaccharide followed by reduction acid gives equimolar amounts 3-O-methylglucose, 6-0-methylglucose, glucose.Methylation analysis oxidized reduced product...

The prominent host muramidase lysozyme cleaves bacterial peptidoglycan (PG), and the enzyme is abundant in mucosal secretions. lytic susceptibility of Gram-negative bacteria mechanisms they use to thwart activity are poorly studied. We previously characterized a Helicobacter pylori PG modification enzyme, an N-deacetylase (PgdA) involved resistance. In this study, another putative O-acetyltransferase (PatA), was identified. Mass spectral analysis purified demonstrated that patA strain...

Six at one blow! The creation of small oligosaccharide libraries was achieved by a new strategy random glycosylation nonprotected sugars. With tri‐ O ‐benzyl‐ L ‐fucopyranosyl trichloroacetimidate as donor and βGal(1 → n )βGlcNAcOR ( = 3, 4, 6; R (CH 2 ) 8 OC 6 H 4 ‐ p ‐OMe) acceptors, all six trisaccharides form in DMF roughly equal quantities. It is astounding that free OH groups are fucosylated similar rate.

Rhizobia are nitrogen-fixing bacteria that establish endosymbiotic associations with legumes. Nodule formation depends on various bacterial carbohydrates, including lipopolysaccharides, K-antigens, and exopolysaccharides (EPS). An acidic EPS from Rhizobium sp. strain NGR234 consists of glucosyl (Glc), galactosyl (Gal), glucuronosyl (GlcA), 4,6-pyruvylated (PvGal) residues beta-1,3, beta-1,4, beta-1,6, alpha-1,3, alpha-1,4 glycoside linkages. Here we examined the role genes in synthesis EPS....

Structural modification of peptidoglycan (PG) is one the mechanisms that pathogenic bacteria use to evade host innate immune system. For noninvasive human gastric pathogen Helicobacter pylori, PG delivery cells trigger response. H. pylori HP310 was markedly up-expressed upon cell exposure oxidative stress. However, disruption did not produce a phenotype distinguishable from parent, including stress resistance characteristics. shows very weak homology known gene pgdA encoding deacetylase in...

The O-antigenic polysaccharide of the<i>Rhizobium etli</i> CE3 lipopolysaccharide (LPS) was structurally characterized using chemical degradations (Smith degradation and β-elimination uronosyl residues) in combination with alkylation analysis, electrospray, matrix-assisted laser desorption ionization-time flight mass spectrometry, tandem ¹H COSY TOCSY nuclear magnetic resonance spectroscopy analyses the native derived oligosaccharides. found to be a unique, relatively low...

To determine whether glycoconjugates can be released into airways by surface epithelial cells that do not contain secretory granules and, if so, extracellular proteinases affect this release, we studied dog tracheal after 8–10 days in culture. Ultrastructurally, these showed an extensive cell coat and no granules. Cells were pulse labeled with radioactive sulfate (Na2 35SO4 50 μCi/ml/24 h) washed free of the unbound label. Release sulfated products was then measured at 20-min intervals under...

Secondary cell wall polysaccharides (SCWPs) are important structural components of the Bacillus and contribute to array antigens presented by these organisms in both spore vegetative forms. We previously found that antisera raised anthracis preparations cross-reacted with SCWPs isolated from several strains pathogenic B. cereus, but did not react other phylogenetically related nonpathogenic Bacilli, suggesting SCWP cereus share specific features. In this study, three causing severe or fatal...

Bacillus anthracis CDC 684 is a naturally occurring, avirulent variant and close relative of the highly pathogenic B. Vollum. contains both virulence plasmids, pXO1 pXO2, yet non-pathogenic in animal models, prompting closer scrutiny molecular basis attenuation. We structurally characterized secondary cell wall polysaccharide (SCWP) (Ba684) using chemical NMR spectroscopy analysis. The SCWP consists HexNAc trisaccharide backbone having identical structure as that Pasteur, Sterne Ames,...

ABSTRACT Judged by migration of its lipopolysaccharide (LPS) in gel electrophoresis, the O antigen Rhizobium etli mutant strain CE166 was apparently normal size. However, LPS sugar composition and staining bands after electrophoresis indicated that proportion molecules possessed only 40% wild-type value. Its also differed from wild type lacking quinovosamine (2-amino-2,6-dideoxyglucose). Both these defects were due to a single genetic locus carrying Tn 5 insertion. The deficiency O-antigen...

Many early molecular events in symbiotic infection have been documented, although factors enabling Rhizobium to progress within the plant-derived thread and ultimately survive intracellular symbiosome compartment as mature nitrogen-fixing bacteroids are poorly understood. Rhizobial surface polysaccharides (SPS), including capsular (K-antigens), exist close proximity membranes throughout process. SPSs essential for bacterial survival, adaptation, potential determinants of nodulation and/or...

A broad-host-range endosymbiont,Sinorhizobium sp. NGR234 is a component of several legume-symbiont model systems; however, there little structural information on the cell surface glycoconjugates. cells in free-living culture produce major rough lipopolysaccharide (LPS, lacking O-chain) and minor smooth LPS (containing O-chain), structure lipid components was investigated by chemical analyses, mass spectrometry, NMR spectroscopy underivatized lipids A. The from heterogeneous consists six...

Endolysins are bacteriophage enzymes that lyse their bacterial host for phage progeny release. They commonly contain an N-terminal catalytic domain hydrolyzes peptidoglycan (PG) and a C-terminal cell wall-binding (CBD) confers enzyme localization to the PG substrate. Two endolysins, lysin L (PlyL) G (PlyG), specific Bacillus anthracis. To date, wall ligands CBD have not been identified. We recently described structures number of secondary polysaccharides (SCWPs) from B. anthracis cereus...