Structural investigation on the lipopolysaccharide of Escherichia coli rough mutant F653 representing the R3 core type

Abstract

The chemical structure of the core oligosaccharide of the lipopolysaccharide isolated from Escherichiu coli rough mutant strain F653, representing the enterobacterial R3 core type, was investigated by quantitative and methylation analyses, nuclear magnetic resonance spectroscopy, gas-liquid chromatography/mass spectrometry, and determined as

The C-terminal Domain of the Escherichia coli WaaJ Glycosyltransferase Is Important for Catalytic Activity and Membrane Association

“…To determine the precise LPS content in the samples, Kdo content was determined (20). Recognizing there is heterogeneity in Kdo content in the isolated R3 LPS (6,8), the measured Kdo values were entirely consistent with the calculated values for a homogeneous sample containing (on average) two Kdo residues (data not shown). For reactions, the LPS stock was thawed, vortexed to resuspend any precipitated LPS, and then placed at 55°C for at least 10 min to redissolve the LPS.…”

“…WaaJ is required for the addition of an ␣-1,2-glucose to the outer core OS in R3 E. coli (6) and Salmonella enterica serovar Typhimurium (7), which becomes the point of attachment for O antigen ( Fig. 1) (8,9).…”

Structural and Immunochemical Characterization of aNeisseria gonorrhoeae Epitope Defined by a Monoclonal Antibody 2C7; the Antibody Recognizes a Conserved Epitope on Specific Lipo-oligosaccharides in Spite of the Presence of Human Carbohydrate Epitopes

“…LOS samples were also de-O-acylated with anhydrous hydrazine by modifying the method by Haishima et al (25); LOS were treated in anhydrous hydrazine at room temperature (ϳ25°C) for 2 h. The resulting LOS were further treated with 4 M KOH for 4 h at 120°C for complete deacylation (25,26). Enzymatic treatments of WG, 15253, and JW31R LOS were done as described previously (10).…”

Structural study on the free lipid A isolated from lipopolysaccharide of Porphyromonas gingivalis

“…Chemical degradation and modification of lipid A. De-O-acylation and dephosphorylation of lipid A were performed by the method described previously (12). To prepare phosphoryl-methylated lipid A, free lipid A (10 mg) was dissolved in chloroform-methanol (3:1 [vol/vol]) and passed through a Dowex 50 (H ϩ ) column (0.6 by 4 cm).…”