The Lipopolysaccharide from Pseudomonas aeruginosa NCTC 8505

Abstract

Structural studies have been carried out on the 0-specific fraction from the lipopolysaccharide of Pseudomonas aeruginosa NCTC 8505, Habs serotype 03. The 0-specific polysaccharide has a tetrasaccharide repeating-unit containing residues of L-rhamnose (Rha), 2-acetamido-2-deoxy-~-glucose (GlcNAc), 2-acetamido-2-deoxy-~-galacturonic acid (GalNAcA), and 2,4-diacetamid0-2,4,6-trideoxy-i~-glucose (BacNAc,). The following structure has been assigned to the repeating-unit :The parent lipopolysaccharide is a mixture of S, R, and SR species, and its high phosphorus content is partly due to the presence of triphosphate residues, as found for other lipopolysaccharides from P. aeruginosa. In addition to phosphorus, heptose, a 3-deoxyoctulosonic acid, and amide-bound alanine, the core oligosaccharide contains glucose, rhamnose, and galactosamine (molar proportions 3 : 1 : 1). The rhamnose and part of the glucose are present as unsubstituted pyranoside residues: other glucose residues are 6-substituted. We have previously reported general analyses of the lipopolysaccharide from P. aeruginosa NCTC 8505 [19], belonging to Habs serogroup 03, and identified the amino sugars present in the 0-specific fraction [20,21]. Here we describe the results of further studies of these products, including evidence for the structure of the 0-specific polysaccharide. MATERIALS AND METHODS Isolation and Fractionation of LipopolysaccharideMethods used for the batch culture of Pseudomonas aeruginosa NCTC 8505, the preparation of cell walls, and the Abbreviations. BacNAc,, 2,4-diacetamido-2,4,6-trideoxygluccse (NN-diacetylbacillosamine); GalNAcA, 2-acetamido-2-deoxygakacturonic acid; GlcNAc, 2-acetamido-2-deoxyglucose; Rha, rhamnose.

Somatic antigens of Pseudomonas aeruginosa

“…c) In the spectrum of the polysaccharide there is only one signal (6 = 55.0 ppm) in the region (6 = 52.5-55.5 ppm) expected [lo] for C-2 of 2-amino hexopyranoses with the a-gluco configuration, whereas two such monosaccharides (N-acetylglucosamine and N,N'-diacetylbacillosamine) were claimed to be present [5].…”

“…Although support for this assignment was provided by Cr03 oxidation of the acetylated polysaccharide (destruction of rhamnose), there were problems in interpretation of the 13C-NMR spectrum (see [5] and below).…”

“…Lipopolysaccharide and 0-specific polysaccharide from strain NCTC 8505 were isolated as described previously [5].…”

“…It contained the signals for methyl groups of two 6-deoxy sugars at 1.29 ppm and 1.22 ppm (d, J5,6 6 Hz for both), four acetamido groups at 2.06 (3H, s) and 1.98 ppm (9H, s), and four anomeric protons at 5.32 ppm (d, Jl,2 3 Hz), 5.24 ppm (d, J1,2 4 Hz), 4.81 ppm (broad signal), and 4.66 ppm (d, J1,2 7.5 Hz). The 3C-NMR spectrum of the polysaccharide [5] showed the signals for C-6 of two 6-deoxy sugars at 18.3 ppm and 17.8 ppm, a carboxyl group at 174.0 ppm, four acetamido groups (23.1 -23.5 ppm for CH3 and 175.2-175.4 ppm for CO), four anomeric carbons at 98 -104 ppm, four carbons carrying nitrogen in the range 50-58 ppm, and thirteen carbons carrying oxygen in the range 66-82 ppm (Table 1). These data are in accord with the monosaccharide composition proposed for the polysaccharide [5], with a tetrasac- The 'H-and 13C-NMR spectra of the Wokatsch 013 polysaccharide were identical to those of the NCTC 8505 polysaccharide.…”

“…Recently [5], the following structure was proposed for the 0-specific polysaccharide from strain NCTC 8505.…”