tailieunhanh - Báo cáo khoa học: Structural studies of the capsular polysaccharide and lipopolysaccharide O-antigen of Aeromonas salmonicida strain 80204-1 produced under in vitro and in vivo growth conditions

Aeromonas salmonicidais a pathogenic aquatic bacterium and the causal agent of furunculosis in salmon. In the course of this study, it was found that when grownin vitro on tryptic soy agar,A. salmonicidastrain 80204-1 produced a capsular polysaccharide with the identical structure to that of the lipopolysaccharide O-chain polysaccharide. | Eur. J. Biochem. 271 4507-4516 2004 FEBS 2004 doi Structural studies of the capsular polysaccharide and lipopolysaccharide O-antigen of Aeromonas salmonicida strain 80204-1 produced under in vitro and in vivo growth conditions Zhan Wang1 Suzon Larocque1 Evgeny Vinogradov1 Jean-Robert Brisson1 Andrew Dacanay2 Marshall Greenwell2 Laura L. Brown2 Jianjun Li1 and Eleonora Altman1 Institute for Biological Sciences National Research Council of Canada Ottawa Canada 2Institute for Marine Biosciences National Research Council of Canada Halifax Canada Aeromonas salmonicida is a pathogenic aquatic bacterium and the causal agent of furunculosis in salmon. In the course of this study it was found that when grown in vitro on tryptic soy agar A. salmonicida strain 80204-1 produced a capsular polysaccharide with the identical structure to that of the lipopolysaccharide O-chain polysaccharide. A combination of 1D and 2D NMR methods including a series of 1D analogues of 3D experiments together with capillary electrophoresis-electrospray MS CE-ES-MS compositional and methylation analyses and specific modifications was used to determine the structure of these polysaccharides. Both polymers were shown to be composed of linear trisaccharide repeating units consisting of 2-acetamido-2-deoxy-D-galacturonic acid GalNAcA 3- N-acetyl-L-alanyl amido -3 6-dideoxy-D-glucose 3- N-acetyl-L-alanyl amido -3-deoxy-D-quinovose Qui3NAlaNAc and 2-ace- tamido-2 6-dideoxy-D-glucose 2-acetamido-2-deoxy-D-quinovose QuiNAc and having the following structure fi3 -a-D-GalpNAcA- 1fi3 -p-D-QuipNAc- 1fi4 -p-D-Quip3NAlaNAc- 1- n where GalNAcA is partly presented as an amide and AlaNAc represents N-acetyl-L-alanyl group. CE-ES-MS analysis of CPS and O-chain polysaccharide confirmed that 40 of GalNAcA was present in the amide form. Direct CE-ES-MS MS analysis of in vivo cultured cells confirmed the formation of a novel polysaccharide a structure also formed in vitro which was .