Phosphate groups in lipopolysaccharides of Salmonella typhimurium rfaP mutants

FEBS Letters

Helander, Ilkka M.³  Kilpeläinen, Ilkka²  Vaara, Martti¹ 

[1] Department of Bacteriology and Immunology, The Haartman Institute, University of Helsinki, FIN-00014 Helsinki, Finland;Institute of Biotechnology, University of Helsinki, FIN-00014 Helsinki, Finland;VTT Biotechnology and Food Research, P.O. Box 1501, FIN-02044 VTT, Finland

关键词: Salmonella typhimurium;    Structure;    Lipopolysaccharide;    Outer membrane;    31P-NMR;   

DOI  :  10.1016/S0014-5793(97)00572-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Lipopolysaccharides (LPS) of Salmonella typhimurium rfaP mutants and of a galE strain as a control were subjected to analysis by ³¹P-NMR in order to assess the location of phosphate groups. This was done to obtain direct proof for our earlier finding by chemical analysis that phosphate was lacking in the core oligosaccharide part of the mutant LPS, whereas the core oligosaccharide normally contains several phosphate groups. Such phosphate deficiency has been associated with the increased susceptibility of the rfaP mutants to hydrophobic antibiotics and detergents. Analysis of the de-O-acylated LPS derivatives of S. typhimurium rfaP strains SH7770, SH8551, and SH8572 by ³¹P-NMR revealed an almost total lack of phosphate groups in the core oligosaccharide part, the LPS phosphates being largely accounted for by the two monophosphate monoesters of lipid A, linked to positions C-1 and C-4′ of the lipid A backbone. Core oligosaccharide-linked phosphates were detected in minor proportions only, indicating the presence of some normally phosphorylated core oligosaccharide, due to the inherently leaky nature of the mutation.

【 授权许可】

Unknown