Salmonella typhimurium chain

Tetra, octa, and dodecasaccharides have been prepared from Salmonella typhimurium lipopolysaccharide by specific degradation of the O chain with phage enzyme. These oligosaccharides contain 1,2, or 3 chemical repeating units (Svenson and Lindberg, 1981). 

TABLE I. Salmonella typhimurium Infection in Calves Delayed Skin Reactivity with Specificity for O-Antigenic Polysaccharide Chain... 

Kwon, Y.M. and Ricke, S.C. 1998. Induction of acid resistance of Salmonella typhimurium by exposure to short-chain fatty acids. Applied and Environmental Microbiology 64 3458-3463. 

The repeating unit of the O-specific polysaccharide side-chains of the Salmonella typhimurium antigenic outer bacterial cell wall is as follows ... 

Concerted Feedback Regulation. This type is also known as multivalent or cooperative feedback regulation. Only one enzyme is involved but more than one end product must be present in excess to inhibit or repress to a significant degree. This type of control is exerted in the branched-chain amino acid pathway of Salmonella typhimurium (Freundlich et al., 1963). 

Lipopolysaccharides are considered to be composed of three segments, lipid A, the core polysaccharide and the antigenic side chains. The core polysaccharide, in turn, has an inner region (which is linked to lipid A) called the backbone sequence and an outer core to which the antigen chains are attached. The lipopolysaccharides of Salmonella typhimurium are the best known and they will be used here as examples. 

Goldman, R. C. and Leive, L. (1980) Heterogeneity of antigenic-side-chain length in lipopolysaccharide from Escherichia coli 0111 and Salmonella typhimurium LT2. Eur. J. Biochem. 107, 145-153. 

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