These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Unusual lipopolysaccharide antigens of a Salmonella typhi oral vaccine strain expressing the Shigella sonnei form I antigen.
    Author: Seid RC, Kopecko DJ, Sadoff JC, Schneider H, Baron LS, Formal SB.
    Journal: J Biol Chem; 1984 Jul 25; 259(14):9028-34. PubMed ID: 6378905.
    Abstract:
    Salmonella typhi 5076-1C, a potential live, oral vaccine for protection against typhoid fever and Shigella sonnei shigellosis, expresses the S. sonnei form I antigen and normal S. typhi somatic antigens. Polysaccharide antigens of this galactose epimeraseless genetic derivative strain were hot phenol-water extracted from cells grown with (+gal) and without (-gal) galactose. Ultracentrifugation of the aqueous layer from (+gal) cells resulted in a lipopolysaccharide (LPS) pellet having core-linked S. typhi O-antigen but no core-linked form I antigen; the LPS from (-gal) cells lacked O-antigen. The form I antigen, obtained from the supernatant, was purified by alcohol precipitation and ion exchange chromatography. Unlinked form I and S. typhi O-polysaccharide antigens, both present in the (+gal) supernatant, were further separated by gel filtration. Chemical analyses revealed the 5076-1C form I antigen to be a polymer (Mr = 14,000-20,000) having O-disaccharide repeating units comprised of 2-acetamido-4-amino-2, 4,6-trideoxy-D-galactose and 2-acetamido-2-deoxy-L-altruronic acid. Unlike parental S. sonnei form I LPS, the 5076-1C form I antigen lacked core lipid A, had low phosphorus content, and migrated in polyacrylamide gels with lower relative mobility. In contrast to current concepts of LPS assembly, these data indicate that 5076-1C form I antigen is transported to the cell surface without covalent linkage to core lipid A, and exists as a polymerized, antigenic surface entity.
    [Abstract] [Full Text] [Related] [New Search]