J. Biochem, 1967, Vol. 62, No. 3 373-383
© 1967 Japanese Biochemical Society
research-article |
A New Rhamnosyl Compound in Lipopolysaccharide Preparations of Escherichia coli
Isolation and Enzymatic Synthesis*
From the Department of Chemistry, Faculty of Science, Nagoya University Nagoya
A new rhamnosyl compound, rhamnosyl X, was isolated by mild-acid hydrolysis of a lipopolysaccharide obtained from E. coli K-12. This compound also exists in a lipopolysaccharide preparation obtained from E. coli JE1538, a smooth strain with antigen O-100. It was not found in the lipopolysaccharide of E. coli W3993, a strain defective in UDP-galactose. Studies on the properties of the isolated rhamnosyl X suggested that X is 2-keto-3-deoxyoctonate (KDO) and that the linkage between rhamnose and KDO may be 1 
5.
Incorporation of rhamnose from dTDP-uC-L-rhamnose into lipopolysaccharide was observed using extracts of E. coli 679–680, a K-12 mutant which lacks the enzyme activity for dTDP-rhamnose synthesis. The radioactive product of the enzyme reaction could not be distinguished after mild hydrolysis from rhamnosyl X isolated from the lipopolysaccharide of E. coli K-12.
*This work was supported by a research grant from the United States Public Health Service (AM-07588-02) A preliminary report of this work was presented at the 37th Annual Meeting of Japanese Biochemical Society (J. Japan. Biochtm. Soc. (in Japanese), 36, 573 (1964)).