The structure of the capsular polysaccharide (K5 antigen) of urinary-tract-infective Escherichia coli 010:K5:H4. A polymer similar to desulfo-heparin

Eur J Biochem. 1981 May 15;116(2):359-64. doi: 10.1111/j.1432-1033.1981.tb05343.x.


The capsular polysaccharide was isolated from Escherichia coli 010:K5:H4; it could not be obtained from a uncapsulated (K5-) mutant. It contains N-acetylglucosamine and glucuronic acid in a molar ratio of 1:1. Acid hydrolysis of the acidic polysaccharide as well as Smith degradation and degradation by deamination of the carboxyl-reduced polysaccharide suggested that the polysaccharide is composed of a disaccharide repeating unit. The data obtained by methylation analysis and nuclear magnetic resonance spectroscopy indicated that the repeating sequence of the capsular polysaccharide is the 4-beta-glucuronyl-1,4-alpha-N-acetylglucosaminyl unit. This structure is similar to that of desulfo-heparin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylation
  • Antigens / isolation & purification*
  • Antigens, Bacterial*
  • Antigens, Surface*
  • Carbohydrate Sequence
  • Carbohydrates / analysis
  • Escherichia coli / immunology*
  • Humans
  • Magnetic Resonance Spectroscopy
  • Mass Spectrometry
  • Methylation
  • Urinary Tract Infections / microbiology*


  • Antigens
  • Antigens, Bacterial
  • Antigens, Surface
  • Carbohydrates
  • K antigens