The Structure of the Capsular Polysaccharide (K5 Antigenn) of Urinary-Tract-Infective Escherichia coli 010:K5:H4. A Polymer Similar to Desulfo-Heparin

Abstract

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‐β‐glucuronyl‐1,4‐α‐N‐acetylglucosaminyl unit. This structure is similar to that of desulfo‐heparin.