pubmed:abstractText |
The chemical structure of the K52 antigenic capsular polysaccharide (K52 antigen) of Escherichia coli O4:K52:H- was elucidated by composition, nuclear magnetic resonance spectroscopy, methylation, periodate oxidation before and after graded acid hydrolysis and by oligosaccharide analysis. The polysaccharide consists of a backbone of alpha-galactose units interlinked between C1 and C3 by phosphodiester bridges. This poly(alpha-galactosyl-phosphate) is substituted at C2 of each galactose unit by beta-fructofuranose residues. About 80% of the galactose units are O-acetylated at C4 and about 10% of the fructose units are both O-acetylated and O-propionylated at C1. The K52 polysaccharide has an average molecular mass of 34 kDa, thus consisting of approximately 65 fructosyl-galactosyl-phosphate repeating units.
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