UBC Theses and Dissertations
Structural studies on Klebsiella capsular polysaccharides Folkman, Timothy Edward
To date, studies have revealed that seventy-eight serologically distinct strains of Klebsiella bacteria exist. The antigenic character of each strain in an immunological reaction is considered to be determined by the capsular polysaccharide which surrounds the bacterial cell. Structures of the capsular polysaccharides from well over half the known Klebsiella strains have been established; all of them unique. In a continuing program to elucidate the chemical structures of these polysaccharides in order to explain immunological responses, evidence for the structure of the antigens from Klebsiella serotypes K17 and K44 is presented. Methylation analysis was used to establish linkage positions of the monosaccharide units. Uronic acid degradation, periodate oxidation-Smith degradation, and partial hydrolysis were the techniques employed to generate and study oligosaccharides from the more complex polymer. Extensive use was made of ¹H and ¹³C nuclear magnetic resonance spectroscopy to indicate anomeric configurations of the oligo- and polysaccharides alike. Methods such as gas liquid chromatography, gas liquid chromatography-mass spectrometry, gel filtration chromatography, paper chromatography, and polarimetry have been used to isolate and identify the products obtained from the various degradative techniques. Although the polysaccharides of K-types 17 and 44 are part of a small group with the same qualitative composition, their structures are found to consist of the following dissimilar repeating units: [2 diagrams of chemical structures] The latter represents pentasaccharide repeating saccharide. the first unit in a example of Klebsiella a linear capsular poly-saccharide.
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