Progress Towards Identifying The GalfNAc-Transferase In The Biosynthesis Of Campylobacter jejuni Strain NCTC11168H Capsular Polysaccharide

• C. jejuni GalfNAc Transferase

• Author / Creator

  Jayasuriya, Anushka, B.

• Campylobacter jejuni (C. jejuni) is currently the leading cause of food-borne gastroenteritis, and is a precursor to Guillian–Barré and Miller–Fischer syndromes. C. jejuni produces a number of unusual carbohydrates on its cell surface that are essential to viability and pathogenicity. Of particular interest is the C. jejuni strain 11168H capsular polysaccharide (CPS), which, in addition to having a structurally interesting tetrasaccharide repeating unit, is a virulence factor. The tetrasaccharide consists of β-D-ribofuranose (Ribf), 2-acetamido-2-deoxy-β-D-galactofuranose (GalfNAc), α-Dglucopyranosiduron-(2-amino-2-deoxyglycerol)-amide (GlcANGro), and 6-O-methyl-D-glycero-α-L-gluco-heptopyranose (Hep) residues. Inhibitors of CPS biosynthesis are attractive therapeutic targets in circumventing C. jejuni associated diseases. However, there remain many questions in regard to the mechanism by which the C. jejuni CPS is biosynthesized, and without a proper understanding and identification of the enzymes that catalyze the synthesis of this tetrasaccharide, producing effective inhibitors remains problematic. The aim of this project was to address some of these deficiencies. The main focus was to identify the GalfNAc transferase that catalyzes the coupling of the GalfNAc onto the GlcANGro in the tetrasaccharide repeating unit. This involved cloning and expressing putative GTs in the cps gene cluster (cj1438, 1440, and 1442), as well as chemically synthesizing potential donor and acceptor substrates to test with these enzymes. It concluded with an enzymatic assay designed to probe for GalfNAc transferase activity.

• Subjects / Keywords

  • Glycosyltransferase
  • Glycomics
  • Carbohyrdate chemistry

• Graduation date

  Spring 2016

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R3B27PW9K

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.