1. Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
2. Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602, United States
3. Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, United States
4. Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada T6G 2E1