title: Synthesis of high-mannose 1-thio glycans and their conjugation to protein.
abstract: The oligosaccharides Man4 and Man5, substructures of the high-mannose glycans of HIV glycoprotein gp120, were synthesized with a terminal 1-thiomannopyranose residue. The anomeric thiol can be readily converted to an azidomethyl aglycone through reaction with dichloromethane and displacement with sodium azide. The resulting oligomannans were then conjugated to ubiquitin utilizing thiol alkylation or azide/alkyne reactive tethers of minimal length. By combining high efficiency conjugation reactions and a short tether, we sought to establish conjugation conditions that would permit high density clustering of oligomannans in conjugate vaccines that could produce antibodies able to bind gp120 and potentially neutralize virus. LC-UV-MS was used to separate, identify and quantify the ubiquitin glycoconjugates with differing degrees of oligomannan incorporation. Binding of the HIV protective monoclonal antibody 2G12 and concanavalin A to microtitre plates coated with glycoconjugates was measured by ELISA.
authors.affiliation: Alberta Glycomics Centre and the Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada. jjbailey@ualberta.ca.
authors.forename: Justin J
authors.initials: JJ
authors.lastname: Bailey
authors.forename: David R
authors.initials: DR
authors.lastname: Bundle
mesh_terms: D015699:HIV Envelope Protein gp120 / Q000737:chemistry*; D008358:Mannose / Q000031:analogs & derivatives* / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D011134:Polysaccharides / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: D015699:HIV Envelope Protein gp120; D011134:Polysaccharides; D008358:Mannose