title: On-resin convergent synthesis of a glycopeptide from HIV gp120 containing a high mannose type N-linked oligosaccharide.
abstract: This chapter describes a rapid and efficient approach for the solid-phase synthesis of N-linked glycopeptides that utilizes on-resin glycosylamine coupling to produce N-linked glycosylation sites. In this method, the full-length nonglycosylated peptide is first synthesized on a solid-phase support using standard Fmoc chemistry. The glycosylation site is then introduced through an orthogonally protected 2-phenylisopropyl (PhiPr) aspartic acid (Asp) residue. After selective deprotection of the Asp residue, a high mannose type oligosaccharide glycosylamine is coupled on-resin to the free Asp side chain to form a N-glycosidic bond. Subsequent protecting group removal and peptide cleavage from the resin ultimately yields the desired glycopeptide. This strategy provides an effective route for conducting glycosylation reactions on a solid-phase support, simplifies the process of glycopeptide purification relative to solution-phase glycopeptide synthesis strategies, and enables the recovery of potentially valuable, un-reacted oligosaccharides. This approach has been applied to the solid-phase synthesis of the N-linked high mannose glycosylated form of peptide T (ASTTTNYT), a fragment of the HIV-1 envelope glycoprotein gp120.
authors.forename: Rui
authors.initials: R
authors.lastname: Chen
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Tolbert
mesh_terms: D000595:Amino Acid Sequence; D001224:Aspartic Acid / Q000737:chemistry; D001665:Binding Sites; D005944:Glucosamine / Q000737:chemistry; D006020:Glycopeptides / Q000138:chemical synthesis* / Q000737:chemistry* / Q000302:isolation & purification; D006031:Glycosylation; D015699:HIV Envelope Protein gp120 / Q000737:chemistry*; D008358:Mannose / Q000737:chemistry*; D009844:Oligosaccharides / Q000737:chemistry*; D012117:Resins, Synthetic / Q000737:chemistry*
chemical_list: D006020:Glycopeptides; D015699:HIV Envelope Protein gp120; D009844:Oligosaccharides; D012117:Resins, Synthetic; C514793:gp120 protein, Human immunodeficiency virus 1; D001224:Aspartic Acid; D005944:Glucosamine; D008358:Mannose