On-Resin Convergent Synthesis of a Glycopeptide from HIV gp120 Containing a High Mannose Type N-Linked Oligosaccharide

Abstract

Summary/Abstract This method describes a rapid and efficient approach for solid phase synthesis of N-linked glycopeptides which utilizes on-resin glycosylamine coupling to produce N-linked glycosylation sites (1). In this method, the full-length non-glycosylated peptide is first synthesized on solid phase 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 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 yield the desired glycopeptide. This strategy provides effective glycosylation reactions on the solid phase, simplifies glycopeptide purification relative to solution phase glycopeptide synthesis strategies, and enables 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 (2–3).

Analysis of carbohydrates and glycoconjugates by matrix‐assisted laser desorption/ionization mass spectrometry: An update for 2011–2012

“…O-to Sacyl shift. Alkyl thioester exchange (Zheng et al, 2011a) Glycopeptide from HIV gp120 containing a high mannose N-linked glycan TOF Practical details of an on-resin convergent synthesis (Chen & Tolbert, 2011) Glycopeptides linked to mono-, di-, and tetra-valent lipopeptides TOF/TOF (CHCA, DHB), ESI Synthesis aimed at a fully synthetic MUC1-based anticancer vaccine. Linkage (Cai et al, 2011a) Glycopeptide with MUC1 epitope TOF For improved recognition of tumorassociated mucin MUC1 (Lakshminarayanan et al, 2012) C-Glycosylated amino acids MALDI (DHB)…”