Chemical Synthesis of N-Linked Glycans Carrying Both Mannose-6-phosphate and GlcNAc-Mannose-6-phosphate Motifs
摘要:
Mannose-6-phosphate (M6P) containing N-linked glycans are the essential targeting signals for hydrolases sorting in eukaryotic cells. To facilitate their structural and binding analyses, a highly efficient and convergent method has been developed to prepare complex N-linked glycans with well-defined M6P and N-acetylglucosamine (GlcNAc)-M6P motifs, a newly identified binding element for M6P receptors. The GlcNAc-M6P motif was stereoselectively installed at the late stage of the synthesis. Sequential deprotection of benzyl and acetate groups provided the fully deprotected N-glycans in excellent yield.
Synthesis of Proteophosphoglycans of <i>Leishmania </i><i>m</i><i>ajor</i> and <i>Leishmania </i><i>m</i><i>exicana</i>
作者:Debatosh Majumdar、Galal A. Elsayed、Therese Buskas、Geert-Jan Boons
DOI:10.1021/jo048443z
日期:2005.3.1
A novel approach for the synthesis of various fragments of proteophosphoglycans from Leishmania major and Leishmania mexicana proteophosphoglycans has been developed. These compounds have been obtained by coupling alpha-mannosyl and alpha-acetyl-glucosamine phosphoramidite derivatives with the serine hydroxyl of various amino acids and peptides to give, after oxidation with tert-BuOOH, phosphotriesters exclusively as alpha-anomers in good yield. The resulting compounds could be deblocked using conventional methods. Glycophosphorylation of preassembled and properly protected peptides was found to be more efficient for the preparation of proteophosphoglycan fragments than a building block approach strategy using a phosphoglycosylserine derivative.