SYNTHESIS AND CONFORMATIONAL-ANALYSIS OF N-GLYCOPEPTIDES THAT CONTAIN EXTENDED SUGAR CHAINS

[摘要] Maltooligosaccharides with 2-7 sugar moieties were converted into beta-1-amino-1-deoxy derivatives and were coupled to N-alpha-fluorenylmethoxycarbonyl-L-aspartic acid alpha-tert-butyl beta-pentafluorophenyl ester. After trifluoroacetic acid deprotection, the resulting glycosylated asparagines were used as building blocks for the solid-phase synthesis of T-cell epitopic glycopeptide analogues. The coupling efficiencies of the glycoamino acid synthons and the acid and base stability of the resulting glycopeptides indicate the applicability of this solid-phase synthetic protocol for the incorporation of sugars that are comparable in size with that of the natural carbohydrate antennae of N-glycoproteins. The sugars placed into N-terminal position did not affect the strong alpha-helical structure of the peptides, but inhibited the disulfide-bridge formation of proximal cysteine residues in a carbohydrate length-dependent manner.

[发布日期] 1994-02-21