Abstract
A chemoselective strategy for oligosaccharide-peptide ligation is described in which alpha-thio analogues of mucin-related glycoconjugates can be readily accessed through site-selective conjugate addition of complex oligosaccharide thiolates to dehydroalanine-containing peptides. The efficiency of the ligation is highlighted by the rapid convergent assembly of thio-isosteres of the four tumor-associated carbohydrate antigens, T(N), T, ST(N), and 2,6-ST, as a pair of diastereoisomers at the newly formed cysteine stereocenter. The process proceeds in high yield and with complete retention of the alpha-anomeric configuration.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Alanine / analogs & derivatives*
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Alanine / chemistry
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Antigens, Tumor-Associated, Carbohydrate / chemistry
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Cysteine / analogs & derivatives
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Glycopeptides / chemical synthesis*
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Glycosylation
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Mucins / chemical synthesis*
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Oligosaccharides / chemistry*
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Peptides / chemistry*
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Stereoisomerism
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Sulfhydryl Compounds / chemistry*
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Thiogalactosides / chemical synthesis*
Substances
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Antigens, Tumor-Associated, Carbohydrate
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Glycopeptides
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Mucins
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Oligosaccharides
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Peptides
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Sulfhydryl Compounds
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Thiogalactosides
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dehydroalanine
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Cysteine
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Alanine