Multivalent presentation of carbohydrates by 3(14)-helical peptide templates: synthesis, conformational analysis using CD spectroscopy and saccharide recognition

Abstract

A well defined 3(14)-helical tetravalent beta-galactopeptide site-specific functionalised template (SSFT) 1 was prepared containing D-galactose units, with free anomeric carbons as the aldehyde tags, and was explored via ligation with different aminoxy sugars (alpha-/beta-D-glucose, alpha/beta-D-galactose, alpha-D-mannose and beta-D-lactose) to get 3(14)-helical carbohydrate-functionalised multivalent glycoconjugates 2-7. Preliminary recognition studies of tetramannosyl glycoconjugate 4 with a specific lectin (concanavalin A) using fluorescence anisotropy showed an increase in binding affinity and the multivalency effect was found to be increased by 6.5 times per glycan.