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CLICKING SUGARS ONTO SUGARS:
OLIGOSACCHARIDE ANALOGS AND
GLYCOCLUSTERS ON
CARBOHYDRATE SCAFFOLDS
MARIA LAURA UHRIG AND JOSE KOVENSKY
5.1
INTRODUCTION
Many biologically relevant macromolecules are composed of carbohydrates.
Oligosaccharides are commonly found as glycoconjugates having specific roles inside
the cell, or exposed on the cell surface to the extracellular media, taking part in
remarkable recognition features. The different arrangements of the residues, in terms
of glycosylated positions, stereochemistry, and substitution, allow a huge diversity
of structures. It is often said that they serve to “decorate” mainly proteins and lipids,
as a way to signify the relevance of the structure diversity of carbohydrates in many
pathological and physiological processes.
The recognition of the different oligosaccharide structures by specific receptors
(i.e., proteins), trigger many biological events. For example, cell-cell recognition and
adhesion processes, and also signal transduction pathways and their modulation, are
direct consequences of the exposition of certain sugars linked in specific ways [1]. In
the case of many proteins and lipids, their functionality depends exclusively on the
presence or absence of the oligosaccharidic chain.
Among carbohydrate-protein interactions, those involving lectins modulate many
biological events including inflammation [2], immune response, apoptosis, tumor
metastasis or viral and bacterial infections [1c-f, 3, 4]. It is well known that lectins
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