Artículo del mes

A carbohydrate–protein interaction is a key step in many biological processes. This recognition event is, in several cases, one of the first selective steps that triggers a series of biological processes leading to biological functions. This interaction is characterised by a high selectivity, a dependence of divalent cations—most of the time calcium atoms—and a very low affinity. The way that nature overcomes this low affinity is based on a multivalent interaction between several copies of the receptor (lectins) and a multivalent presentation of the glycan ligand. Thus, the development of tools required to understand these biological events in which carbohydrates are involved lies in the design and preparation of carbohydrate multivalent systems. Unfortunately, there is not an ideal multivalent scaffold for this multivalent presentation of carbohydrates and a plethora of systems have been described in the literature. Often chemists are inspired by nature to create these carbohydrate clusters mimicking the multivalent presentation of these glycans in natural systems. Viruses such as HIV are spherical entities fully decorated with envelope glycoproteins. The glycans are the ligands responsible to interact, in a multivalent manner, with cell surface receptors and start a cascade of processes that lead to cell attachment, fusion and entry of the virus into the target cells.

Inspired by these events, we envisaged that a nanospherical scaffold covered by carbohydrates could constitute a reasonable mimic of the virus surface and therefore could be used to interact in a multivalent manner with cell surface receptors.