Lectin-Ligand Interactions

Raff Is there any precedent for a lectin—ligand interaction on a receptor in any other system ... 

A number of specific components contribute to the complex energetics of lectin-ligand interactions. The observed affinities (functional affinities, see Section ll.B.l)... 

Surface plasmon resonance (SPR) is an analytical method that can be used to evaluate protein-ligand interactions. It has only recently been applied to probe lectin-ligand interactions [11,61-66]. In SPR, the amount of material bound to a surface is quantified by monitoring the absorption of an evanescent wave. One binding partner is attached to the surface by covalent or noncovalent interactions, and its counterpart... 

Recent developments are pushing towards elucidating complex binding phenomenon between clustered carbohydrate epitopes and multivalent lectins. Ligand valency often results in aggregation, and the kinetic of the process may complicate the ITC measurements.86 For polymers presenting multiple carbohydrate epitopes, such as mucins, it has been proposed that the enhanced affinity observed for these interactions are due to internal diffusion of lectin molecules from epitope to epitope in these multivalent ligands before dissociation.87,88... 

Because they are easily accessible, glycans displayed on the surface of mammalian cells provide enormous opportunities to bind to many microbial pathogens, ranging from viruses to molecular toxins and from pathogenic bacteria to parasites. In multivalent binding, multiple interactions between ligands and various receptors are common (Fig. 16.1). One representative example is ricin—a versatile and durable A-B-type toxin—in which one of the protein chains (the B chain) is a lectin that interacts and binds terminal galactose (Gal) on the surface of eukaryotic cells with multivalent interactions to facilitate entry of the other peptide chain (the A chain) into the cell to cause cellular death via the catalytic... 

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