Multivalent high avidity

Naturally occurring carbohydrate multivalent displays are widespread in nature and include mucins, pathogen, and mammalian cell surfaces. Lectins, carbohydrate-binding proteins, often present multiple repeat carbohydrate binding domains. The interaction of multivalent presentations can result in the formation of numerous simultaneous non-co-valent bonds that proceed to afford the observed high avidity of carbohydrates (153). 

Implicit within this framework is that the dissociation rate of a multivalent ligand is solely dependent on the concentration of the monovalently bound species. The concentration of the monovalently bound species, in turn, is dependent on the EM for an intramolecular multivalent interaction. This suggests that, with the use of multivalent interactions, complexes that combine high avidity with the possibility of kinetic control and reversibility can be made. 

Monomeric IgG is frequently a poor inhibitor of the aggregation by RF of red cells coated with aggregated IgG. This again, could be due either to the exposure of new determinants, reactive with RF, upon aggregation of IgG or to multivalent attachment of single IgM molecules to aggregates of IgG on the red cell surface multivalent attachment is associated with high avidity. 

---