Affinity noncovalent

Affinity chromatography exploits the specific, high affinity, noncovalent binding of a protein to another molecule, the ligand. First, the ligand is covalently attached to an inert and porous matrix (such as Sepharose). The protein mixture is then... 

While the mechanisms of formation of noncovalent crosslinked lattices of lectins with multivalent carbohydrates and glycoproteins have been well investigated,15-17 the mechanisms associated with the enhanced affinities of lectins binding to multivalent carbohydrates and glycoproteins have been less well investigated until recently.18,19... 

Finally, the clusters were tested as inhibitors of hemagglutination of pig and rabbit erythrocytes by type-1 piliated UTI89 clinical isolate E. coli. The inhibition titer (IT), that is, the lowest concentration of the inhibitor at which no agglutination occurs, showed tetramer 51 to be the best inhibitor of hemagglutination, with an IT of about 3 fiM, or a factor of 6000 as compared to its affinity, and corresponding to 1000-fold better inhibition than that induced by D-mannose. Overall, tetravalent cluster 51 was the best noncovalent cross-linker of Con A and the best ligand known to E. coli K12 FimH. 

The content by weight of carbohydrate in glycoproteins may vary from only a few percent to over 50 percent in some proteins in mucous secretions. Although the function of the polysaccharide in most glycoproteins is unknown, in some cases it may provide hydrophilicity, recognition, and points of noncovalent interaction with other proteins through lectin-like affinity binding. 

Fig. 1. Preparation of configurational biomimetic imprinted networks for molecular recognition of biological substrates. A Solution mixture of template, functional monomer(s) (triangles and circles), crosslinking monomer, solvent, and initiator (I). B The prepolymerization complex is formed via covalent or noncovalent chemistry. C The formation of the network. D Wash step where original template is removed. E Rebinding of template. F In less crosslinked systems, movement of the macromolecular chains will produce areas of differing affinity and specificity (filled molecule is isomer of template).

Antibody avidity is commonly applied to antigen-antibody interaction, where multiple, weak, noncovalent bonds form between antigen and antibody. Avidity is distinct from affinity, which is a term used to describe the strength of a single bond. As such, avidity is the combined synergistic strength of bond affinities rather than the sum of bonds. 

Two very similar molecules are two different physical objects [40], Hence, chemical/ structural comparison of similarity is a subtle and relative concept that acquires significance in a well-defined reference physical context. In other words, it is necessary to define in what respect and to what extent two different molecules are similar. Molecular series of specific and selective ligands interacting, in vitro and in equilibrium conditions, with a specific receptor constitute a sophisticated example of chemical similarity-diversity classification. This classification is based on the experimental binding affinity (AG°) values that quantify a particular molecular recognition phenomenon, which is, essentially, a noncovalent process [41]. This implies,... 

---