Affinity ligands Biospecific

Figure 6.14 Schematic representation of the principle of biospecific affinity chromatography. The chosen affinity ligand is chemically attached to the support matrix (agarose bead) via a suitable spacer arm. Only those ligands in solution that exhibit biospecific affinity for the immobilized species will be retained...

Figure 14.9. Model of species present during the biospecific elution of biomolecule A from a column having immobilized affinity ligand X, using ligand L.

The distribution of bonded molecules is a very important parameter for bioaffinity sorbents. Evidently, biospecific binding is dramatically dependent not only on the spatial disposition of bonded affinity ligands, but even on the number of ligand-surface bonds (one - or more) [41]. 

Macromolecules bearing reactive groups in the repeat units along their chains are capable of multiple interaction with the matrix. As early as 1973, Wilchek prepared Sepharose-based supports chemically modified by chemisorbed polylysine and polyvinylamine [41]. The leakage of dyes covalently bonded to these supports was reduced remarkably as compared to non-modified Sepharose activated by cyanogen bromide. Thus, stable and high capacity affinity adsorbents could be prepared by the introduction of macromolecular spacers between a matrix and a biospecific ligand. 

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