Immobilization of enzymes on magnetic beads through affinity interactions.

The development of enzyme immobilization techniques that will not affect catalytic activity and conformation is an important research task. Affinity tags that are present or added at a specific position far from the active site in the structure of the native enzyme could be used to create strong affinity bonds between the protein structure and a surface functionalized with the complementary affinity ligand. These immobilization techniques are based on affinity interactions between biotin and (strept)avidin molecules, lectins and sugars, or metal chelate and histidine tag. Recent developments involve immobilization of tagged enzymes onto magnetic nanoparticles. These supports can improve the performance of immobilized biomolecules in analytical assay because magnetic beads provide a relative large numbers of binding sites for biochemical reactions resulting in faster assay kinetics. This chapter describes immobilization procedures of tagged enzymes onto various magnetic beads.