Abstract
Chemical modification and immobilization of enzymes have been usually considered unrelated tools to improve biocatalyst features. However, there are many examples where a chemically modified enzyme is finally used in an immobilized form, and that exemplifies how both tools may be complementary resulting in a synergism in the final results. In this review we present some of the strategies that may give that result. For example, the chemical modification of soluble enzymes may be used to improve their immobilization (reinforcing adsorption or improving multipoint covalent attachment), or just to improve enzyme stability and facilitate the selection of the immobilization conditions. Chemical modification of previously immobilized enzymes benefits from solid-phase chemistry due to the nature of enzymes (e. g., prevention of inactivation, aggregation, etc.). The use of different targets for chemical modifications with small molecules or multifunctional polymers are also discussed: intramolecular or intersubunit cross-linking, one-point modification, generation of artificial microenvironments, etc.