Immobilization of Enzymes on Inorganic Supports by Covalent Methods

Covalent binding of an enzyme to a support is probably the most interesting method of immobilization from an industrial point of view. In this methodology, the activated groups of the support react with some external functional groups of the protein (see Chapter 1 ). Generally, reaction between the protein and activated groups of the support takes place by means of surface amino and carboxyl groups because they are accessible and are not normally involved in essential structural or catalytic activity. Immobilization by covalent methods must be carried out in chemical conditions that are compatible with the stability properties of the proteins. Generally, this involves two steps, first, activation of the support and second, coupling of the enzyme to the activated support. Activated supports have unstable and reactive functional groups, and therefore, unless steps are taken to preserve the activated support, immobilization of the enzyme should follow immediately after activation of the support.