Immobilization of enzymes on aldehydic matrices by reductive alkylation

We report here a convenient and inexpensive method of attaching enzymes to solid supports which contain diols. Dextran coated porous glass, Sepharose and glass coated with a glyceryl silane were oxidized with NaIO 4. Trypsin, carboxypeptidase A, and carboxypeptidase B were bound to the oxidized supports by treatment with NaBH 4. The pH dependence of the coupling reaction and loss of lysine in bound trypsin indicate that the immobilization occurs via reductive alkylation. The bound enzymes display good catalytic activity against synthetic substrates and proteins.