ENZYME-IMMOBILIZATION BY THE GLUTARDIALDEHYDE PROCEDURE - AN INVESTIGATION OF THE EFFECTS OF REDUCING THE SCHIFF-BASES GENERATED, AS BASED ON STUDYING THE IMMOBILIZATION OF GLUCOSE-OXIDASE TO SILANIZED CONTROLLED PORE GLASS

The effects of reducing the Schiff-bases formed when enzymes are immobilized by the glutardialdehyde procedure are investigated in order to evaluate if such treatment offers any significant advantages in respect to improved immobilization characteristics such as increased activity, better tolerance to media of elevated pH values, and improved time stability. As reducing agents sodium borohydride and sodium cyanoborohydride are employed. The study is made on glucose oxidase immobilized to controlled pore glass beads. The individual enzyme preparations are packed into column reactors of similar size and sequentially incorporated into a flow injection system. Detection of the hydrogen peroxide formed by injection of glucose samples is accomplished by chemiluminescence. Following subjection to various pretreatments, the response characteristics of the individual reactors are recorded. It is concluded that reduction with sodium borohydride has virtually no effects at all, while that of sodium cyanoborohydride is merely marginal as compared with the non-reduced enzyme preparation.