[Synthesis and properties of carrier-fixed enzymes. VII. Linking of glucoamylase to dialdehyde cellulose, carboxymethylcellulose hydrazide and carboxymethylcellulose azide].

Glucoamylase (alpha-1,4-glucan glucohydrolase, EC 3.2.1.3) has been covalently linked to dialdehyde cellulose resulting in an immobilized enzyme containing 0.98% protein and an activity of 4.5 mg of the native enzyme per g of matrix, i.e. 46% relative activity. The complex lost its activity in continuous and batch hydrolysis of starch at 55 degrees C down to a limit of 18% of its original value. In contrast, the activity of the complex did not change when working at a temperature of 25 degrees C. Glucoamylase-carboxymethylcellulose complexes synthesized via carboxymethylcellulose hydrazide and azide, in contrast to MAEDA und SUZUKI [1], showed only an activity of 1 mg of the native enzyme per g of matrix. We did not succeed in coupling periodate-oxidized glucoamylase to carboxymethylcellulose hydrazide because the enzyme used lost nearly all of its activity already during periodate oxidation.