APPLICATION OF A QUINOHEMOPROTEIN ALCOHOL-DEHYDROGENASE IN BIO-ELECTROCATALYSIS - IMMOBILIZATION OF THE ENZYME AND MEDIATED ELECTRON-TRANSFER BETWEEN THE ENZYME AND AN ELECTRODE

Quinohaemoprotein alcohol dehydrogenase from Comamonas testosteroni wa s immobilized on polypyrrole-coated track-etch and microporous membran es. On the track-etch membrane, 3.4 to 4.8 x 10(-3) Units of enzyme/cm 2 was immobilized whilst on the microporous membrane 0.05 U/cm2 was im mobilized. The track-etch membrane was then used in electrochemical st udies using ferricyanide as a redox mediator giving a maximum catalyti c current of 0.022 mA/cm2 membrane with 1-pentanol as the substrate. T he kinetic parameters (K(m) and V(max)) of the immobilized enzyme are of the same order of magnitude as those of the free enzyme.