Glucose dehydrogenase: a new oxidising enzyme from animal tissues

THE preparation and properties of an enzyme which oxidises hexosediphosphate have already been described [Harrison, 1931]. During the course of this work, experiments were carried out to see whether the oxidation of hexosediphosphate was affected by the addition of other substances. Sub- stances similar in structure to hexosediphosphate might, from the work of Quastel and Wooldridge [1928], be expected to be adsorbed at the same enzyme surface and so inhibit the oxidation. One of the substances tested was glucose, and it was surprising to find that this substance produced not an inhibition but a marked acceleration. Further investigation showed that there is present in the hexosediphosphate enzyme preparation another enzyme capable, in the presence of a suitable hydrogen acceptor, of bringing about the oxidation of glucose. Since an enzyme which oxidises glucose has not apparently been hitherto obtained from animal tissues, it seemed desirable to study its prepara- tion and properties in some detail. It has been found possible to obtain per- fectly clear solutions of the enzyme capable of being filtered through a porcelain filter without loss of activity.