Behaviors on gel-filtration and electrophoresis of 6-phosphogluconate dehydrogenase isozymes isolated from sweet potato

Sephadex G-200 gel-filtration of an enzymatic preparation fromsweet potato root tissue showed three activity peaks (I, IIand III) of 6-phosphogluconate dehydrogenase. Re-chromatographyof either Peak II or III produced two peaks corresponding toPeak II and III. Disc electrophoreses of the original preparation,Peak II, Peak III and the Peak II-like peak after re-chromatographygave idetical zymograms of the three isozymes which were notinterconvertible. ¹ Present address: Institute of Applied Microbiology, Universityof Tokyo, Bunkyo-ku, Tokyo 113, Japan. (Received May 30, 1972; )