Purification and molecular weight determination of glucose-6-phosphate dehydrogenase and malic enzyme from mouse and Drosophila.

A facile two-step procedure was employed for simultaneous purification of glucose-6-phosphate dehydrogenase and malic enzyme from mouse (strain $\text{DBA}\text{2J}$) and Drosophila melanogaster. This involved the use of an 8-(6-aminohexyl)-amino-2′,5′-ADP-Sepharsoe affinity column chromatography followed by DEAE-Sephadex chromatography. The native and subunit molecular weights of these two homogeneous enzymes were determined by gel-filtration chromatography and SDS-polyacrylamide gel electrophoresis. From this study, it was concluded that the two enzymes are tetrameric and have native molecular weights between 200,000 and 280,000 in both species.