6-Phosphogluconate dehydrogenase from Drosophila melanogaster. I. Purification and properties of the A isozyme.
6-Phosphogluconate dehydrogenase is evident at all developmental stages of Drosophila melanogaster. The activity level is highest in early third instar larvae and declines to a lower, but relatively constant, level at all later stages of development. The enzyme is localized in the cytosolic portion of the cell. The A-isozymic form of 6-phosphogluconate dehydrogenase was purified to homogeneity and has a molecular weight of 105,000. The enzyme is a dimer consisting of subunits with molecular weights of 55,000 and 53,000. For the oxidative decarboxylation of 6-phosphogluconate the Km for substrate is 81 muM while that for NADP+ is 22.3 muM. The optimum pH for activity is 7.8 while the optimum temperature is 37 C.
D000818:Animals; D003593:Cytoplasm / Q000201:enzymology; D004331:Drosophila melanogaster / Q000201:enzymology* / Q000254:growth & development; D006863:Hydrogen-Ion Concentration; D007527:Isoenzymes / Q000302:isolation & purification*; D008675:Metamorphosis, Biological; D008970:Molecular Weight; D010734:Phosphogluconate Dehydrogenase / Q000302:isolation & purification*; D013379:Substrate Specificity
D007527:Isoenzymes; D010734:Phosphogluconate Dehydrogenase