title: Mitochondrial glucose-6-phosphate dehydrogenase from Saccharomyces cerevisiae.
abstract: In Saccharomyces cerevisiae, a small proportion of the glucose-6-P dehydrogenase activity is firmly associated with the mitochondrial fraction and is not removed by repeated washing or density-gradient centrifugation. However, the enzyme is released by sonic disruption. Mitochondrial glucose-6-P dehydrogenase that is released by sonication and partially purified has been found to be similar to cytosol glucose-6-P dehydrogenase with respect to electrophoretic mobility, isoelectric point, pH optimum, molecular size, and apparent KM's for NADP+ and glucose-6-P. These results indicate that a single species of glucose-6-P dehydrogenase is synthesized in S. cerevisiae and that the enzyme has more than one intracellular location. Mitochondrial glucose-6-P dehydrogenase may be a source of intramitochondrial NADPH and may function with hexokinase and transhydrogenase to provide a pathway for glucose oxidation that is coupled to the synthesis of mitochondrial ATP. A constant proportion of total glucose-6-P dehydrogenase activity remains compartmented in the mitochondrial fraction throughout the growth cycle.
mesh_terms: D002453:Cell Cycle; D004586:Electrophoresis; D005954:Glucosephosphate Dehydrogenase / Q000302:isolation & purification / Q000378:metabolism*; D005958:Glucosephosphates / Q000378:metabolism; D007526:Isoelectric Point; D007700:Kinetics; D008928:Mitochondria / Q000201:enzymology*; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000378:metabolism*
chemical_list: D005958:Glucosephosphates; D005954:Glucosephosphate Dehydrogenase