title: Oxidative phosphorylation enzyme complexes in caloric restriction.
abstract: Free radicals, generated especially by electron leakage from mitochondrial electron transport chain (ETC), are accepted as one of the possible causes of aging. Long-term caloric restriction (CR) is known to increase the species specific average and maximum life spans. Thus it provides a means for investigating mechanisms of aging. There is evidence suggesting a decrease in the free radical production with CR. In this study, Blue-Native PAGE (BN-PAGE) technique was used to investigate the effect of CR on the oxidative phosphorylation enzyme complexes. Of the total 30 female Swiss Albino balb/c mice, 15 were used as control and the other 15 as CR group. Alternate day feeding regimen was used in the CR group for 66 weeks beginning at the end of 3rd month. In the control group, 5 (33.3%) mice died, 3 (20%) of them of breast cancer, 2 (13.3%) of unknown causes and no death cases were observed in the CR group during the study. BN-PAGE was performed on the extracts from brain mitochondrial fractions. Complexes II and V were excluded from the study due to some analytical limitations. No difference was found in the levels of complexes I and III between the groups. In the CR group, complex IV level was found increased and the ratio of complex III-IV decreased compared with the control group. Since there is a slight increase (108%) in the level of complex IV in the CR group, our results could suggest possible partial compensation of electron leakage in the upstream complexes in ETC, and the decrease of free radical production with CR.
authors.affiliation: Department of Biochemistry and Clinical Biochemistry, Gülhane School of Medicine, Etlik-06018, Ankara, Turkey. aolgun@yahoo.com
authors.forename: Abdullah
authors.initials: A
authors.lastname: Olgun
authors.forename: Serif
authors.initials: S
authors.lastname: Akman
authors.forename: Muhittin A
authors.initials: MA
authors.lastname: Serdar
authors.forename: Turker
authors.initials: T
authors.lastname: Kutluay
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000375:Aging / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000378:metabolism; D002352:Carrier Proteins; D004579:Electron Transport; D042967:Electron Transport Complex I; D042963:Electron Transport Complex II; D014450:Electron Transport Complex III / Q000378:metabolism; D003576:Electron Transport Complex IV / Q000378:metabolism; D002149:Energy Intake; D005260:Female; D005609:Free Radicals / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008928:Mitochondria / Q000378:metabolism; D025261:Mitochondrial Proton-Translocating ATPases; D008954:Models, Biological; D009097:Multienzyme Complexes / Q000378:metabolism; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D010085:Oxidative Phosphorylation; D010088:Oxidoreductases / Q000378:metabolism; D013385:Succinate Dehydrogenase / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D005609:Free Radicals; D008565:Membrane Proteins; D009097:Multienzyme Complexes; D010088:Oxidoreductases; D042963:Electron Transport Complex II; D013385:Succinate Dehydrogenase; D009247:NADH, NADPH Oxidoreductases; D003576:Electron Transport Complex IV; D000251:Adenosine Triphosphatases; D025261:Mitochondrial Proton-Translocating ATPases; D042967:Electron Transport Complex I; D014450:Electron Transport Complex III; C020439:oligomycin sensitivity-conferring protein