Age‐Related Changes of Mitochondrial F0F1 ATP Synthase a

Evidence indicates that the contribution of mitochondrial oxidative phosphorylation to the energy demand of eukaryotic cells changes during development and aging.'-' Changes in the activity and content of respiratory enzymes have been described in the course of prenatal and neonatal de~elopment .~-~ An aging-related decrease in the activity of respiratory enzymes was observed in mammalian tis~ue.~f' This seems to be associated with alterations in mitochondrial DNA, deletions and mutations that accumulate with age, and depressed expression of certain subunits of respiratory comple~es .~ .~ We focused our attention on age-related changes in the FoFl H+-ATP synthase of mitochondria, the key enzyme of oxidative phosphorylation which uses the energy, made available as transmembrane protonmotive force by the three complexes of the respiratory chain, to phosphorylate ADP to ATP.Io The ATP synthase complex of mitochondria is a multipeptide complex*O.ll of the inner membrane composed by two oligomeric moieties, F1 and Fo, which are responsible for chemical catalysis and proton conduction, respectively.I0 Of the 13 polypeptides of the mammalian FoF, ATP synthase, 11 are encoded by nuclear and 2 by mitochondrial genes." The results of our studies show that the content and functional activities of the ATP synthase complex change dramatically in various tissues of the rat in the course of aging and in rat liver during regeneration.