O18 and P32 Exchange Reactions of Mitochondria in Relation to Oxidative Phosphorylation

Oxidative Phosphorylation in in Vitro Aged Mitochondria. I. Factors Controlling the Loss of the Dinitrophenol-Stimulated Adenosine Triphosphatase Activity and Respiratory Control in Mouse Liver Mitochondria*

“…In most instances the inactivation proceeds without any lag period suggesting that traces of endogenous substrates and cofactors provide no protection. A similar timecourse loss has been reported for the ATP-P¡ exchange activity and for phosphorylation (Cross et al, 1949;Boyer et al, 1956;Polis and Shmukler, 1957;Helinski and Cooper, 1960). Paralleling this loss, was a small but definite activation of the endogenous ATPase The effect of albumin on oxidative phosphorylation of aging mouse liver mitochondria.…”

“…During aging, phospholipids decrease and free long-chain fatty acids accumulate stoichiometrically suggesting the involvement of phospholipase A. Albumin does not inhibit the loss of phospholipids but it does "trap" the fatty acids suggesting that loss of function of aged mitochondria is related primarily to the accumulation of fatty acids. These results also suggest that inhibition by phos-T A he loss of capacity for oxidative phosphorylation by in vitro aged mitochondria and submitochondrial particles has been observed on numerous occasions (Hunter and Hixon, 1949; Kielley and Kielley, 1951; Kielley, 1952;Cleland, 1952, 1953;Cross et al, 1949;Ernster, 1956;Boyer et al, 1956; Lester and Hatefi, 1958;Azzone et al, 1960;Helinski and Cooper, 1960;Rossi et al, 1964). The mechanisms underlying this loss of function have not been clearly delineated.…”

Effect of sodium and potassium ions on mitochondrial oxidative phosphorylation. Studies with arsenate

“…The effect of arsenate on the 32P-ATP exchange reaction of mitochondria (Boyer et al, 1954;Boyer et al, 1956) incubated with EDTA and Na+ or K+ was also studied. No significant or reproducible differences in the amount of phosphate incorporated into ATP in 5-min incubation (approximately figure 2: The arsenate-stimulated ATPase activity at various mitochondrial concentrations.…”

Uncoupling of Oxidative Phosphorylation by Carbonyl Cyanide Phenylhydrazones. II. Effects of Carbonyl Cyanide m-Chlorophenylhydrazone on Mitochondrial Respiration

“…With these considerations in mind, a study of the effects of m-Cl-CCP on mitochondrial respiration and respiratory control has been conducted and is reported here. In addition to studies of CCP effects on respiration, it was felt that useful information might be obtained by a study of the ATP-P¡32 exchange reaction described by Boyer et. al.…”