Oxidative activity of cytoplasmic particles of apples: Krebs cycle oxidations, oxidative phosphorylation, & cytochromes

Oxidative phosphorylation catalyzed by cytoplasmic particles isolated from malignant tissues.

Malonate inhibition of oxidations in the Krebs tricarboxylic acid cycle.

The inhibition of succinate oxidation by malonate is a well known phenomenon. Since the oxidation of succinate to fumarate is an integral part of the Krebs cycle of oxidations, it has been generally assumed that the inhibitory effect of malonate upon the oxidation of any member of the cycle is the result of the inhibition of the succinate to fumarate step. However, the present paper provides ev...

Interaction of fluorescent probes with submitochondrial particles during oxidative phosphorylation.

Addition of several N-arylaminonaphthalenesulfonate dyes to submitochondrial particles from bovine heart resulted in an enhancement of fluorescence of from SOto 150-fold and a considerable shift in the wave length of maximum emission toward the ultraviolet. The results indicate 40 to 55 dyebinding sites per mg of submitochondrial particles. A preliminary search revealed that mitochondrial ATPas...

Uncouplers of oxidative phosphorylation.

Uncouplers of oxidative phosphorylation in mitochondria inhibit the coupling between the electron transport and phosphorylation reactions and thus inhibit ATP synthesis without affecting the respiratory chain and ATP synthase (H(+)-ATPase). Miscellaneous compounds are known to be uncouplers, but weakly acidic uncouplers are representative because they show very potent activities. The most poten...

Uncouplers of Oxidative Phosphorylation

was proportional to the acidity of the imidazole -NH group. Tetrachloro-2trifluoromethylbenzimidazole was the most active (50% uncoupling of oxidative phosphorylation at 7-9 x 10-8M, pK5.04). Nitro-substituted analogues were less active than predicted from pK considerations or from partition-coefficient measurements. 3. Introduction of an -NH2 or -CO2H substituent caused a loss of uncoupling ac...