The reaction of the fluorochrome, 8-anilino-1-naphthalene-sulfonic acid (ANS), with fragmented membranes from beef heart mitochondria has been studied. ANS fluorescence is found to be enhanced 25-fold on binding to the membrane fragments in the absence of energy conservation, and this enhancement is increased to 35-fold in the membrane energized by substrate plux oxygen. The fluorescence of bound ANS depends upon the energy state of the membrane fragments, as indicated by the effects of ATP, substrates of the respiratory chain, oligomycin, and uncouplers. It is concluded that the changes of ANS fluorescence indicate structural changes of the mitochondrial membrane associated with energy conservation. The time course of energization is readily followed by ANS, and has a half-time of two seconds at 26 degrees .

Adenosine Triphosphate↗

PubMed1969

Energy and Electron Transfer Systems of Chlamydomonas reinhardi. I. Photosynthetic and Respiratory Cytochrome Systems of the Pale Green Mutant.

The role of cytochromes in photosynthetic electron transfer system has been studied using the pale green mutant of Chlamydomonas reinhardi (ATCC 18302). The existence of cytochromes b(563) and f is confirmed, while no significant amount of ascorbate-reducible cytochrome b(559) is detected in this mutant. The presence of cytochrome c and a small amount of a-type cytochrome is determined in these cells.Light-induced oxidation of cytochrome b(563) is eliminated by oxygen-induced oxidation, and oxygen-induced oxidation is greatly diminished under illumination. Antimycin A diminishes the oxygen-induced oxidation of cytochrome b(563), but does not affect light-induced oxidation. In the aerobic state in the presence of 2-heptyl-4-hydroxyquinoline-N-oxide, cytochrome b(563) is reduced by illumination with far red light; this reduction is not inhibited by 3-(4'-chlorophenyl)-1,1-dimethylurea.A tentative scheme for the electron transfer system in chloroplasts, which involves a cyclic pathway via cytochrome b(563) and its interaction with oxygen, is proposed.

Journal Article↗

PubMed1969

Studies of the energy-transfer system of submitochondrial particles. Kinetic studies of the effect of oligomycin on the respiratory chain of EDTA particles.

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Alcohol Oxidoreductases↗

PubMed1968

Activation of malate-linked reductions of NAD and flavoproteins in Ascaris muscle mitochondria by phosphate.

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Animals↗