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Biomedical subjects

P L Dutton

Publications and source records attributed to P L Dutton.

At least 145 records · Page 8Linked to original sources
PubMed1972

Aerobic reduction of cytochrome b 566 in pigeon-heart mitochondria (succinate-cytochrome C1 reductase-stopped-flow kinetics).

In anaerobic, uncoupled pigeon-heart mitochondria treated with oxidizable substrate, the cytochrome b(566) remains largely oxidized. In the presence of antimycin A, addition of oxygen induces a reduction of this cytochrome. The rate of cytochrome b(566) reduction is comparable to and dependent on the rate of cytochrome c(1) oxidation. Kinetic data suggest that either ubiquinone or another donor of similar potential provides electrons for the reduction of cytochrome b(566). It is postulated that the aerobic reduction of cytochrome b(566) is directly related to the energy conservation at site II.

Aerobiosis↗
PubMed1971

The Respiratory Chain of Plant Mitochondria: IX. Oxidation-Reduction Potentials of the Cytochromes of Mung Bean Mitochondria.

The oxidation-reduction potentials of the cytochromes of the respiratory chain of mung bean (Phaseolus aureus) mitochondria have been measured under strictly anaerobic conditions with a combined spectrophotometric/potentiometric method. The midpoint potentials at pH 7.2 are as follows: cytochrome a: +190 millivolts; a(3): +380 millivolts; b(553): +75 millivolts; b(557): +42 millivolts; b(562): -77 millivolts; c(547) and c(549): +235 millivolts. (The subscripts refer to the difference absorbance maxima observed for these cytochromes in reduced-minus-oxidized difference spectra recorded at 77 K.) The same values of midpoint potentials at pH 7.2 are obtained with mitochondria depleted of energy by aerobic incubation with ADP and uncoupler in the presence of inorganic phosphate, or with coupled mitochondria energized with ATP in the absence of inorganic phosphate. Coupling site II is placed between b(553)/b(557) and c(549)/c(547) in these mitochondria, and coupling site III is placed between a and a(3).

Journal Article↗