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Studies with Ubiquinone-Depleted Submitochondrial Particles.
- Source :
-
European Journal of Biochemistry . Sep74 Part 2, Vol. 47 Issue 3, p475-482. 8p. - Publication Year :
- 1974
-
Abstract
- 1. The incorporation of small amounts of ubiquinone (Q) into pentane-extracted submitochondrial particles has been studied. A procedure is described which allows nearly quantitative incorporation of as little as 0.2 to 0.3 nmol Q/mg protein, i.e: less than 10 % of the Q present in the lyophilized particles prior to extraction. 2. It is shown that both NADH oxidase and succinate oxidase activities can be restored to 100 % of that in lyophilized particles by incorporation of 6-8 nmol Q/mg protein. The relative activities of both oxidases show a parallel response to an increase of the Q content of the particles between 0.2 and 22 nmol Q/mg protein, 50% reactivation being obtained at about 2 nmol Q/mg protein. 3. 50 to 60% of the incorporated Q can be reduced by NADH or succinate, independent of the total concentration of Q in the membrane. Similar reduction values were obtained for lyophilized particles prior to extraction, suggesting that incorporated Q functions similarly to that originally present in the particles. 4. Succinate dehydrogenase activity, which is decreased % by extraction of Q. can be completely restored upon incorporation of only 1.5 nmol Q/mg protein. 5. Extraction of lyophilized particles with pentane + 10% acetone results in a more effective removal of Q, but also in a differential Q requirement for NADH oxidase and succinate oxidase. Thin-layer chromatography shows that extraction with pentane + acetone removes an additional, unidentified, nonpolar lipid. 6. The present data do not support the belief that succinate oxidase and NADH oxidase communicate with separate pools of Q. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00142956
- Volume :
- 47
- Issue :
- 3
- Database :
- Academic Search Index
- Journal :
- European Journal of Biochemistry
- Publication Type :
- Academic Journal
- Accession number :
- 12908534
- Full Text :
- https://doi.org/10.1111/j.1432-1033.1974.tb03715.x