Mitochondrial respirasome works as a single unit and the cross-talk between complexes I, III2 and IV stimulates NADH dehydrogenase activity
| Autor: | Meztli Reyes-Galindo, Oscar Flores-Herrera, Mercedes Esparza-Perusquía, Federico Martínez, Roselia Suarez, Jaime de Lira-Sánchez, J. Pablo Pardo |
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| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
chemistry.chemical_classification 030102 biochemistry & molecular biology biology Protein subunit Cytochrome c Biophysics Cell Biology Antimycin A Oxidative phosphorylation Mitochondrion Biochemistry NADH dehydrogenase activity 03 medical and health sciences chemistry.chemical_compound 030104 developmental biology chemistry Oxidoreductase Respirasome biology.protein |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Bioenergetics. 1860:618-627 |
| ISSN: | 0005-2728 |
| DOI: | 10.1016/j.bbabio.2019.06.017 |
| Popis: | Ustilago maydis is an aerobic basidiomycete that depends on oxidative phosphorylation for its ATP supply, pointing to the mitochondrion as a key player in its energy metabolism. Mitochondrial respiratory complexes I, III2, and IV occur in supramolecular structures named respirasome. In this work, we characterized the subunit composition and the kinetics of NADH:Q oxidoreductase activity of the digitonine-solubilized respirasome (1600 kDa) and the free-complex I (990 kDa). In the presence of 2,6-dimethoxy-1,4-benzoquinone (DBQ) and cytochrome c, both the respirasome NADH:O2 and the NADH:DBQ oxidoreductase activities were inhibited by rotenone, antimycin A or cyanide. A value of 2.4 for the NADH oxidized/oxygen reduced ratio was determined for the respirasome activity, while ROS production was less than 0.001% of the oxygen consumption rate. Analysis of the NADH:DBQ oxidoreductase activity showed that respirasome was 3-times more active and showed higher affinity than free-complex I. The results suggest that the contacts between complexes I, III2 and IV in the respirasome increase the catalytic efficiency of complex I and regulate its activity to prevent ROS production. |
| Databáze: | OpenAIRE |
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