title: Charge translocation by mitochondrial NADH:ubiquinone oxidoreductase (complex I) from Yarrowia lipolytica measured on solid-supported membranes.
abstract: The charge translocation by purified reconstituted mitochondrial complex I from the obligate aerobic yeast Yarrowia lipolytica was investigated after adsorption of proteoliposomes to solid-supported membranes. In presence of n-decylubiquinone (DBQ), pulses of NADH provided by rapid solution exchange induced charge transfer reflecting steady-state pumping activity of the reconstituted enzyme. The signal amplitude increased with time, indicating 'deactive→active' transition of the Yarrowia complex I. Furthermore, an increase of the membrane-conductivity after addition of 5-(N-ethyl-N-isopropyl)amiloride (EIPA) was detected which questiones the use of EIPA as an inhibitor of the Na+/H+-antiporter-like subunits of complex I. This investigation shows that electrical measurements on solid-supported membranes are a suitable method to analyze transport events and 'active/deactive' transition of mitochondrial complex I.
authors.affiliation: Molecular Bioenergetics Group, Medical School, Johann Wolfgang Goethe-University, 60590, Frankfurt am Main, Germany; Goethe University Frankfurt, Institute of Organic Chemistry and Chemical Biology, Buchmann Institute for Molecular Life Sciences, Protein Reaction Control Group, Max-von-Laue-Str. 15, 60438, Frankfurt am Main, Germany.
authors.forename: Ilka
authors.initials: I
authors.lastname: Siebels
authors.affiliation: Molecular Bioenergetics Group, Medical School, Johann Wolfgang Goethe-University, 60590, Frankfurt am Main, Germany; Department of Anesthesiology, Intensive-Care Medicine and Pain Therapy, University Hospital Frankfurt, 60590, Frankfurt am Main, Germany. Electronic address: stefan.droese@kgu.de.
authors.forename: Stefan
authors.initials: S
authors.lastname: Dröse
mesh_terms: D000327:Adsorption; D042967:Electron Transport Complex I / Q000737:chemistry*; D055724:Electrophysiological Phenomena; D005656:Fungal Proteins / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry; D008567:Membranes, Artificial; D008928:Mitochondria / Q000201:enzymology; D009243:NAD / Q000737:chemistry; D018384:Oxidative Stress; D010100:Oxygen / Q000737:chemistry; D011510:Proteolipids / Q000737:chemistry; D014451:Ubiquinone / Q000031:analogs & derivatives / Q000737:chemistry; D025062:Yarrowia / Q000201:enzymology*; D015032:Zinc / Q000737:chemistry
chemical_list: D005656:Fungal Proteins; D008081:Liposomes; D008567:Membranes, Artificial; D011510:Proteolipids; C020485:proteoliposomes; D009243:NAD; D014451:Ubiquinone; C060262:2,3-dimethoxy-5-methyl-6-decyl-1,4-benzoquinone; D042967:Electron Transport Complex I; D015032:Zinc; D010100:Oxygen
keywords: Charge translocation; Complex I; EIPA; Proton pumping; Solid-supported membranes; ‘Active/deactive’ transition