The ND2 subunit is labeled by a photoaffinity analogue of asimicin, a potent complex I inhibitor.
NADH:ubiquinone oxidoreductase (complex I) is the entry enzyme of mitochondrial oxidative phosphorylation. To obtain the structural information on inhibitor/quinone binding sites, we synthesized [3H]benzophenone-asimicin ([3H]BPA), a photoaffinity analogue of asimicin, which belongs to the acetogenin family known as the most potent complex I inhibitor. We found that [3H]BPA was photo-crosslinked to ND2, ND1 and ND5 subunits, by the three dimensional separation (blue-native/doubled SDS-PAGE) of [3H]BPA-treated bovine heart submitochondrial particles. The cross-linking was blocked by rotenone. This is the first finding that ND2 was photo-crosslinked with a potent complex I inhibitor, suggesting its involvement in the inhibitor/quinone-binding.
Nakamaru-Ogiso
Eiko
E
Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA. eikoo@mail.med.upenn.edu
Han
Hongna
H
Matsuno-Yagi
Akemi
A
Keinan
Ehud
E
Sinha
Subhash C
SC
Yagi
Takao
T
Ohnishi
Tomoko
T
D000818:Animals; D001577:Benzophenones / Q000737:chemistry*; D002417:Cattle; D042967:Electron Transport Complex I / Q000037:antagonists & inhibitors* / Q000737:chemistry* / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000138:chemical synthesis / Q000737:chemistry*; D005663:Furans / Q000737:chemistry*; D015151:Immunoblotting; D009097:Multienzyme Complexes / Q000378:metabolism; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D021122:Protein Subunits; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D001577:Benzophenones; D004791:Enzyme Inhibitors; D005663:Furans; D009097:Multienzyme Complexes; D021122:Protein Subunits; C061022:bullatacin; C047723:benzophenone; C023107:NADH oxidase; D009247:NADH, NADPH Oxidoreductases; D042967:Electron Transport Complex I