Two binding sites of inhibitors in NADH: ubiquinone oxidoreductase (complex I). Relationship of one site with the ubiquinone-binding site of bacterial glucose:ubiquinone oxidoreductase.


Friedrich, T; van Heek, P; Leif, H; Ohnishi, T; Forche, E; Kunze, B; Jansen, R; Trowitzsch-Kienast, W; Höfle, G; Reichenbach, H

Publication Year 1994
Journal European Journal of Biochemistry / FEBS
Pages 691-698
Volume 219
Issue 1-2
PMID 8307034.0
DOI 10.1111/j.1432-1033.1994.tb19985.x

The effect of ten naturally occurring and two synthetic inhibitors of NADH:ubiquinone oxidoreductase (complex I) of bovine heart, Neurospora crassa and Escherichia coli and glucose:ubiquinone oxidoreductase (glucose dehydrogenase) of Gluconobacter oxidans was investigated. These inhibitors could be divided into two classes with regard to their specificity and mode of action. Class I inhibitors, including the naturally occurring piericidin A, annonin VI, phenalamid A2, aurachins A and B, thiangazole and the synthetic fenpyroximate, inhibit complex I from all three species in a partially competitive manner and glucose dehydrogenase in a competitive manner, both with regard to ubiquinone. Class II inhibitors including the naturally occurring rotenone, phenoxan, aureothin and the synthetic benzimidazole inhibit complex I from all species in an non-competitive manner, but have no effect on the glucose dehydrogenase. Myxalamid PI could not be classified as above because it inhibits only the mitochondrial complex I and in a competitive manner. All inhibitors affect the electron-transfer step from the high-potential iron-sulphur cluster to ubiquinone. Class I inhibitors appear to act directly at the ubiquinone-catalytic site which is related in complex I and glucose dehydrogenase.