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FMN site‐independent energy‐linked reverse electron transfer in mitochondrial respiratory complex I
Author(s) -
Gladyshev Grigory V.,
Grivennikova Vera G.,
Vinogradov Andrei D.
Publication year - 2018
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1002/1873-3468.13117
Subject(s) - ubiquinol , flavin mononucleotide , chemistry , electron transfer , nad+ kinase , electron transport chain , ferricyanide , flavin group , respiratory chain , substrate (aquarium) , redox , electron acceptor , stereochemistry , photochemistry , biochemistry , enzyme , coenzyme q – cytochrome c reductase , mitochondrion , cytochrome c , biology , inorganic chemistry , ecology
A simple assay procedure for measuring ATP ‐dependent reverse electron transfer from ubiquinol to hexaammineruthenium (III) ( HAR ) catalyzed by mitochondrial respiratory complex I is introduced. The specific activity of the enzyme in this reaction and its sensitivity to the standard inhibitors and uncoupling are the same as with other well‐known electron acceptors, NAD + and ferricyanide. In contrast to the reactions with these acceptors, the energy‐dependent HAR reduction is not inhibited by NADH ‐ OH , the specific inhibitor of NADH ‐binding site. These results suggest that a catalytically competent electron connection exists between HAR and a redox component of complex I that is different from flavin mononucleotide bound at the substrate‐binding site.