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Maesaquinone: A Novel Inhibitor of Plant Mitochondrial Respiratory Enzymes That React with Ubiquinone
Author(s) -
Affourtit Charles,
Whitehouse David G.,
Moore Anthony L.
Publication year - 2000
Publication title -
iubmb life
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.132
H-Index - 113
eISSN - 1521-6551
pISSN - 1521-6543
DOI - 10.1080/15216540050167089
Subject(s) - alternative oxidase , cytochrome c oxidase , mitochondrion , succinate dehydrogenase , nadh dehydrogenase , biochemistry , enzyme , coenzyme q – cytochrome c reductase , dehydrogenase , respiratory chain , chemistry , respiration , biology , oxidase test , cytochrome , stereochemistry , cytochrome c , protein subunit , botany , gene
The effect of maesaquinone, 2‐(14‐nonadecenyl)‐3,6‐dihydroxy5‐methyl‐1,4‐benzoquinone, on plant mitochondrial respiration has been investigated. In mitochondria isolated from thermogenic Arum maculatum spadices, this compound inhibits both cytochrome and alternative pathway activities. Kinetic analyses reveal that this inhibition is the result of potent effects of maesaquinone on the alternative oxidase (ID50 <0.3θM) and complex III (ID50 <5θM). Succinate dehydrogenase and external NADH dehydrogenase are also inhibited, albeit to a lesser extent (∼30% at 1 θM). These data suggest that maesaquinone specifically affects the interaction of the respective enzymes with ubiquinone.