title: The interaction of rubroskyrin, a modified bis-anthraquinone pigment fromPenicillium islandicum Sopp, with respiratory chain of liver mitochondria.
abstract: Rubroskyrin, a modified bisanthraquinone pigment from an yellow rice moldPenicillium islandicum Sopp, was examined for its redox-interaction with the mitochondrial respiratory chain by using rat liver submitochondrial particles (SMP) and was compared with luteoskyrin and rugulosin.Rubroskyrin showed a redox interaction with the NAD-linked respiratory chain of SMP, promoting NADH oxidase in the presence of rotenone, a specific inhibitor to coupling site I of the respiratory chain. Rubroskyrin-mediated NADH oxidase was not inhibited by antimycin A and cyanide, inhibitors to coupling sites II and III, respectively, indicating a generation of an electron transport shunt from a rotenone-insensitive site of NADH dehydrogenase (complex I) to dissolved oxygen. An electrontransport shunt to cytochromec oxidase from complex I was also observed in the experiment with cytochromec and antimycin A. Rubroskyrin did not interact with succinate-linked respiratory chain.Such enzymatic redox response which generates electron transport shunt was not detected for luteoskyrin and rugulosin in the present study.
authors.affiliation: Department of Biochemistry, Gifu University School of Medicine, Tsukasa-cho 40, Gifu 500, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Mori
authors.forename: K
authors.initials: K
authors.lastname: Kawai
authors.forename: Y
authors.initials: Y
authors.lastname: Nozawa
authors.forename: Y
authors.initials: Y
authors.lastname: Ogihara