Inhibition of the alternative oxidase stimulates H2O2 production in plant mitochondria

• Published in: FEBS letters Vol. 415; no. 1; pp. 87 - 90
• Main Authors: Popov, V.N, Simonian, R.A, Skulachev, V.P, Starkov, A.A
• Format: Journal Article
• Language: English
• Published: England 22-09-1997
• Subjects: 2′,7′-dichlorodihydrofluorescein diacetate; Alternative oxidase; Animals; Antioxidants; Antioxygen defence; Cell Respiration - drug effects; Enzyme Inhibitors - pharmacology; Glycine max - enzymology; H2DCF-DA; H2O2; Hydrogen Peroxide - metabolism; Mitochondria - enzymology; Mitochondria, Liver - drug effects; Mitochondria, Liver - enzymology; Mitochondrial Proteins; Oxidoreductases - antagonists & inhibitors; Pisum sativum - enzymology; Plant mitochondrion; Plant Proteins; Potassium Cyanide - pharmacology; Propyl Gallate - pharmacology; Rats; Reactive oxygen species; Reactive Oxygen Species - metabolism; ROS; salicyl hydroxamate; Salicylamides - pharmacology; SHAM; Succinic Acid - metabolism
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/S0014-5793(97)01099-5

The hypothesis that a non‐coupled alternative oxidase of plant mitochondria operates as an antioxygen defence mechanism [Purvis, A.C. and Shewfelt, R.L., Physiol. Plant. 88 (1993) 712–718; Skulachev, V.P., Biochemistry (Moscow) 59 (1994) 1433–1434] has been confirmed in experiments on isolated soybean and pea cotyledon mitochondria. It is shown that inhibitors of the alternative oxidase, salicyl hydroxamate and propyl gallate strongly stimulate H2O2 production by these mitochondria oxidizing succinate. Effective concentrations of the inhibitors proved to be the same as those decreasing the cyanide‐resistant respiration. The inhibitors proved to be ineffective in stimulating H2O2 formation in rat liver mitochondria lacking the alternative oxidase.