REVIEW: Biochemical Predetermination of the NO Synthase and Nitrite Reductase Components of the Nitric Oxide Cycle

V. P. Reutov

Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, ul. Butlerova 5a, Moscow, 117865 Russia; fax: (095) 338-8500

Received July 17, 1998; Revision received January 16, 1999

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This review presents some aspects of a concept of cellular evolution bearing a relationship to nitrate--nitrite respiration, the endosymbiosis theory, and the origin of NO synthase and nitrite reductase activity in heme-containing proteins. Analysis of structural and functional unity of the NO synthase and nitrite reductase systems suggests that these systems did not arise without any relation to evolutionarily ancient energetic systems of cells. The use of symmetry principles reveals commonalities among many electron transport chains which in the language of physics is called "invariance". This work also comparatively analyzes the nitric oxide cycle and the known nitrogen cycle. The ideas about evolution of the NO synthase and nitrite reductase systems developed here are clearly compatible with the endosymbiotic theory and the hypothesis that nitrate--nitrite respiration was a precursor of oxygen-dependent respiration.

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KEY WORDS: nitric oxide cycle, endosymbiosis theory, concept of nitrate--nitrite respiration, hypoxia

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