REVIEW: Dinitrosyl Iron Complexes and S-Nitrosothiols Are Two Possible Forms for Stabilization and Transport of Nitric Oxide in Biological Systems

A. F. Vanin

Institute of Chemical Physics, Russian Academy of Sciences, ul. Kosygina 4, Moscow, 117977 Russia; fax: (095) 938-2156; E-mail: mikoyan@center.chph.ras.ru

Received February 18, 1998

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The physicochemical properties, mechanisms of synthesis and decomposition of dinitrosyl iron complexes (DNICs) with thiol-containing ligands and of S-nitrosothiols (RS-NO), and the potential role of these compounds in storage and transport of NO in biological systems are reviewed. Special attention is given to the phenomenon of mutual transformation of DNIC and RS-NO catalyzed by Fe²⁺. Each Fe²⁺ binds two neutral NO molecules in the DNICs, catalyzes their mutual oxidation--reduction with formation of nitrous oxide and nitrosonium ions appearing in the DNICs. These ions S-nitrosate thiol-compounds with RS-NO formation. Fe²⁺ binds two RS-NO molecules and catalyzes their mutual oxidation--reduction followed by decomposition of the resulting molecules. Mutual conversion of DNICs and RS-NO regulated by iron, thiol, and NO levels is suggested to provide NO transport in cells and tissues.

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KEY WORDS: nitric oxide, dinitrosyl iron complexes, S-nitrosothiols, cells and tissues

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