Mechanism of nitric oxide release from S-nitrosothiols. J Biol Chem 1996 Aug 02;271(31):18596-603
Date
08/02/1996Pubmed ID
8702510DOI
10.1074/jbc.271.31.18596Scopus ID
2-s2.0-0029780524 (requires institutional sign-in at Scopus site) 530 CitationsAbstract
S-Nitrosothiols have many biological activities and have been suggested to be intermediates in signal transduction. The mechanism and products of S-nitrosothiol decomposition are of great significance to the understanding of nitric oxide (.NO) biochemistry. S-Nitrosothiols are stable compounds at 37 degrees C and pH 7.4 in the presence of transition metal ion chelators. The presence of trace transition metal ions (present in all buffers) stimulates the catalytic breakdown of S-nitrosothiols to .NO and disulfide. Thiyl radicals are not formed as intermediates in this process. Photolysis of S-nitrosothiols results in the formation of .NO and disulfide via the intermediacy of thiyl radicals. Reduced metal ion (e.g. Cu+) decomposes S-nitrosothiols more rapidly than oxidized metal ion (e.g. Cu2+) indicating that reducing agents such as glutathione and ascorbate can stimulate decomposition of S-nitrosothiol by chemical reduction of contaminating transition metal ions. Transnitrosation can also stimulate S-nitrosothiol decomposition if the product S-nitrosothiol is more susceptible to transition metal ion-catalyzed decomposition than the parent S-nitrosothiol. Equilibrium constants for the transnitrosation reactions of reduced glutathione, either with S-nitroso-N-acetyl-dl-penicillamine or with S-nitroso-L-cysteine indicate that S-nitrosoglutathione formation is favored. The biological relevance of S-nitrosothiol decomposition is discussed.
Author List
Singh RJ, Hogg N, Joseph J, Kalyanaraman BAuthors
Neil Hogg PhD Associate Dean, Professor in the Biophysics department at Medical College of WisconsinBalaraman Kalyanaraman PhD Professor in the Biophysics department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
Cyclic N-OxidesElectron Spin Resonance Spectroscopy
Free Radicals
Glutathione
Glutathione Disulfide
Kinetics
Mercaptoethanol
Molecular Structure
Nitric Oxide
Nitroso Compounds
Penicillamine
Photolysis
S-Nitroso-N-Acetylpenicillamine
S-Nitrosoglutathione
S-Nitrosothiols
Spin Labels
Sulfhydryl Compounds
