title: Does perthionitrite (SSNO(-)) account for sustained bioactivity of NO? A (bio)chemical characterization.
abstract: Hydrogen sulfide (H2S) and nitric oxide (NO) are important signaling molecules that regulate several physiological functions. Understanding the chemistry behind their interplay is important for explaining these functions. The reaction of H2S with S-nitrosothiols to form the smallest S-nitrosothiol, thionitrous acid (HSNO), is one example of physiologically relevant cross-talk between H2S and nitrogen species. Perthionitrite (SSNO(-)) has recently been considered as an important biological source of NO that is far more stable and longer living than HSNO. In order to experimentally address this issue here, we prepared SSNO(-) by two different approaches, which lead to two distinct species: SSNO(-) and dithionitric acid [HON(S)S/HSN(O)S]. (H)S2NO species and their reactivity were studied by (15)N NMR, IR, electron paramagnetic resonance and high-resolution electrospray ionization time-of-flight mass spectrometry, as well as by X-ray structure analysis and cyclic voltammetry. The obtained results pointed toward the inherent instability of SSNO(-) in water solutions. SSNO(-) decomposed readily in the presence of light, water, or acid, with concomitant formation of elemental sulfur and HNO. Furthermore, SSNO(-) reacted with H2S to generate HSNO. Computational studies on (H)SSNO provided additional explanations for its instability. Thus, on the basis of our data, it seems to be less probable that SSNO(-) can serve as a signaling molecule and biological source of NO. SSNO(-) salts could, however, be used as fast generators of HNO in water solutions.
authors.affiliation: Department of Chemistry and Pharmacy, Friedrich-Alexander University of Erlangen-Nuremberg , Egerlandstrasse 1, 91058 Erlangen, Germany.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Wedmann
authors.affiliation: Department of Chemistry and Pharmacy, Friedrich-Alexander University of Erlangen-Nuremberg , Egerlandstrasse 1, 91058 Erlangen, Germany.
authors.forename: Achim
authors.initials: A
authors.lastname: Zahl
authors.affiliation: Department of Chemistry and Pharmacy, Friedrich-Alexander University of Erlangen-Nuremberg , Egerlandstrasse 1, 91058 Erlangen, Germany.
authors.forename: Tatyana E
authors.initials: TE
authors.lastname: Shubina
authors.affiliation: Department of Chemistry and Pharmacy, Friedrich-Alexander University of Erlangen-Nuremberg , Egerlandstrasse 1, 91058 Erlangen, Germany.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Dürr
authors.affiliation: Department of Chemistry and Pharmacy, Friedrich-Alexander University of Erlangen-Nuremberg , Egerlandstrasse 1, 91058 Erlangen, Germany.
authors.forename: Frank W
authors.initials: FW
authors.lastname: Heinemann
authors.affiliation: Department of Chemistry, University of Hamburg , Martin-Luther-King-Platz 6, 20146 Hamburg, Germany.
authors.forename: Bernhard Eberhard Christian
authors.initials: BE
authors.lastname: Bugenhagen
authors.affiliation: Department of Chemistry, University of Hamburg , Martin-Luther-King-Platz 6, 20146 Hamburg, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Burger
authors.affiliation: Department of Chemistry and Pharmacy, Friedrich-Alexander University of Erlangen-Nuremberg , Egerlandstrasse 1, 91058 Erlangen, Germany.
authors.forename: Ivana
authors.initials: I
authors.lastname: Ivanovic-Burmazovic
authors.affiliation: Department of Chemistry and Pharmacy, Friedrich-Alexander University of Erlangen-Nuremberg , Egerlandstrasse 1, 91058 Erlangen, Germany.
authors.forename: Milos R
authors.initials: MR
authors.lastname: Filipovic
mesh_terms: D006862:Hydrogen Sulfide / Q000737:chemistry; D009569:Nitric Oxide / Q000737:chemistry*; D009573:Nitrites / Q000737:chemistry*; D010084:Oxidation-Reduction; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D009573:Nitrites; D013438:Sulfhydryl Compounds; C000606391:perthionitrite; D009569:Nitric Oxide; D006862:Hydrogen Sulfide