Complexes DNICs

DNICs are relatively stable and can be stored at —80°C for weeks without much loss of NO [155], however, their stabilities decrease dramatically at room temperature to render unbound NO. NO bound to thiols may account for the low yield of free NO sometimes detected in solutions involving DNICs in the presence of high concentrations of thiols [126]. The decomposition is acid catalyzed to free NO and S-nitrosothiol (RSNO). Of course, protein-bound DNICs are more stable and serve as potential sinks for low molecular weight DNICs. 

DNICs continue to be a relevant aspect of nitric oxide research and indicate the high affinity of NO for metal centers, especially ferrous ions, when compared with sulfur bound NO complexes, such as S-nitrosothiols. 

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Lu TT, Chiou SJ et al (2006) Mononitrosyl tris(thiolate) iron complex [Fe(NO) (SPh)3] and dinitrosyl irrai ctnnplex [(EtS)2Fe(NO)2] formation pathway of dinitrosyl iron complexes (DNICs) frmn nibosylatirai of biomimetic rubredoxin [Fe(SR)4] (R = Ph, Et). Inorg Chem 45 8799-8806... 

Tsai FT, Chiou SJ et al (2005) Dinitrosyl iron complexes (DNICs) [L2Fe(NO)2]- (L = Thiolate) interconversion among Fe (NO)2 DNICs, Fe(NO)2 DNICs, and [2Fe-2S] clusters, and the critical role of the thiolate ligands in regulating NO release of DNICs. Inorg Chem 44 5872-5881... 

Hung MC, Tsai MC et al (2006) Transformation and structural discrimination between the neutral Fe(NO)2 dinitrosyliron complexes (DNICs) and the anionic/cationic Fe(NO)2 DNICs. Inorg Chem 45 6041-6047... 

Lu TT, Lai SH et al (2011) Discrimination of mononuclear and dinuclear dinitrosyl iron complexes (DNICs) by S K-edge X-ray absorption spectroscopy insight into the electronic structure and reactivity of DNICs. Inorg Chem 50 5396-5406... 

Tsai ML, Hsieh CH, Liaw WF (2007) Dinitrosyl iron complexes (DNICs) containing S/N/0 ligation transformation of Roussin s red ester into the neutral Fe(NO)2 DNICs. Inorg Chem 46 5110-5117... 

Lu TT, Huang HW, Liaw WF (2009) Anionic mixed thiolate-sulfide-bridged Roussin s red esters [(NO)2Fe(p-SR)(p-S)Fe(NO)2] (R = Et, Me, Ph) a key intermediate for transformation of dinitrosyl iron complexes (DNICs) to [2Fe-2S] clusters. Inorg Chem 48 9027-9035... 

Tsai ML, Liaw WF (2006) Neutral Fe(NO)2 dinitrosyliron complex (DNIC)[ (SCgH4-o-NHCOPh)(Im)Fe(NO)2] (Im = Imidazole) interconversion among the anionic/neutral Fe(NO)2 DNICs and Roussin s red ester. Inorg Chem 45 6583-6585... 

Brothers SM, Darensbourg MY, Hall MB (2011) Modeling structures and vibrational frequencies for dinitrosyl iron complexes (DNICs) with density functional theory. Inorg Chem 50 8532-8540... 

Nitric oxide (NO) has a key role in many bioregulatory systems, including immune stimulation, platelet inhibition, neurotransmission, and relaxation of smooth muscle [1]. Its biosynthesis derives from nitric oxide synthases which catalyse the conversion of L-arginine to L-citrulline, resulting in NO release. Among the proposed NO storage components are protein-bound thionitrosyls and protein-bound dinitrosyl iron complexes (DNIC) [2,3]. The latter are derived from iron-sulphur... 

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