Sodium nitroprusside: mechanism of NO release mediated by sulfhydryl-containing molecules.
Sodium nitroprusside (SNP) is among the most widely studied nitric oxide donors, and its capability of producing NO seems to depend on its interaction with sulfhydryl-containing molecules present in vivo. The aim of this research has been the study of the mechanism of interaction between SNP and sulfhydryl-containing compounds, such as cysteine and glutathione, through detection by EPR, UV-vis, and IR spectroscopy of both the radical and nonradical species involved. An electron-transfer process can be invoked as the key step, which leads to the formation of the reduced SNP radical, the main detectable radical intermediate, and the corresponding S-nitrosothiol, the ending product of NO that can be considered the real storage and transporters of NO. When cysteine was used, a second radical species (A) is detectable: it can be accounted for by the interaction of a byproduct with unreacted cysteine.
Grossi
Loris
L
Dipartimento di Chimica Organica "A. Mangini", Università di Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy.
D'Angelo
Sandra
S
D002021:Buffers; D004578:Electron Spin Resonance Spectroscopy; D006863:Hydrogen-Ion Concentration; D009569:Nitric Oxide / Q000737:chemistry*; D020030:Nitric Oxide Donors / Q000737:chemistry*; D009599:Nitroprusside / Q000737:chemistry*; D010710:Phosphates; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D014867:Water
D002021:Buffers; D020030:Nitric Oxide Donors; D010710:Phosphates; D014867:Water; D009599:Nitroprusside; D009569:Nitric Oxide