S-NO-actin: S-nitrosylation kinetics and the effect on isolated vascular smooth muscle
- Cite this article as:
- Dalle-donne, I., Milzani/snm>, A., Giustarini, D. et al. J Muscle Res Cell Motil (2000) 21: 171. doi:10.1023/A:1005671319604
- 109 Downloads
We describe the modification of reactive actin sulfhydryls by S-nitrosoglutathione. Kinetics of S-nitrosylation and denitrosylation suggest that only one cysteine of actin is involved in the reactions. By using the bifunctional sulfhydryl cross-linking reagent N,N′-1,4-phenylenebismaleimide and the monofunctional reagent N-iodoacetyl-N′-(5-sulpho-1-naphthyl)ethylenediamine, we identified this residue as Cys374. The time course of filament formation followed by high-shear viscosity changes revealed that S-nitrosylated G-actin polymerizes less efficiently than native monomers. The observed decrease in specific viscosity at steady state is due mainly to a marked inhibition of filament end-to-end annealing and, partially, to a reduction in F-actin concentration. Finally, S-nitrosylated actin acts as nitric oxide donor showing a fast, potent vasodilating activity at unusually low concentrations, being comparable with that of low molecular weight nitrosothiols.