S-NO-actin: S-nitrosylation kinetics and the effect on isolated vascular smooth muscle

J Muscle Res Cell Motil. 2000 Feb;21(2):171-81. doi: 10.1023/a:1005671319604.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism*
  • Actins / pharmacology
  • Animals
  • Cross-Linking Reagents / pharmacology
  • Glutathione / analogs & derivatives*
  • Glutathione / metabolism
  • Glutathione / pharmacology
  • Muscle, Smooth, Vascular / drug effects
  • Muscle, Smooth, Vascular / metabolism*
  • Nitric Oxide Donors / metabolism*
  • Nitric Oxide Donors / pharmacology
  • Nitro Compounds / metabolism*
  • Nitro Compounds / pharmacology
  • Rabbits


  • Actins
  • Cross-Linking Reagents
  • Nitric Oxide Donors
  • Nitro Compounds
  • S-nitroglutathione
  • Glutathione