Inhibition of NF-kappaB DNA binding by nitric oxide

Nucleic Acids Res. 1996 Jun 15;24(12):2236-42. doi: 10.1093/nar/24.12.2236.


It has been suggested that the NF-kappaB transcription factor family may mediate expression of the gene encoding the cytokine-inducible form of nitric oxide synthase (iNOS). To establish if nitric oxide (NO) could in turn affect activity of NF-kappaB, the ability of NO-donor compounds to influence NF-kappaB DNA binding activity in vitro was investigated. NO-donor compounds sodium nitroprusside (SNP) and S-nitroso-N-acetylpenicillamine (SNAP) both inhibited the DNA binding activity of recombinant NF-kappaB p50 and p65 homodimers and of p50-p65 heterodimers. Inhibition of NF-kappaB p50 DNA binding by NO-donor compounds involved modification of the conserved redox-sensitive C62 residue, as a C62S p50 mutant was significantly more resistant to SNP-mediated inactivation. Non-reducing SDS-polyacrylamide gel electrophoresis demonstrated that SNP could inhibit p50 DNA binding by mechanisms other than the formation of intersubunit disulphide bonds involving p50 residue C62. Electrospray ionization mass spectrometry of a synthetic NF-kappaB p5O peptide containing the C62 residue suggested that NO gas can modify C62 by S-nitrosylation. This study indicates that NO-donors can directly inhibit the DNA binding activity of NF-kappaB family proteins, suggesting that cellular NO provides another control mechanism for modulating the expression of NF-kappaB-responsive genes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Binding Sites
  • DNA / metabolism*
  • Mass Spectrometry
  • Molecular Sequence Data
  • NF-kappa B / antagonists & inhibitors*
  • NF-kappa B / metabolism
  • NF-kappa B p50 Subunit
  • Nitric Oxide / pharmacology*
  • Nitroprusside / pharmacology
  • Penicillamine / analogs & derivatives
  • Penicillamine / pharmacology
  • Protein Binding
  • Recombinant Fusion Proteins / drug effects
  • Recombinant Fusion Proteins / metabolism
  • S-Nitroso-N-Acetylpenicillamine
  • Transcription Factor RelA


  • NF-kappa B
  • NF-kappa B p50 Subunit
  • Recombinant Fusion Proteins
  • Transcription Factor RelA
  • Nitroprusside
  • Nitric Oxide
  • S-Nitroso-N-Acetylpenicillamine
  • DNA
  • Penicillamine