Ni2+, a toxic and carcinogenic pollutant and one of the leading causes of contact dermatitis, is shown to inhibit neuronal nitric oxide synthase (nNOS) in a competitive, reversible manner with respect to the substrate L-arginine (Ki = 30 ± 4 μM). The IC50 values were dependent on calmodulin (CAM) concentration, but proved independent of Ca2+, tetrahydrobiopterin (BH4) and other essential cofactors. Ni2+ also inhibited CAM-dependent cytochrome c reduction, NADPH oxidation, and H2O2 production by nNOS. Overall, the action profile of Ni2+ was suggestive of an unusual, double-acting inhibitor of nNOS affecting L-arginine-binding and Ca2+/CAM-dependent enzyme activation.
|Number of pages||5|
|Journal||Biochemical and Biophysical Research Communications|
|Publication status||Published - 2001|
- Neuronal nitric oxide synthase inhibition
- Nickel ions
ASJC Scopus subject areas
- Molecular Biology