Nitric oxide reduces NADPH oxidase 5 (Nox5) activity by reversible S-nitrosylation

► Nitric oxide dose-dependently inhibits NADPH oxidase activity. ► Reduced Nox5 activity was not due to nitration, glutathiolation or phosphorylation. ► Nox5 was S-nitrosylated on at least 4 sites and SNO-Nox5 reduced by C694S mutation. ► Sensitivity to NO inhibition varied across Nox isoforms, Nox1≥Nox3>Nox5>Nox2>Nox4.