Differential effects of substrate-analogue inhibitors on nitric oxide synthase dimerization

► l-NMA not only inhibited iNOS dimerization, but also destabilized its dimeric in immune-activated macrophages. ► This inhibitory effect was correlated with NO production, and these effects were reversed by l-arginine. ► Our results suggest that l-NMA can inhibit NO production via inhibition of iNOS dimerization.