Nitric-Oxide Synthase Activity in the Photomorphogenesis of Neurospora сrassa

Nitric-oxide synthase activity was detected in Neurospora crassa cells with the measurement of the conversion of 3H-L-arginine to 3H-L-citrulline. Some characteristics of this activity (sensitivity to calcium ions, action of specific enzyme inhibitors, and western blot analysis) were similar to those of an inducible enzyme found in mammals. According to western blotting, the molecular weight of NO synthase was around 130 kDa. No light-dependent changes in the specific activity of NO synthase were revealed in the photocarotenogenesis and photoconidiation of N. сrassa.