FeIII + NADPH -> FeII + NADPplus
FeII + O2 -> FeII_O2
FeII_O2 -> FeIII_star
FeIII_star + (1/2)*NADPH -> FeII_star + (1/2)*NADPplus
FeII_star + O2 -> FeII_star_O2
FeII_star_O2 -> FeIII_NO + citrulline
FeIII_NO -> FeIII + NO
FeIII_NO + (1/2)*NADPH -> FeII_NO + (1/2)*NADPplus
FeII_NO -> FeII + NO
FeII_NO + O2 -> FeIII + NO3