Figure 4.

Effect of other transition metals on iNOS activity. The indicated metals were added as their chloride salts to the given concentration; the iNOS concentration was 125 nM. All of the assays were carried out at 37°C for 3 min, and the final concentrations of the other components were as follows: 250 μM l-[¹⁴C]arginine (1.5 mCi/mmol), 25 μM H₄B, 250 μM DTT, and 1 mM NADPH. All reactions were carried out in 50 mM Hepes buffer, pH 7.4, that had been pretreated with Chelex-100, and the reactions were initiated with NADPH.