Figure 1.

Effects of PN and TNM on GS activity and nitration. Purified MtGS1a or MtGS2a was incubated with PN (A) or TNM at pH 8 (B) at increasing concentrations, assayed for GS transferase activity, and immunodetected with an anti-3-nitrotyrosine specific antibody (NO₂-Tyr). Loading controls were obtained by immunoblotting the membranes with anti-GS1 or anti-GS2 antibody (GS1 or GS2, respectively). GS activity was normalized to that found in the absence of NO donor and is represented as means ± sd of at least three independent experiments, assayed in triplicate. The average initial GS activities were 0.36 and 0.1 μmol min⁻¹ μg⁻¹ protein for MtGS1a and MtGS2a, respectively.