Increased S-nitrosylation of parkin and p53 levels in a mouse model of PD. Levels of S-nitrosylated parkin (SNO-parkin), total parkin, p53, and actin were examined by biotin-switch and western blot in mice treated with the nNOS inhibitor 3-Br-7-NI, PQ/MB, or PQ/MB with 3-Br-7-NI (left panel). Ratios of SNO-parkin and total parkin were quantified to indicate the extent of parkin S-nitrosylation under the indicated conditions (center panel). Quantifications of p53 signal were normalized to actin (right panel). Values are mean + SEM, n = 3 mice per condition; * p < 0.05.