FIGURE 3.

Concentration dependence of the rate of S-nitrosation of Cys⁴⁷ reveals a multistep mechanism. 1 μm C101S GSTP1-1 was mixed with varying concentrations of GSNO (closed circles) or CysNO (open circles) under pseudo-first order conditions at 37 °C. The primary data were fit to a double exponential function. One exponential term was fixed to the observed nitrosation rate of C47S/C101S GSTP1-1, and the second rate is reported here as k_obs, representing the nitrosation of Cys⁴⁷ alone. The data in the figure were fit to Equation 2.