Figure 5. Double reciprocal plot of the arsenic methylation rate versus the concentration of SAM.

Reaction mixtures (100 μl) containing 11 μg C85S, 1 μM iAs³⁺, and 7 mM GSH in PBS (25 mM, pH 7.0) were incubated with various concentrations of SAM for 2 h with H₂O₂ treatment before analysis. Values are the averages ± S.D. of three independent experiments performed by three independently purified proteins.