FIG. 7.

Effects of preincubation with DTT and CH₃Cl on the activation of methyltransferase. (a) Effect of preincubation for 60 min at 25°C with 0.5 mM CH₃Cl and different concentrations of DTT in 50 mM phosphate buffer (pH 7.0) on the activity of methyltransferase in the standard assay. (b) Effect of preincubation for 60 min at 25°C in 50 mM phosphate buffer (pH 7.0) with 0.5 mM CH₃Cl, 5 mM DTT, or 0.5 mM CH₃Cl plus 5 mM DTT on the activity of methyltransferase in the standard assay.