Figure 5.
Oxidation-reduction properties of Prx Q. A, Oxidation-reduction titration of Prx Q at pH 7.0. Each reaction mixture contained 100 μg of Prx Q in 1.0 mL of 100 mm MOPS buffer (pH 7.0) containing DTT at a total concentration of 2.5 mm (Eh was adjusted by varying the ratio of reduced:oxidized DTT). Samples were equilibrated for 3.0 h before the addition of monobromobimane (mBBr). B, Effect of pH on the Em value of Prx Q. Reaction conditions were as in A except for the pH buffers used (see “Materials and Methods”).