FIG 2.

Reductase activities of CgMsrA using different reducing powers. (A and B) CgMsrA activities were measured by recording NADPH oxidation at 340 nm. The reaction mixture contained 50 mM Tris-HCl (pH 8.0), 2 mM EDTA, 250 μM NADPH, 2 μM CgMsrA, 100 mM MetO, and the Trx system (4 μM TrxR and 40 μM Trx) (A) or the Mrx1 system (500 μM MSH, 4 μM Mtr, and 40 μM Mrx1) (B). (C and D) Michaelis-Menten plots of CgMsrA activity versus MetO, Trx, and Mrx1. The reaction mixtures contained 50 mM Tris-HCl (pH 8.0), 2 mM EDTA, 250 μM NADPH, 2 μM CgMsrA, 0 to 150 mM MetO, and the Trx system (4 μM TrxR and 40 μM Trx) or the Mrx1 system (500 μM MSH, 4 μM Mtr, and 40 μM Mrx1) (C) or 100 mM MetO and the Trx system (4 μM TrxR and 0 to 120 μM Trx) or the Mrx1 system (500 μM MSH, 4 μM Mtr, and 0 to 120 μM Mrx1 (D). The data are represented as means ± SD of three independent experiments.