Fig. 2.
(A) Schematic depicting the influence of GSH on the catalytic turnover of Ero1α in vitro. The resulting high concentration of PDIred exerts a stimulatory effect on Ero1α by catalyzing thiol-disulfide exchange at the regulatory disulfide between Cys208 and Cys241 (see main text for detailed models). (B) O2 consumption was monitored over time in a mixture of 2 μM Ero1α-AA (solid line) or Ero1α-AASS (dashed line), 10 μM PDI, and 10 mM GSH. (C) Consumption of NADPH coupled to catalysis by Ero1α-AA (solid line) or Ero1α-AASS (dashed line) (see Materials and Methods; 2 μM Ero1α variants, 10 μM PDI, 1 mM GSH, 1 U glutathione reductase, 200 μM NADPH) was detected by following the absorbance at 340 nm.