Fig 3.
Catalysis by ERp protein of the intramolecular rearrangement of the native 2-disulfide intermediate, N′, with both 2.0 mM GSH and 0.5 mM GSSG. The reaction with no enzyme (A), with PDI (B), with ERp72 (C), and with ERp61 (D) are indicated. (E) The kinetics of the native form:total BPTI ratio. The area under the curve of elution profiles corresponding to intermediates (N′, N*, and NSHSH) and native form (N) was measured using National Institutes of Health image. Molecular ratios are indicated in arbitrary values. ERp61 and ERp72 accelerated the conversion of N′ to N, but less efficiently than did PDI, and hardly converted N′ to N*. Open circles, no enzyme; closed circles, 1.5 μM PDI; open squares, 1.5 μM ERp61; closed squares, 1.5 μM ERp72. GSSG, glutathione disulfide; PDI, protein disulfide isomerase; ER, endoplasmic reticulum