D. The in vitro synthesized radioactive Bax proteins with indicated mutations were targeted to the mitochondria in the absence or presence of purified tBid protein, and then labeled with IASD, as in Figure 2B. The IASD-labeled and unlabeled Bax proteins were resolved using either gradient SDS-PAGE or IEF, detected by phosphor-imaging, and indicated by triangles and arrows, respectively. n = 3 for A178C,G179I; 2 for other mutants.E. The IASD labeling data in (D) and the similar data from the independent replicates were quantified to derive the membrane burial indices shown in Appendix Figure S7A, from which the relative membrane burial indices were obtained as described in Figure 2C, and shown. 