Figure 5.

Increase in ionic strength increases the efficiency of Bcl-xL in inhibiting Bax-mediated MOMP. Mitochondrial suspensions were incubated with 17 nM Bax, 120 nM tBid, and varying concentrations of purified Bcl-xL (48, 120, 160, and 240 nM) at either 10 mM KCl buffer (solid line) or 90 mM KCl buffer (dashed line) for 30 min at 30°C. Then, the mitochondria were centrifuged and supernatant assayed for AK release. The results are means ± SE of three experiments.