Figure 2.

tBid binds specifically to mitochondria-like SLBs. (A) Representative confocal images in the absence (left) or presence (right) of a mitochondria-like SLB, incubated for 12 min with 25 nM cBid-Atto647. Images acquired at 635 nm excitation (upper) were used to localize cBid-Atto647, whereas those acquired at 488 nm excitation (lower) were used to confirm the formation of the DiO-labeled SLB. (B) Average intensity profiles along the optical axis of the images shown in A. (C) Average membrane signal, <I_M>, as a function of average solution signal, <I_S>, measured at 635 nm excitation, for SLBs incubated with different concentration of cBid-Atto647 (1–30 nM). Each point represents the mean ± SD of three different images acquired at different locations in the same sample. The continuous line is a linear fit to the data, with a slope of 9.4.