Fig. 5.

FCS analysis of SMALP-SNAP-ABCG2 and the binding of BODIPY-prazosin. (A) SMALPs were prepared from ABCG2-SNAP expressing cells, labelled with SNAP-Surface AlexaFluor 647 as described in Methods, and fluorescence fluctuations (upper) were recorded and autocorrelation curves generated. (B) Fluorescence fluctuations (upper) and subsequent autocorrelation curves (lower) were obtained for BODIPY-prazosin (50 nM) in the absence (green) and presence (blue) of unlabelled SMALP-ABCG2-SNAP, showing the presence of an additional slower component in the presence of purified ABCG2, representing bound BODIPY-prazosin. Data are from a single experiment representative of those described in Fig. 6.