FIGURE 5.

Fluorescence emission spectra of an equimolar mixture of two vesicle populations (NBD-PE/POPC/cholesterol and rhodamine-DHPE/POPC/cholesterol) in the absence (−PP1) and presence (+PP1) of PP1 after 0.25, 2, 6, 20, and 40 h of incubation at room temperature under gentle agitation. Excitation was set at 450 nm. Peaks at 525 and 585 nm, measured at room temperature under gentle stirring, correspond to NBD-PE and rhodamine-DHPE emission, respectively. Fluorescence intensity at 525 nm is normalized to unity. The PP1-induced energy transfer from NBD-PE to rhodamine-DHPE is clearly observable at >6 h.