Fig. 2
From: Spatiotemporal control of coacervate formation within liposomes
pLL/ATP coacervate formation within liposomes through influx of ATP. a A schematic showing the formation of a pLL/ATP coacervate within a liposome. ATP from the environment diffuses inside the liposome through α-hemolysin pores. It interacts with pLL molecules present inside the liposome, initiating coacervation throughout the liposome. Over time, individual coacervates coalesce to form a single coacervate. b Time-lapse fluorescence images (red: lipid bilayer; green: FITC-pLL) showing the coacervation process inside a liposome. Note the simultaneous formation of multiple coacervates that further coalesce to form one single entity. Time zero (t0) corresponds to the first visible sign of coacervation. c Schematic and a typical example showing coalescence of two coacervates, a characteristic feature of liquid droplets. d Average number of coacervates present inside a liposome as a function of time. After the initial burst of multiple coacervates (~8) throughout the liposome, the average number decreased to about 2 within the next 5 min. e Evolution of the average coacervate size with time. Initially formed small coacervates (~1 µm) subsequently fuse with each other, to ultimately form a ~2 µm coacervate that freely diffuses inside the liposome. f Coacervate-phase intensity versus time (n = 12 liposomes, obtained from a single experiment). The rapid transition from a homogeneous solution to a condensed phase leads to sudden rise in the fluorescence intensity, which plateaus over time. g A plot of the dilute-phase intensity over time (n = 12), showing a complementary rapid decay. The horizontal dashed lines indicate the decrease in the fluorescence intensity just before coacervation takes place, providing evidence for nucleation events. See Methods for details of the analyses involved for panels (d–g). Error bars in (d, e) indicate standard deviations. Dashed vertical lines in (f, g) indicate the onset of coacervation, the plots show the average values, with the shaded regions indicating standard deviations. Source data are provided as a Source Data file
