Figure 3.

Cholesterol enhances the efficiency of single-particle IAV lipid mixing, whereas the rate of lipid mixing is independent of target membrane cholesterol composition. (A) Wait times for individual lipid mixing events are plotted as cumulative distribution functions (CDFs). From 10 to 40 mol % cholesterol, the rate of IAV lipid mixing is the same within bootstrap resampling error (95% confidence intervals, dashed lines; see Fig. S7 for individual CDFs). (B) In the presence of native viral receptor GD1a, the rate of lipid mixing is also unaffected by increasing the ratio of cholesterol in the target membrane within bootstrap resampling error (95% confidence intervals, dashed lines). (C) The relative efficiency or fraction of target vesicles that undergo dequenching increases four-fold as the mole percentage of cholesterol in DNA-tethered target vesicles increases. For (C) and (D), the lipid mixing efficiency to membranes containing 10 mol % cholesterol is normalized to 1, and points represent the average efficiency value ± bootstrap resampling error. (D) When target membranes contain GD1a, the relative efficiency of lipid mixing also increases four-fold. Kinetic data for each composition were compiled from at least two independent viral preparations. To see this figure in color, go online.