FIG. 5.
Influence of Chol and SPM on pH-dependent binding of SIN to liposomes. SIN (trace of [35S]methionine-labeled virus and unlabeled virus [0.5 μM phospholipid]) was incubated with liposomes (200 μM liposomal phospholipid) at pH 5.0 or pH 7.4 at 37°C. Binding of SIN to liposomes was determined by coflotation analysis on sucrose density gradients, as described in Materials and Methods. Bars: a, PC/PE/SPM/Chol (molar ratio, 1.0:1.0:1.0:1.5) liposomes; b, PC/PE/Chol (molar ratio, 1.0:1.0:1.0) liposomes; c, PC/PE/SPM (molar ratio, 1.0:1.0:1.0) liposomes; d, PC/PE (molar ratio, 1.0:1.0) liposomes.