FIG. 6.
Calorimetric traces of the fusion of VSV with vesicles of different PS content at 35oC . The calorimetric traces were obtained after the injection of 10 μl of VSV solution (0.28 mg/ml) into the cell containing 1 mM vesicles of PC-PS (1:3) (A) and PC-PS (3:1) (B) at pH 6.0 or pH 7.5, as indicated in each panel. After the heat due to the VSV dilution, there is a negative heat effect that can be associated with the fusion process. The return to the baseline level indicates that the fusion was complete. At pH 7.5, only the heat effect associated with the VSV dilution and binding to the vesicles is observed. The samples were prepared in 20 mM MES-30 mM Tris buffer, pH 7.5 or 6.0.