Figure 7.

Fusion induced from HA4*. HA4* was generated by decreasing pH to 4.8 for 10 min at 4°C before reneutralization. (A) Little fusion occurred by increasing the temperature to 23°C (first column), but extensive fusion occurred by increasing the temperature to 37°C (first bar, second column). Adding 0.1 mg/ml proteinase K for 10 min at 4°C abolished the ability of fusion to occur when the temperature of HA4* was increased to 37°C (second bar of second column) but only slightly inhibited CPZ-induced aqueous dye transfer (third column). (B) Generating HA4* and then increasing the temperature to 37°C resulted in extensive lipid and aqueous dye transfer (first column). But the addition of LPC severely inhibited aqueous dye transfer (second column, hatched bar) but only moderately prevented lipid dye transfer (open bar).