FIGURE 3.

Tomosyn inhibits the SNARE-mediated lipid mixing reaction. A, illustrations of the reconstituted liposome fusion procedures. The t-SNARE liposomes were reconstituted with either syntaxin-4/SNAP-23 or syntaxin-1/SNAP-25, whereas the v-SNARE liposomes were prepared using VAMP2. B, lipid mixing of the reconstituted proteoliposomes in the absence or presence of 5 μm tomosyn. Negative controls: 20 μm VAMP2 CD was added at the beginning of the fusion reactions. Each fusion reaction contained 5 μm t-SNAREs and 1.5 μm v-SNARE. C, initial rates of the lipid mixing reactions shown in B. Data are presented as percentage of fluorescence change per 10 min. Error bars indicate S.D.