Figure 5

IM30-mediated membrane fusion is modulated to some extent by GTP and GDP. Liposome fusion was measured in the presence of 1 µM SynIM30 WT, 2.5 mM nucleotide and 6 mM Mg²⁺. Because of binding of free Mg²⁺ by the nucleotides, “extra” needed Mg²⁺, needed to obtain the same membrane destabilization, was also added (2.5 mM for GDP, 4.25 mM for GTP). The presence of GTP leads to a slight increase in the fusion rate, whereas the presence of GDP leads to a slower fusion process. (SD, n = 3).