TABLE 1.
Effects of DOPE on fusion kinetics
| Full fusion
|
Hemifusion
|
||||||||
|---|---|---|---|---|---|---|---|---|---|
| Lipid composition | Ntotal* | ffus* (%) | kfus†(s−1) | fhemi*(%) | khemi† (s−1) | fcore*(%) | kcore† (s−1) | fdead*(%) | |
| t0PE | v0PE | 138 | 96 | 37 ± 15 | 4 | — | — | — | — |
| v20PE | 97 | 92 | 32 ± 15 | 8 | — | — | — | — | |
| v40PE | 121 | 79 | 30 ± 15 | 21 | 3.2 ± 1.0† | 14 | — | 7 | |
| v60PE | 195 | 79 | 34 ± 15 | 21 | 12 ± 5† | 13 | 0.6 ± 0.2 | 8 | |
| t20PE | v0PE | 257 | 96 | 28 ± 15 | 4 | — | — | — | — |
| v20PE | 225 | 81 | 44 ± 15 | 19 | 15 ± 3† | 14 | 1.1 ± 0.3 | 5 | |
| v40PE | 129 | 62 | 50 ± 15 | 38 | 14 ± 4† | 22 | 0.8 ± 0.2 | 16 | |
| v60PE | 156 | 55 | 31 ± 15 | 45 | 17 ± 3† | 12 | 0.6 ± 0.2 | 33 | |
Total number of fusion events observed from three to five different t-SNARE bilayers at each lipid composition. These are classified as full (prompt) fusion or hemifusion events, occurring with fractions ffus and fhemi respectively, according to whether or not a bright core remains behind after the first wave of lipids is released. The fraction fhemi is further partitioned into productive or dead-end hemifusion events for which, respectively, the core does (fcore) or does not (fdead) decay as a second wave during the 20-s movie. Normalization is chosen so that fhemi = fcore + fdead.
Best fits of a single exponential decay model to the first three bins of the histograms shown in Supplementary Material Figs. S4–S6. See text for model details.