(A–B) FRET efficiencies observed in titrations of WT C2AB* with solubleSC, cisSC-PC-NDs (containing only PC) or cisSC-PC/PS/PIP2-NDs (containing 15% PS,1% PIP2, 84% PC) labeled with TMR at residue 76 of SNAP-25 in the presence of 1 mM EGTA (A) or 1 mM Ca2+ (B). (C–H) FRET efficiencies in analogous titrations of WT, R398Q/R399Q (RQRQ), R322E/K325E (REKE) or E295A/Y338W (EAYW) C2AB* with solubleSC (C–D), cisSC-PC-NDs (E–F) or cisSC-PC/PS/PIP2-NDs (G–H) in the presence of 1 mM EGTA (C, E, G) or 1 mM Ca2+ (D, F, H). All data were fit with a Hill equation (see Materials and methods).
Figure 8—source data 1. Source data for Figure 8.