Figure 5.

Analysis of the relative contributions of the synaptotagmin-1 C₂ domains to SNARE complex binding. A. Plots of the SMR intensities observed in 1D ¹³C-edited ¹H-NMR spectra of 3 µM synaptotagmin-1 C₂A domain (solid squares), pure C₂B domain (solid cirlces) and impure C₂B domain (open squares) as a function of unlabeled SNARE complex concentration in the presence of 1 mM Ca²⁺. B. ¹H-¹⁵N HSQC spectra of synaptotagmin-1 C₂B domain that was fully purified (red contours) or that was purified by our standard protocol but omitting the final cation exchange chromatography (black contours). The insets show expansions of regions containing cross-peaks that are unique for the purified C₂B domain but exhibit multiplicity in the impure C₂B domain [see ref. (49)].