Figure 2.

The synaptotagmin-1 eC₂AB fragment and complexin-I can bind simultaneously to the SNARE complex. (a,c) Gel filtration profiles of Cpx26-83 (a) or complexin-I (Cpx) (c), eC₂AB fragment and soluble SNARE complex (SC) alone or in different combinations. Elution volumes of molecular weight markers are indicated at the top, and the numbers of collected fractions at the bottom. The concentrations of all proteins in the injected samples were 15 μM. (b) SDS-PAGE analysis of fractions from the chromatograms shown in panels (a) and (c) that contained mixtures of eC₂AB fragment, SNARE complex and Cpx26-83 (left) or complexin-I (right). Proteins were detected with coomassie blue staining. (d) Gel filtration profile of a sample that contained 16 μM SNARE complex, 41 μM complexin-I and 32 μM eC₂AB fragment. The MALS data acquired on the central part of the peak corresponding to the ternary eC₂AB/SNARE complex/complexin-I assembly are shown in blue above the UV absorption profile.