Fig. 1. Characterization of recombinant SNARE proteins used in study. (  A ) Schematics of expression constructs used for synthesis of recombinant rat SNARE proteins. All constructs coded for full-length proteins minus the C-terminal transmembrane domains in rVAMP2 and rSTX-1A (syntaxin 1A). Location of the His⁶tags are denoted. (  B ) Coomassie-stained sodium dodecyl sulfate (SDS)-PAGE of fast protein liquid chromatography buffer-purified recombinant proteins.  Lanes : 1: rVAMP2; 2: rSNAP-25B; 3: rSTX-1A; 4: ternary complex incubated in 0% SDS at 23°C; 5: ternary complex (0.1% SDS); 6: ternary complex (0.5% SDS); 7: ternary complex (0.5% SDS—boiled); migration of size markers in kilodaltons is denoted. (  C ) Western blots of the recombinant SNARE proteins as monomers and in the ternary complex. S = SNAP-25B; Sx = syntaxin-1A; T = ternary complex; Tb = ternary complex boiled; V = VAMP2. (  D ) Circular dichroism spectra of recombinant SNARE proteins and the SNARE complex.