Figure 4.

Antibodies specific for endobrevin prevent formation of SDS-resistant SNARE complexes with SNAP-25 and syntaxin 1A. Endobrevin was preincubated with affinity-purified antibodies (IgG) or Fab fragments specific for endobrevin (eb) or synaptophysin (syp) followed by the addition of preassembled SNAP-25/syntaxin 1 complexes. Formation of SDS-resistant complexes was monitored by immunoblotting with the use of an antibody specific for syntaxin 1. SDS-resistant core complexes are dissociated by boiling (left lane; cf. Hayashi et al., 1994).