SNAP-25 is a presynaptic plasma membrane protein essential for synaptic vesicle fusion and neurotransmitter release . The membrane proteins SNAP-25, synaptobrevin and syntaxin make up the core complex (SNARE) essential for docking and holding synaptic vesicles at the pre synaptic membrane. SNAP-25 gene was amplified by PCR from C.elegans and cloned into an E. coli expression vector. SNAP-25 was purified by using conventional chromatography techniques.