Synaptotagmin-1(SYT1) belongs to the synaptotagmin family contains 2 C2 domains. The synaptotagmins are integral membrane proteins of synaptic vesicles thought to serve as Ca(2+) sensors in the process of vesicular trafficking and exocytosis. SYT1 is the master switch responsible for allowing the human brain to release neurotransmitters. Recombinant human SYT1 protein, fused to His-tag at C-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.