A simple and efficient process of two-step purification of soluble TRAIL protein was established. The purity of 95 ％ and the total recovery of 40％ were obtained. This process was suitable for industrialized manufacturing crystallographic. Studies showed that the soluble TRAIL had a homotrimeric structure, and an internal zinc atom was bound by the cysteine residues at position 230 of each subunit, which was crucial for trimer stability and biologic activity.TRAIL was not a stable protein, but a phenomenon was demonstrated that the addition Zn2 + of molar ratio to TRAIL monomer with 2:1 in purified TRAIL solution and simultaneous addition of 25 mmol/L L-Arg and 50 mmol/L L-Glu to the purified TRAIL could dramatically stabilize its activity and reduce aggregation and precipitation.%大肠杆菌发酵表达的TRAIL蛋白经过两步纯化可得到纯度95%以上的活性蛋白,得率为40%.天然TRAIL蛋白为同源三聚体形式,在三聚体中心隐蔽结合Zn<'2+>,Zn<'2+>可维持TRAIL蛋白天然结构的稳定性.研究发现在纯化后的重组可溶性TRAIL蛋白中添加Zn<'2+>,并且Zn<'2+>与TRAIL单体的摩尔比例达到2:1时,TRAIL蛋白的活性达到最高.本文初步研究了TRAIL蛋白的体外活性稳定性问题,发现在添加了最适Zn<'2+>后的TRAIL蛋白保存溶液中添加25 mmol/L L-Arg与50 mmol/L L-GIu有助于抑制TRAIL蛋白活性下降、并可能长期稳定蛋白活性.
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