蓝藻抗病毒蛋白-N衍生物的克隆、发酵与纯化

Expression,Fermentation and Purification of Cyanovirin-N Derivative

蓝藻抗病毒蛋白-N(Cyanovirin-N,CVN)能特异性与病毒表面糖蛋白结合,抑制病毒进入宿主细胞及抑制病毒感染细胞与未感染细胞的融合。通过分子设计及优化,在CVN的N-末端连接了5个氨基酸的柔性多肽(GGGGS),构建了SUMO-L5-CVN融合表达系统。SUMO-L5-CVN在大肠杆菌BL21中呈可溶性表达;通过表达条件优化,以0.5 mmol/L IPTG在20℃诱导24 h是最佳的诱导表达条件;SUMO-L5-CVN表达量占菌体总蛋白的30%;经Ni-NTA亲和层析获得融合蛋白SUMO-L5-CVN,SUMO蛋白酶酶切,以及进一步从Ni-NTA亲和层析获得的目的蛋白L5-CVN蛋白纯度>98%。结果表明,低浓度的L5-CVN与流感病毒表面糖蛋白gp120就有较高的亲和力。

CVN acts by binding with high affinity to the viral envelope glycoprotein, thus inhibiting viral invasion and fusion of the virus particle to the target cell. Through molecular design and optimization, a 5-amino acids flexible peptide （ GGGGS ） was linked to the N-terminus of CVN. SUMO-L5-CVN was expressed in the cytoplasm of E. coil BL21 in a soluble form by SUMO fusion expression system. After the optimization of expression conditions, SUMO-Ls-CVN was highly expressed in E. coli BL21 under the induction of IPTG （ 20℃, 24 b, 0.5 mmol/L ）. The fusion protein was expressed up to 30% of the total protein. The recombinant L5-CVN was purified to homogeneity by 2 rounds of Ni-NTA affinity chromatography and one round of SUMO protease cleavage. Nanomolar concentration of L5-CVN have a high affinity with the viral envelope glycoprotein gp120.