高等学校化学研究 ›› 2011, Vol. 27 ›› Issue (5): 813-819.
WANG Cheng1,3, WAN Pei1, GONG Ping-sheng1, LÜ Li-min1, XU Ya-wei1, ZHAO Yang1, HE Bo1, ZHAO Gang1, YAN Gang-lin1*, MU Ying1,2*, LÜ Shao-wu1 and LUO Gui-min1
WANG Cheng1,3, WAN Pei1, GONG Ping-sheng1, LÜ Li-min1, XU Ya-wei1, ZHAO Yang1, HE Bo1, ZHAO Gang1, YAN Gang-lin1*, MU Ying1,2*, LÜ Shao-wu1 and LUO Gui-min1
摘要: In order to enhance the glutathione peroxidase(GPX) catalytic activity of the selenium-containing single-chain variable fragments(Se-scFv), a novel human scFv was designed on the basis of the structure of human antibody and optimized via bioinformatics methods such as homologous sequence analysis, three-dimensional(3D) model building, binding-site analysis and docking. The DNA sequence of the new human scFv was synthesized and cloned into the expression vector pET22b(+), then the scFv protein was expressed in soluble form in Escherichia coli BL21(DE3) and purified by Ni2+-immobilized metal affinity chromatography(IMAC). The serine residue of scFv in the active site was converted into selenocysteine(Sec) with the chemical modification method, thus, the human Se-scFv with GPX activity was obtained. The GPX activity of the Se-scFv protein was characterized. Compared with other Se-scFv, the new human Se-scFv showed similar efficiency for catalyzing the reduction of hydrogen peroxide by glutathione. It exhibited pH and temperature dependent catalytic activity and a typical ping-pong kinetic mecha- nism.