摘要：The rapid growth of the global HIV/AIDS epidemic makes it a high priority to develop an effective *** a live attenuated or inactivated HIV vaccine is not likely to be approved for clinical application due to safety concerns,HIV virus like particles(VLPs) offer an attractive alternative because they are considered safer since they lack viral *** got a stable eukaryotic cell line by G418 resistance selection,engineered to express the HIV-1 structure protein Gag and Env efficiently and *** confirmed the presence of Gag and Env proteins in the cell culture supernatant and that they could self-assemble into *** VLPs were found to be able to elicit specific humoral and cellular immune response after immunization without any adjuvant.

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 mechanism.