Soluble Expression, Purification and Characterization of Single-chain Fv Catalytic Antibody（sFv-2F3）

To find optimal conditions for expressing the soluble form of sFv-2F3 and to study the purification andproperty of its derivative Se-sFv-2F3, the preferred expression conditions were investigated by means of or-thogonal design. These culture conditions included incubation temperature, inducer concentration, inductiontime and cell concentration. The evaluation of expression was accomplished by the analysis of whole celllysates and the yield of soluble sFv-2F3 was calculated according to the analysis of Profinder(FTI-500,Phar-macia). The purification procedure was carried out via a two-step purification procedure consisting of ion-ex-change chromatography, followed by immobilized metal affinity chromatography(IMAC). The antioxidantefficacy of Se-sFv-2F3 was demonstrated by the determination of the content of the main product of lipid per-oxidation, MDA, the viability of cells and the activity of LDH. We obtained the preferred culture conditionsto grow the engineered bacteria and the procedure for preparing soluble sFv-2F3 and confirmed the antioxi-dant efficacy of Se-sFv-2F3.