Figure 2
Gene construct and purification of bispecific tandem single-chain variable fragment (scFv)-Fc fusion protein. (a) Arrangement of genes in the pCEP4 vector. Pcmv denotes the cytomegalovirus promoter. LS denotes the leader sequence of the human immunoglobulin (Ig) κ-chain. VL and VH denote the variable light and heavy chains of Ig, respectively. A linker consisting of (Gly-Gly-Gly-Ser)3 was inserted between the two scFvs. Hinge denotes the hinge sequence of human IgG1. Two constant domains of rabbit IgG, CH2 and CH3, were employed. (b) Anti-C5 × anti-cotinine bispecific tandem scFv-Fc fusion protein was purified by protein A affinity chromatography and subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. Lane 1 was loaded with the flow-through fraction. Lanes 2 and 3 were loaded with purified protein at two different concentrations.
