Single-chain Fv with Fc fragment of the human IgG1 tag: Construction, Pichia pastoris expression and antigen binding characterization

We report two expression vectors in Pichia pastoris that direct the synthes is of recombinant single chain antibody variable region (scFv), derived fro m anti-Z-DNA monoclonal antibody Z22, The first vector codes for a scFv fus ed to the Ig binding domain of staphylococcal Protein A. The second vector codes for the scFv fused to the Fc fragment of the human IgG1, The fusion p artner simplified the detection and purification of the secreted protein. T hese constructs yielded high level expression of an scFv with specific bind ing activity toward a Z form of DNA, with binding activity comparable to th at of the scFv molecule produced in an Escherichia coli expression system a nd the original monoclonal antibody.