Self-assembly of antibodies by chemical induction

The ability to clone and express the variable (VH & VL) and constant (CH & CL) domains of monoclonal antibodies has made the construction of genetically engineered antibodies possible.[1-3] Antibody fragments, such as Fabs, have been fused to self-assembling protein domains such as leucine zipper regions of the transcription factors or to the CL and CH1 domains of IgG.[4, 5] Recombinant antibodies, referred to as single chain antibodies (scFv's), have been constructed by fusing the VH and VL domains of an antibody variable region (Fv) via a peptide linker. This advance resulted in the development of a variety of approaches for the preparation of the corresponding fusion relatives, diabodies (bivalent) and tandabs (tetravalent) consisting of a single polypeptide.[6-10] Although the current methods of preparing recombinant antibodies have a variety of advantages, in general control over their assembly and disassembly is not possible without resorting to conditions necessary for protein unfolding. Since the molecular weight and dimensions of engineered antibodies is a significant determinant of their in vivo avidity, biodistribution and pharmacokinetics, a method allowing these parameters to be temporally altered by chemically controlled assembly and disassembly would in principle enhance the therapeutic and diagnostc utility of recombinant antibodies[11, 12].