The structural diversity and the biological meaning of antibody

Along with the development of antibody drugs and catalytic antibodies, the structural diversity issue has attracted much attention. Structural diversity(or structural heterogeneity) is generated caused by the modification of different charges, different molecular sizes, and/or modified amino acid residues. Namely, an antibody takes multi-molecular forms in the solution. It is desirable that the antibody and/or the subunits must have a defined structure for practical use. Regarding with the difficult issue on the structural diversity of antibody, we found the interesting phenomena in which copper ion can convert the multi-molecular forms of antibodies to mono-molecular form (1). The ion hugely contributed to the enrichment of the dimer-form and the homogenation of the differently charged full-length of the light chain. The role of copper ion must be significant for preparing a single, defined, not multiple, isoform structure. In addition, we found that the constant region domain (CL) of the antibody light ...