Protein engineering for self-assembling antibody molecules in an oriented manner

Two types of protein engineering have been developed for self-assembling antibody (IgG) molecules in an oriented manner. The first is to tag a cysteine group to Protein A which has a specific affinity to the Fc part of IgG. The cysteine-tagged Protein A was self-assembled on the gold surface, which was followed by self-assembling of IgG to face the antigen recognition sites to the solution phase. The second is concerned with tailing a single chain antibody by lipid at the one terminal and the hexahistidinyl group at the other. The lipid and histidine-tailed single chain antibody was embedded in a liposome to make the antigen recognition site appear on the outsphere, which was immobilized on the Ni-treated mica surface through chelating of the histidine tail. The individual liposome was clearly imaged by a tapping mode of AFM.