Generation of high-quality antigen is an inherent challenge in therapeutic antibody discovery, especially for difficult targets like polytopic membrane proteins. DNA immunizations rarely produce the titers achieved with protein antigens, and peptides derived from extracellular loops often fail to mimic the epitopes of a full-length membrane protein. Ligand’s Ab Initio antigen platform addresses this problem by providing access to high-quality, functionally validated membrane protein antigens.
The Ab Initio platform produces full-length membrane proteins, including G protein-coupled receptors (GPCRs), in a wide variety of formats. These antigens can be purified and reconstituted in proteoliposomes, detergent micelles and nanodiscs, or secreted from cells as virus-like particles. For each format, proper antigen folding and activity are verified. Ligand also offers the option of displaying antigen in a particular conformation through the use of protein or small molecule conformational chaperones. The high quality, stability and variety of available formats maximize the chance of success in generating a robust immune response with any of the OmniAb antibody platforms.