Molecular analysis of heavy chain-only antibodies of Camelus bactrianus

In this work, IgG content and structures of antigen-binding domains and hinge regions of different IgG subtypes of Camelus bactrianus were analyzed in detail for the first time. Our data demonstrate that C. bactrianus contains a very large amount of heavy chain-only antibodies that can be used as a source of VHH domain-containing molecules. Despite some minor sequence differences identified in this study, C. bactrianus VHH domains possess principally the same unique features as those of C. dromedarius and the llama. These features are important for developing an efficient phage display-based anti- body selection technology. We conclude that C. bactrianus is a very suitable animal to raise an immune response that serves as a source to identify antigen-specific VHHs selected after phage display.