Download MendeleyFcab-HER2 Interaction: a Menage a Trois. Lessons from X-Ray and Solution Studies.
Lobner, E., Humm, A.S., Goritzer, K., Mlynek, G., Puchinger, M.G., Hasenhindl, C., Ruker, F., Traxlmayr, M.W., Djinovic-Carugo, K., Obinger, C.(2017) Structure 25: 878-889.e5
- PubMed: 28528777
- DOI: https://doi.org/10.1016/j.str.2017.04.014
- Primary Citation of Related Structures:
5JIH, 5JII, 5JIK, 5K33, 5KWG - PubMed Abstract:
The crystallizable fragment (Fc) of the immunoglobulin class G (IgG) is an attractive scaffold for the design of novel therapeutics. Upon engineering the C-terminal loops in the CH3 domains, Fcabs (Fc domain with antigen-binding sites) can be designed. We present the first crystal structures of Fcabs, i.e., of the HER2-binding clone H10-03-6 having the AB and EF loop engineered and the stabilized version STAB19 derived by directed evolution. Comparison with the crystal structure of the Fc wild-type protein reveals conservation of the overall domain structures but significant differences in EF-loop conformations. Furthermore, we present the first Fcab-antigen complex structures demonstrating the interaction between the engineered Fcab loops with domain IV of HER2. The crystal structures of the STAB19-HER2 and H10-03-6-HER2 complexes together with analyses by isothermal titration calorimetry, SEC-MALS, and fluorescence correlation spectroscopy show that one homodimeric Fcab binds two HER2 molecules following a negative cooperative binding behavior.
Organizational Affiliation:
Christian Doppler Laboratory for Antibody Engineering, BOKU - University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria; Department of Chemistry, Division of Biochemistry, BOKU - University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria.
