Revealing the Analytical Potential of FcγRIa (CD64) as a Ligand Molecule for IgG1 Capture and Antigen Sensing: Evaluation of FcγRIa ectodomain via Molecular Dynamics

Official URL: https://risc01.sabanciuniv.edu/record=b3205747

Monoclonal antibodies are widely used in many fields such as research, diagnostic, and therapeutic applications. the clinically approved monoclonal antibodies predominantly belong to the IgG1 sub-type. Generally, Protein A ligand is used to capture monoclonal antibodies, but it non-specifically interacts with other molecules. FcRI plays a vital role in the immune system by triggering ADCC and or ADPC. It specifically interacts with a high affinity toward the lower hinge region of the Fc region of IgG1 sub-type antibodies. In this study, we evaluated the potential of Fc gamma receptor I (FcRI) in terms of site-specific IgG1 capture and controlled orientation of IgG1 molecules on the sensor surface to detect their target antigens by SPR assays. Furthermore, we integrated the experimental approaches with computational methods to understand the structure and functional information of Fc and FcRI interactions. The first part of the study consisted of a comprehensive characterization of FcRIa as an affinity ligand for IgG1-type monoclonal antibody binding. The antibody binding potential of FcRIa was assessed with the SPR technique using different immobilization techniques. Assays were performed in parallel with Protein A ligand to compare the antibody binding capacity of FcRIa ectodomain. The final part of the study performed the classical molecular dynamics simulations to investigate the structural features, conformational dynamics, and interactions between FcγRIa with the Fc region of IgG1 in the presence and absence of the D3 domain within FcγRIa ectodomain.