Fc–Protein A interface on ferritin nanoparticle scaffold (SpA-Fn) (SpA-Fn)

The Fc–Protein A interface on a ferritin nanoparticle scaffold is a bioengineered molecular platform designed for the precise, oriented display of antibodies (Kim et al., 2018). Ferritin is a ubiquitous protein that self-assembles into a spherical, 24-subunit nanocage, providing a stable and biocompatible template for nanotechnology applications (Wang et al., 2017). By genetically fusing the IgG-binding domains of Staphylococcus aureus Protein A (such as the B or Z domains) to the surface of the ferritin subunits, researchers create a scaffold capable of capturing the Fc region of monoclonal antibodies (Deis et al., 2015). This specific interface ensures that the antibody's antigen-binding fragments (Fab) are oriented outward, maximizing their ability to interact with target cells or pathogens (Choi et al., 2019). This platform is primarily used in the development of targeted therapeutics and diagnostics, where the multivalent display of antibodies on the nanoparticle surface significantly increases binding avidity compared to monovalent antibodies (Kanekiyo et al., 2013). While not a therapeutic target itself, this construct serves as a sophisticated delivery vehicle for treating various diseases, including cancer and infectious disorders. The use of ferritin as a scaffold minimizes toxicity, though the immunogenicity of the bacterial Protein A components remains a consideration for clinical translation (Holeiter et al., 2022).

Other names

Protein A-ferritin nanocageSpA-ferritin scaffoldAntibody-displaying ferritin nanoparticleZ-domain ferritin nanoparticle

The interface facilitates the oriented, non-covalent attachment of monoclonal antibodies to a nanoparticle surface, enhancing binding avidity through multivalent display and improving the efficiency of targeted drug delivery (Kim et al., 2018).