Human Immunoglobulin G hinge region (IgG hinge)

The Human Immunoglobulin G (IgG) hinge region is a flexible amino acid sequence that connects the antigen-binding (Fab) arms to the constant (Fc) region of the antibody. This region is essential for providing the segmental flexibility required for bivalent binding to antigens and for facilitating interactions with effector molecules such as C1q and Fc gamma receptors (FcγRs) (Vidarsson et al., 2014). While traditionally viewed as a structural component, the IgG hinge has emerged as a therapeutic target for specific enzymes like Imlifidase (IdeS), a protease that cleaves IgG at this site to neutralize pathogenic antibodies (Jordan et al., 2017). By cleaving the hinge, these drugs decouple the recognition and effector functions of IgG, preventing complement-dependent cytotoxicity and antibody-dependent cellular cytotoxicity (von Pawel-Rammingen et al., 2002). This approach is clinically significant in treating antibody-mediated rejection in organ transplantation and severe autoimmune diseases where rapid removal of IgG is necessary (Lonze et al., 2018). Thus, the IgG hinge region is a critical structural and functional element that can be enzymatically manipulated to manage acute immune-mediated conditions.

Other names

IgG hinge domainImmunoglobulin G hingeAntibody hinge region

Site-specific proteolytic cleavage of the IgG heavy chain at the hinge region, resulting in the separation of Fab and Fc fragments and neutralization of antibody effector functions.