Antibodies all have the same basic structure consisting of two heavy and two light chains forming two Fab arms containing identical domains at either end attached by a flexible hinge region to the stem of the antibody, the Fc domain, giving the classical ‘Y’ shape.

To optimize the anti-tumor activity of agonist antibodies’ binding to immunostimulatory TNF receptors, the Fc region of the IgG antibody was engineered to bind more strongly to the FcγRIIB receptor.

The therapeutical antibodies Spesolimab (Spevigo) and Teplizumab (Tzield) have a LALA-modified IgG1 Fc region. Spesolimab targets the IL36 receptor (IL36R) to block IL36-mediated signaling in psoriasis, for which it was approved in 2022.

2023年9月5日 · The Fc region of immunoglobulins allows for the interaction of immune complexes with other phagocytic cells and complement components. The specific biological functions associated with this region are determined by the amino acid sequences of each domain in the constant region.

By binding to specific proteins the Fc region ensures that each antibody generates an appropriate immune response for a given antigen. The Fc region also binds to various cell receptors, such as Fc receptors, and other immune molecules, such as complement proteins.

The functional repertoire of an antibody is dictated by a combination of the fragment antigen-binding (Fab) region, which determines antigen specificity, and the fragment crystallizable (Fc) region, which binds Fc receptors (FcRs) found on immune cells in the mammalian host.

Fc region is the tail region of an antibody that interacts with cell surface receptors called Fc receptors and some proteins of the complement system. This property allows antibodies to activate the immune system. The Fc regions of immunoglobulin Gs bear a highly conserved N-glycosylation site.

F(ab) and Fc Regions. The Y-shape of an antibody can be cleaved into three fragments by the proteolytic enzyme pepsin: two F(ab) regions and an Fc region. The F(ab) regions contain the variable domain that binds to cognate (specific) antigens.

2025年1月10日 · Structurally, Fc receptors are transmembrane proteins with an extracellular domain responsible for binding the Fc region of antibodies. This domain is typically composed of immunoglobulin-like domains, which are crucial for the specificity and affinity of the receptor-antibody interaction. The number and arrangement of these domains can vary ...

2024年9月3日 · Antibodies, a key element of the immune system, play dual roles through two distinct structural regions: the antigen-binding fragment (Fab) and the crystallizable fragment (Fc). These regions not only bind antigens but also trigger …