Fc region of immunoglobulin G1 (Fc region (IgG1))

The **Fc region of immunoglobulin G1 (IgG1 Fc region)** is the constant, crystallizable portion of an IgG1 antibody that is composed of the CH2 and CH3 domains of the heavy chain and is responsible for mediating a broad array of immune effector functions[1][3][4][5][6]. The Fc region interacts with various cell surface Fc gamma receptors (FcγRs) on innate immune cells, as well as with complement protein C1q and the neonatal Fc receptor (FcRn), enabling processes such as antibody-dependent cellular cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), antibody-dependent cellular phagocytosis (ADCP), and regulation of antibody serum half-life[1][2][3][4][5][7]. The Fc region is highly conserved and contains a critical N-glycosylation site that modulates its interactions, effector functions, and potential immunogenicity[1][5]. It is a principal molecular target for the design of therapeutic antibodies and engineered antibody fusion proteins, and its structure–function relationships are central to the safety and efficacy profile of many immunotherapies[3][4].

Other names

Fc fragment of IgG1IgG1 Fcfragment crystallizable region (IgG1)Fc domain of IgG1

Engagement with Fc gamma receptors (FcγRs) on immune effector cells to mediate ADCC or ADCP; Binding to complement protein C1q to initiate complement cascade (CDC); Interaction with neonatal Fc receptor (FcRn) for antibody recycling and extended half-life; Binding to protein A/G as part of research and purification workflows