immunoglobulin F(ab)2 fragments

Immunoglobulin F(ab)2 fragments are divalent antibody fragments generated by the enzymatic digestion of whole immunoglobulin G (IgG) with the protease pepsin, which removes most of the Fc region while leaving two antigen-binding Fab portions linked by disulfide bonds[1][3][5]. These fragments retain the antigen-binding specificity of whole antibodies but lack the Fc-mediated effector functions, resulting in reduced non-specific binding to Fc receptors on cells such as macrophages, dendritic cells, and B cells. This enhances their specificity in diagnostic, therapeutic, and research applications, improves tissue penetration, and reduces immune activation or anti-Fc interference[1][3][5]. F(ab)2 fragments are used in immunohistochemistry, immunoprecipitation, in vivo neutralization of pathogens and toxins, and as antivenoms, among other applications[1][3]. Therapeutically, species-specific or heterologous F(ab)2 fragments have been explored or used for neutralizing viruses (e.g., SARS-CoV-2, feline calicivirus), toxins, and venoms, showing efficacy in animal models[4][9].

Other names

F(ab')2 fragmentsF(ab)2 antibody fragmentsimmunoglobulin G F(ab')2 fragments