Immunoglobulin G2

Athens Research

Immunoglobulin G2

9

Glycoproteomics, Inflammation, Biotherapeutics, In Vitro Diagnostic, Antimicrobial, Infection,

Research Use Only

≥ 95% by SDS-PAGE

Serum IgG2 constitutes approximately 23% of total immunoglobulin G and is distinguished by a truncated 12-amino-acid hinge region with a poly-proline helix stabilized by four interchain disulfide bonds. This rigid structure limits Fab arm flexibility, reducing Fcgamma receptor (FcgammaR) binding and complement activation compared to IgG1/IgG3. However, IgG2 excels in targeting repetitive carbohydrate antigens on encapsulated bacteria like Streptococcus pneumoniae and Haemophilus influenzae, forming high-avidity interactions critical for polysaccharide immunity. Its Fc domain binds FcgammaRIIA-H131 with moderate affinity, enabling phagocyte-mediated pathogen clearance in specific contexts. Deficiency in IgG2 (less then2.1 g/L) impairs anti-polysaccharide responses, increasing susceptibility to recurrent sinopulmonary infections and invasive bacterial diseases. This deficiency often coexists with IgG4 or IgA deficits, complicating immune competence. Clinically, serum IgG2 quantification aids in evaluating humoral function, particularly in patients with chronic infections or hypogammaglobulinemia. Therapeutically, IgG2’s reduced Fc-mediated effector functions are exploited in oncology. Panitumumab, an IgG2 anti-EGFR monoclonal antibody, minimizes cytokine release syndrome while retaining tumor-targeting efficacy. Its inefficient FcRn-mediated transcytosis-attributed to the absence of Gly236 in the hinge-also results in lower placental transfer (~50% maternal levels), reducing fetal exposure risks. Emerging engineering strategies leverage IgG2’s structural stability for prolonged serum half-life and minimized off-target activation, enhancing therapeutic safety profiles.

more then 1 year

Source human plasma non-reactive for HBsAG, anti-HCV, anti-HBc, and negative for anti-HIV 1 & 2 by FDA approved tests.

≤ -80° C

12352202