This soluble wild-type human neonatal Fc receptor (FcRn) is supplied at 2mg/ml in PBS pH 7.4. The FcRn in produced in HEK293E cells.
FcRn is a protein encoded by the FCGRT gene. FcRn binds IgG and albumin at acidic pH of 6.0–6.5 but not at neutral or higher pH. FcRn is involved in salvage of IgG and albumin through endocytosis in endothelial cells. Fc receptors in the acidic endosomes bind to IgG or albumin internalized through pinocytosis, recycling it to the cell surface, releasing it at the basic pH of blood, thereby preventing it from undergoing lysosomal degradation. It has been shown that conjugation of some drugs to the Fc domain of IgG and to albumin significantly increases their half-life, likely through this mechanism.