Anti-Rat β-2-Microglobulin (Clone 4C9) – Biotin

Soluble neonatal Fc receptor (FcRn)

This Biotinylated antibody is formulated in 0.01 M phosphate buffered saline (150 mM NaCl) PBS pH 7.4, 1% BSA and 0.09% sodium azide as a preservative.

Liquid

This biotinylated antibody is stable when stored at 2-8°C. Do not freeze.

Research Use Only

2 – 8° C Wet Ice

4C9 activity is directed against rat β-2-microglobulin that is free or complexed with the FcRn heavy chain.

Neonatal Fc receptor (FcRn) is a 52 kDa membrane bound heterodimeric glycoprotein composed of a heavy and light chain, with the latter being β-2-microglobulin¹. FcRn plays a role in the regulation of IgG catabolism and is located in the endosome where it binds to Fc and IgG. β-2- microglobulin also associates with class I major histocompatibility complex molecules, which are structurally similar to FcRn². In this capacity, β-2-microglobulin plays an important role in tumor antigen presentation and immune surveillance³.

4C9 was generated by immunizing BALB/c mice with soluble FcRn². Splenocytes were fused with HL-1 murine myeloma cells. 4C9 is able to bind to β-2-microglobulin as well as FcRn heterodimers in ELISA tests, can immunoprecipitate soluble FcRn heterodimers, and can also stain lipid-linked rat β-2-microglobulin (β2m-DAF), truncated FcRn heavy chain paired with β2m-DAF, and lipid-linked FcRn heavy chain paired with unaltered β-2-microglobulin.

4C9 blocks binding of IgG to FcRn in vitro² and FcRn blockade has been shown to have a positive effect on IgG-mediated autoimmune diseases¹. In support of this, 4C9 induces a transient and dose-dependent increase in the elimination of exogenously administered antimethotrexate IgG in rats⁴.

β-2-microglobulin has cytoplasmic and membranous expression in most cell types and can be secreted to blood.

Leukocytes, platelets, endothelial cells and epithelial cells

1 Low SC, Mezo AR. AAPS J. 11(3):432-434. 2009.
2 Raghavan M, Chen MY, Gastinel LN, et al. Immunity. 1(4):303-315. 1994.
3 Wang H, Liu B, Wei J. Cancer Lett. 517:96-104. 2021.
4 Getman KE, Balthasar JP. J Pharm Sci. 94(4):718-729. 2005.