β2-Microglobulin Protein (Active)

Beta-2-microglobulin (B2M) is a serum protein found in association with the major histocompatibility complex (MHC) class I heavy chain on the surface of nearly all nucleated cells. B2M gene contains 4 exons and spans approximately 8 kb. The neonatal Fc receptor (FcRn) is a heterodimer of a nonclassical MHC class I alpha and B2M that binds the 2 most abundant serum proteins, IgG and albumin, after their constitutive cellular uptake. FcRn binds both proteins, thus acting as a salvage pathway, protecting them from lysosomal degradation and extending the catabolic half-lives of both proteins.Beta-2-microglobulin had been found in the serum of normal individuals and in the urine in elevated amounts in patients with Wilson disease, cadmium poisoning, and other conditions leading to renal tubular dysfunction.

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