B2M Human
Description
Human Beta-2 Microglobulin produced in Human urine from patients with tubular proteinuria having a molecular mass of 12KDa.
Product Specs
Product Science Overview
B2M is associated with the alpha chain of MHC class I molecules, but unlike the alpha chain, it does not have a transmembrane region . The MHC class I molecule consists of three alpha domains (α1, α2, and α3) and the B2M protein, which lies beside the α3 chain on the cell surface . This association is essential for the stability and expression of MHC class I molecules on the cell surface .
In addition to its role in MHC class I molecules, B2M also associates with other class I-like molecules such as CD1, MR1, the neonatal Fc receptor (FcRn), and Qa-1 . It is involved in regulating the expression of hepcidin in the liver, which in turn controls iron homeostasis by targeting the iron transporter ferroportin for degradation .
B2M levels in the blood and urine can be indicative of various medical conditions. Elevated levels of B2M are often associated with certain blood and bone marrow cancers, such as multiple myeloma, chronic lymphocytic leukemia (CLL), and certain types of lymphoma . It is used as a tumor marker to help assess the severity and progression of these cancers .
In patients undergoing long-term hemodialysis, B2M can aggregate into amyloid fibers, leading to a condition known as dialysis-related amyloidosis . This condition results in the deposition of amyloid fibers in joint spaces, causing pain and other complications .
The B2M tumor marker test measures the amount of B2M in body fluids, typically blood, urine, or cerebrospinal fluid (CSF) . This test is particularly useful for monitoring the progression of blood and bone marrow cancers, determining the effectiveness of treatment, and predicting the behavior of the cancer . It can also help detect whether cancer has spread to the brain or spinal cord .
Animal models deficient in the B2M gene have been developed to study its function. These models have shown that B2M is necessary for the cell surface expression of MHC class I molecules and the stability of the peptide-binding groove . In the absence of B2M, very limited amounts of MHC class I molecules can be detected on the cell surface, leading to a condition known as bare lymphocyte syndrome (BLS) . This condition impairs the development of CD8+ T cells, which are crucial for acquired immunity .
