β₂-微球蛋白 来源于人类尿液

Research area: Cancer

β2 microglobulin (β2-M) is a polypeptide that associates with the heavy chain of class I major histocompatibility complex (MHC) antigens on the cell surface. It is a non-glycosylated protein, synthesized by all nucleated cells. Its secondary structure comprises of seven β-strands, arranged into two β-sheets connected by a single disulfide bridge.

β₂-Microglobulin from human urine was used to test humoral CSF parameters in the differential diagnosis of hematologic CNS neoplasia. It was also used in the identification of CTL epitopes in hepatitis C virus by a genome-wide computational scanning and a rational design of peptide vaccine.

The interaction of β2 microglobulin (β2-M) with major histocompatibility complex (MHC) is dynamic and plays a critical role in the stability of the MHC antigens and their ability to present peptide antigens in CD8⁺ cells. A transient complex of MHC heavy chain and β₂-M is known to be assembled into the TAP molecule (transporter associated with antigen processing) through interactions with a number of chaperones. Binding of processed peptide releases the Class I-β₂-M complex to the cell surface. Absence of binding leads to degradation in the proteasome. β2-M serves as a regulator of cell survival, proliferation, migration, invasion, apoptosis, angiogenesis, and metastasis in cancer cells. It is also recognized for promoting the growth and survival of stromal cells, such as mesenchymal stem cells (MSCs), osteoblasts, and osteoclasts, thereby supporting cancer bone metastasis.

Prepared by the method of Berggard and Bearn.