alpha2-Macroglobulin (human) ELISA Kit (10x96T)

alpha2-Macroglobulin (alpha2M), is a 720-kDa homotetrameric glycoprotein composed of four identical 180 kDa subunit. alpha2M shares with other alpha-macroglobulins, like the complement components C3 and C4 and the pregnancy zone protein PZP, an extraordinary binding capacity for a variety of ligands. This allows the alpha-macroglobulins to serve as humoral defense barriers against foreign peptides in the plasma. alpha2M interacts and captures virtually any proteinase, often referred to as a panprotease inhibitor. In the brain of Alzheimer's disease (AD) patients, alpha2M also has been localized to diffuse amyloid plaques, supporting an important role for alpha2M in AD etiopathology. Is able to inhibit all four classes of proteinases by a unique 'trapping' mechanism. This protein has a peptide stretch, called the 'bait region' which contains specific cleavage sites for different proteinases. When a proteinase cleaves the bait region, a conformational change is induced in the protein which traps the proteinase. The entrapped enzyme remains active against low molecular weight substrates (activity against high molecular weight substrates is greatly reduced). Following cleavage in the bait region a thioester bond is hydrolyzed and mediates the covalent binding of the protein to the proteinase.