Macroglobulin Alpha 2 (A2M) Antibody – Mouse Monoclonal

Alpha-2-macroglobulin is a protease inhibitor and cytokine transporter. It inhibits many proteases, including trypsin, thrombin and collagenase. A2M is implicated in Alzheimer disease (AD) due to its ability to mediate the clearance and degradation of A-beta, the major component of beta-amyloid deposits. [provided by RefSeq, Jul 2008]

Function: 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.

Subunit structure: Homotetramer; disulfide-linked. Ref.8 Ref.10

Subcellular location: Secreted Ref.8.

Tissue specificity: Secreted in plasma. Ref.8

Developmental stage: Contrary to the rat protein, which is an acute phase protein, this protein is always present at high levels in circulation.

Sequence similarities: Belongs to the protease inhibitor I39 (alpha-2-macroglobulin) family. [View classification]

Sequence caution: The sequence AAT02228.1 differs from that shown. Reason: Erroneous initiation. Translation N-terminally shortened.The sequence BAD92851.1 differs from that shown. Reason: Erroneous initiation. Translation N-terminally shortened.