Alpha 2-macroglobulin

Alpha 2-macroglobulin (A2M) is a large plasma protein found in the blood. It is produced by the liver and is a major component of the alpha globulin protein family. A2M is known for its ability to inhibit a broad spectrum of proteases, a type of enzyme that breaks down proteins and peptides.

Structure

A2M is a large protein, composed of four identical subunits. Each subunit is made up of about 1450 amino acids. The protein has a unique "bait-and-trap" mechanism, which allows it to capture and neutralize a wide range of protease enzymes.

Function

The primary function of A2M is to inhibit proteases. Proteases are enzymes that break down proteins and peptides, and they play a crucial role in many biological processes, including digestion, immune response, and cell signaling. By inhibiting these enzymes, A2M helps to regulate these processes and prevent excessive protease activity.

A2M is also involved in the transport of various hormones and growth factors in the blood. It binds to these molecules and carries them to their target cells.

Clinical significance

Abnormal levels of A2M have been associated with a variety of diseases. High levels of A2M can be seen in nephrotic syndrome, while low levels can be seen in liver disease and malnutrition. A2M levels can also be affected by inflammation and infection.

In addition, mutations in the A2M gene have been linked to Alzheimer's disease. Some studies suggest that A2M may play a role in the clearance of amyloid beta, a protein that forms plaques in the brains of Alzheimer's patients.

See also

• Protease inhibitor
• Alpha globulin
• Plasma protein