Alpha 1-antichymotrypsin

Alpha 1-antichymotrypsin is an alpha globulin glycoprotein that is a member of the serine proteinase inhibitor (serpin) family.

It inhibits the activity of certain enzymes called proteinases, such as cathepsin G that is found in neutrophils, and chymases found in mast cells, by cleaving them into a different shape or conformation. This activity protects some tissues, such as the lower respiratory tract, from damage caused by proteolytic enzymes.

Alpha 1-antichymotrypsin is also associated with the pathogenesis of Alzheimer's disease as it enhances the formation of amyloid-fibrils in this disease.

This enzyme is produced in the liver, and is an acute phase protein that is induced during inflammation.