anti-α1-Antitrypsin, mAb (48D2)

α1-antitrypsin, 52kDa, is the prototypic member of the serine protease inhibitor (serpin) superfamily, which have a major role in inactivating neutrophil elastase and other proteases to maintain protease-antiprotease balance. The protein is synthesized mainly in the liver, but exerts its main function in the lung where it inhibits a variety of serine proteases, but primarily neutrophil elastase. It provides more than 90% of the antiproteolytic shield of the lower respiratory tract protecting the elastic tissue from degradation. Disorders of the enzyme include α 1-antitrypsin deficiency, a hereditary disorder in which lack of α 1-antitrypsin leads to uninhibited tissue breakdown during inflammation. This causes pulmonary emphysema and leads to liver cirrhosis in severe cases. Inhibitor of serine proteases. Its primary target is elastase, but it also has a moderate affinity for plasmin and thrombin. Irreversibly inhibits trypsin, chymotrypsin and plasminogen activator. The aberrant form inhibits insulin-induced NO synthesis in platelets, decreases coagulation time and has proteolytic activity against insulin and plasmin. Short peptide from AAT (SPAAT) is a reversible chymotrypsin inhibitor. It also inhibits elastase, but not trypsin. Its major physiological function is the protection of the lower respiratory tract against proteolytic destruction by human leukocyte elastase (HLE).