Alpha 1-antichymotrypsin

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Template:Infobox gene Alpha 1-antichymotrypsin (symbol α1AC,[1] A1AC, or a1ACT) is an alpha globulin glycoprotein that is a member of the serpin superfamily. In humans, it is encoded by the SERPINA3 gene.


Alpha 1-antichymotrypsin inhibits the activity of certain enzymes called proteases, 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.[2]

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

Clinical significance

Deficiency of this protein has been associated with liver disease. Mutations have been identified in patients with Parkinson disease and chronic obstructive pulmonary disease.[3]

Alpha 1-antichymotrypsin is also associated with the pathogenesis of Alzheimer's disease as it enhances the formation of amyloid-fibrils in this disease.[2]


Alpha 1-antichymotrypsin has been shown to interact with DNAJC1.[4]

See also

  • Alpha-1 antitrypsin, another serpin that is analogous for protecting the body from excessive effects of its own inflammatory proteases


  1. Logan, Carolynn M.; Rice, M. Katherine (1987). Logan's Medical and Scientific Abbreviations. Philadelphia: J. B. Lippincott Company. p. 3. ISBN 0-397-54589-4. 
  2. 2.0 2.1 Kalsheker N (1996). "Alpha 1-antichymotrypsin". Int. J. Biochem. Cell Biol. 28 (9): 961–4. PMID 8930118. doi:10.1016/1357-2725(96)00032-5. 
  3. "Entrez Gene: SERPINA3 serpin peptidase inhibitor, clade A (alpha-1 antiproteinase, antitrypsin), member 3". 
  4. Kroczynska B, Evangelista CM, Samant SS, Elguindi EC, Blond SY (March 2004). "The SANT2 domain of the murine tumor cell DnaJ-like protein 1 human homologue interacts with alpha1-antichymotrypsin and kinetically interferes with its serpin inhibitory activity". J. Biol. Chem. 279 (12): 11432–43. PMC 1553221Freely accessible. PMID 14668352. doi:10.1074/jbc.M310903200. 

Further reading

External links

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