Alpha 1-antichymotrypsin

{{Short description|Protein found in humans}} {{Infobox_gene}} '''Alpha 1-antichymotrypsin''' (symbol '''α<sub>1</sub>AC''',<ref name=loganabbrev /> '''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.

== Function ==

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.<ref name=kalsheker>{{cite journal |author=Kalsheker N |title=Alpha 1-antichymotrypsin |journal=Int. J. Biochem. Cell Biol. |volume=28 |issue=9 |pages=961–4 |year=1996 |pmid=8930118 |doi=10.1016/1357-2725(96)00032-5|s2cid=11230631 }}</ref>

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.<ref>{{cite web | title = Entrez Gene: SERPINA3 serpin peptidase inhibitor, clade A (alpha-1 antiproteinase, antitrypsin), member 3| url = https://www.ncbi.nlm.nih.gov/gene?Db=gene&Cmd=ShowDetailView&TermToSearch=12}}</ref>

Alpha 1-antichymotrypsin is also associated with the pathogenesis of Alzheimer's disease as it enhances the formation of amyloid-fibrils in this disease.<ref name=kalsheker/>

==Interactions==

Alpha 1-antichymotrypsin has been shown to interact with DNAJC1.<ref name="pmid14668352">{{cite journal |vauthors=Kroczynska B, Evangelista CM, Samant SS, Elguindi EC, Blond SY | title = 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 | journal = J. Biol. Chem. | volume = 279 | issue = 12 | pages = 11432–43 |date=March 2004 | pmid = 14668352 | pmc = 1553221 | doi = 10.1074/jbc.M310903200 | doi-access = free }}</ref>

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

==References== <references> * <ref name=loganabbrev>{{cite book|author1=Logan, Carolynn M.|author2=Rice, M. Katherine|title=Logan's Medical and Scientific Abbreviations|date=1987|publisher=J. B. Lippincott Company|location=Philadelphia|isbn=0-397-54589-4|page=[https://archive.org/details/logansmedicalsci00loga/page/3 3]|ref=logansaabrev|url-access=registration|url=https://archive.org/details/logansmedicalsci00loga/page/3}}</ref> </references>

==Further reading== {{refbegin | 2}} *{{cite journal |vauthors=Janciauskiene S, Wright HT |title=Inflammation, antichymotrypsin, and lipid metabolism: autogenic etiology of Alzheimer's disease. |journal=BioEssays |volume=20 |issue= 12 |pages= 1039–46 |year= 1999 |pmid= 10048303 |doi= 10.1002/(SICI)1521-1878(199812)20:12<1039::AID-BIES10>3.0.CO;2-Z }} *{{cite journal |vauthors=Kalsheker N, Morley S, Morgan K |title=Gene regulation of the serine proteinase inhibitors alpha1-antitrypsin and alpha1-antichymotrypsin. |journal=Biochem. Soc. Trans. |volume=30 |issue= 2 |pages= 93–8 |year= 2002 |pmid= 12023832 |doi= 10.1042/BST0300093 }} {{refend}}

==External links== * The MEROPS online database for peptidases and their inhibitors: [https://merops.sanger.ac.uk/cgi-bin/merops.cgi?id=I04.002 I04.002] * {{MeshName|Alpha+1-antichymotrypsin}} * {{UCSC gene info|SERPINA3}} * {{PDBe-KB2|P01011|Human Alpha-1-antichymotrypsin}}

Category:Acute-phase proteins