Alpha 1-Antichymotrypsin, a member of the serine proteinase inhibitor (serpin) family, inhibits neutrophil proteinase cathepsin G and mast cell chymases, and protects the lower respiratory tract from damage by proteolytic enzymes. It contains a reactive centre loop, which interacts with cognate proteinases, resulting in loop cleavage and a major conformational change. Recently, alpha 1-antichymotrypsin has been identified as a major constituent of the neurofibrillary plaques associated with Alzheimers disease, and in vitro studies have shown that it enhances the rate of amyloid-fibril formation. These observations and recent genetic evidence suggest that alpha 1-antichymotrypsin is important in the pathogenesis of Alzheimers disease.
基因名
SERPINA3
蛋白名
alpha-1-antichymotrypsin
亚基
Interacts with DNAJC1.
亚细胞定位
Secreted.
组织特异性
Plasma. Synthesized in the liver. Like the related alpha-1-antitrypsin, its concentration increases in the acute phase of inflammation or infection. Found in the amyloid plaques from the hippocampus of Alzheimer disease brains.
相似性
Belongs to the serpin family.
功能
Although its physiological function is unclear, it can inhibit neutrophil cathepsin G and mast cell chymase, both of which can convert angiotensin-1 to the active angiotensin-2.