Human Alpha-1-Antichymotrypsin (SERPINA3) Protein

Background

SERPINA3, also known as alpha-1 antichymotrypsin (ACT), is a member of the serine protease inhibitor (serpin) superfamily. The SERPINA3 gene is located on chromosome 14 (14q32.13), in close proximity to other serpin genes, including SERPINA1, which encodes alpha-1 antitrypsin. SERPINA3 plays a crucial role in inhibiting the activity of certain proteases, particularly cathepsin G and chymotrypsin, enzymes involved in inflammation and immune responses. The protein encoded by SERPINA3 is predominantly synthesized in the liver, but it is also expressed in various other tissues, including the brain, lungs, and immune cells. SERPINA3 has been implicated in a variety of physiological and pathological processes, such as inflammation, tissue remodeling, and the acute phase response. It is also known for its association with neurodegenerative diseases, particularly Alzheimer's disease, where it is found in amyloid plaques.