MW: 10,717 Da. Purity >99.0%. Description: Human Alpha-1 AntiChymotrypsin produced from normal human serum having a molecular mass of 68kDa.Introduction: Alpha 1 ACT is an early-stage acute-phase plasma protein and a serpin that preferentially inactivates chymotrypsin, cathepsin G, and chymase. Alpha-1- ACT, a serine protease inhibitor, is tightly associated with amyloid plaques in Alzheimer's disease (AD) and in normal aged human and monkey brain.Regulation of the serine p