Chemical. CAS 197890-44-1. Formula C19H31N3O4S . HCl. MW 397.5 . 36.5. Potent, selective intracellular neutrophil elastase NE, alpha-1-proteinase inhibitor by covalently binding to NE. Inhibits human neutrophil elastase HNE and is selective over other human serine proteases with IC50 values of 22nM for HNE, >100µM for trypsin, cathepsin G and plasmin, >3µM for chymotrypsin and tissue plasminogen activator. Specific beta-cell proliferation promoter. Similar to SerpinB1, which functions through its inhibiting activity of several proteases including neutrophil elastase, cathepsin G and proteinase-3. Reverses insulin resistance and body weight gain in HFD-fed mice, suggesting that the SerpinA1-NE system regulates AMPK signaling, fatty acid oxidation FAO and energy expenditure. The imbalance between SerpinA1 alpha1-antitrypsin A1AT and neutrophil elastase NE contributes to the development of obesity and related inflammation, insulin resistance and liver steatosis.