Serpin family B member 1 (SERPINB1)

Serpin family B member 1 (SERPINB1) is an intracellular serine protease inhibitor of the clade B serpin family, best known as the leukocyte elastase inhibitor or monocyte/neutrophil elastase inhibitor. It is highly expressed in neutrophils and other immune cells, where it inhibits neutrophil serine proteases such as elastase, cathepsin G, and proteinase 3, protecting cells and tissues from the destructive effects of these enzymes released during inflammation or stress. SERPINB1 plays an important role in regulating the survival and function of mature neutrophils and ensures the maintenance of the neutrophil reserve during immune responses by opposing protease-driven cell death. Its functions extend beyond innate immunity to involvement in wound healing, cell migration, and possibly the modulation of tumor cell aggressiveness in certain malignancies. There are no current drugs directly targeting SERPINB1, but its levels or functional activity may serve as useful biomarkers in inflammatory diseases and cancer.

Other names

Leukocyte elastase inhibitorLEIMonocyte/neutrophil elastase inhibitorELANH2MNEIPI-2PI2EIHEL-S-27HEL57epididymis luminal protein 57epididymis secretory protein Li 27peptidase inhibitor 2protease inhibitor 2 (anti-elastase)

Inhibition of serine protease activity (e.g., neutrophil elastase, cathepsin G, proteinase 3) through a suicide-substrate (stressed-to-relaxed) conformational mechanism; limits excessive proteolytic damage and regulates downstream inflammatory signaling and cell survival