Serpin B1 Protein, Pig (His, Myc)

The Leukocyte elastase inhibitor/SERPINB1 protein, a neutrophil serine protease inhibitor, is pivotal in regulating the innate immune response, inflammation, and cellular homeostasis. Its primary function is to shield the cell from proteases released in the cytoplasm during stress or infection, preventing potential harm caused by the potent enzymes released from granules. SERPINB1 effectively regulates neutrophil proteases, including elastase, cathepsin G, proteinase-3, chymase, chymotrypsin, and kallikrein-3. Furthermore, it acts as a potent intracellular inhibitor of GZMH, directly impeding its proteolytic activity. During inflammation, SERPINB1 curtails the activity of inflammatory caspases (CASP1, CASP4, and CASP5) by inhibiting their caspase-recruitment domain (CARD) oligomerization and enzymatic activation. When secreted, SERPINB1 promotes beta-cell proliferation through its protease inhibitory function. It may undergo cleavage, resulting in a loss of anti-protease activity and the emergence of an endonuclease activity, though no specific catalytic site has been identified.