SERPINE2 Antibody / PN-1 / Protease nexin 1

SERPINE2 antibody detects Serpin family E member 2, also known as protease nexin-1, a secreted glycoprotein that inhibits a range of serine proteases including thrombin, trypsin, plasmin, and urokinase-type plasminogen activator. Encoded by the SERPINE2 gene on chromosome 2q33.3, this protein belongs to the serpin superfamily of suicide inhibitors that regulate extracellular proteolysis in tissue remodeling, coagulation, inflammation, and neuroprotection. The reactive center loop of SERPINE2 serves as the protease recognition site; cleavage triggers a conformational rearrangement that traps the protease, forming a stable inactive complex. Through this mechanism, SERPINE2 maintains extracellular matrix integrity and limits tissue damage during injury or inflammation.

SERPINE2 is widely expressed in the brain, lung, vascular endothelium, and reproductive organs. In the central nervous system, it is secreted by neurons and glial cells and contributes to neuronal survival by restricting plasmin activity and supporting synaptic stability. In the vasculature, SERPINE2 modulates thrombin signaling and vascular remodeling, balancing coagulation and fibrinolysis. Genetic studies in animal models demonstrate that loss of SERPINE2 results in perinatal lethality and vascular abnormalities, highlighting its essential role in development and homeostasis.

The SERPINE2 antibody is utilized in neurobiology, vascular biology, and cancer research to evaluate protease regulation and tissue remodeling. Western blotting reveals a 45 kilodalton band representing the mature glycosylated protein, while immunohistochemistry shows extracellular and pericellular staining consistent with its secretory nature. In the nervous system, SERPINE2 expression is induced following injury and ischemia, suggesting a protective role against excitotoxic and proteolytic damage. In cancer, its expression pattern varies depending on tumor type: elevated levels have been observed in gliomas and pancreatic cancer, where SERPINE2 supports tumor invasion and angiogenesis, while downregulation in other malignancies correlates with increased protease activity and metastasis.

Functionally, SERPINE2 interacts with extracellular matrix components such as heparan sulfate and collagen, anchoring it near protease release sites. It also binds to low-density lipoprotein receptor-related protein 1 (LRP1) to mediate endocytosis of protease-inhibitor complexes. The SERPINE2 antibody allows visualization of these interactions and quantification of expression under physiological and pathological conditions. Because protease regulation is critical for tissue repair, clot formation, and neural maintenance, this antibody is a valuable tool for mechanistic and translational studies.