Recombinant Human PRTN3 protein

PRTN3 (proteinase 3) is a serine protease primarily expressed in neutrophil granulocytes, where it is stored in azurophilic granules and plays a role in innate immunity by degrading microbial pathogens and modulating inflammatory responses. It is also known as myeloblastin due to its initial identification in myeloid cells. PRTN3 gained clinical significance as a major autoantigen in ANCA-associated vasculitides (AAV), particularly granulomatosis with polyangiitis (GPA). In these autoimmune disorders, autoantibodies targeting PRTN3 (c-ANCA) contribute to vascular inflammation and tissue damage through neutrophil activation and dysregulated protease activity.

The recombinant PRTN3 protein is engineered to mimic the native structure and function of the enzyme for research and diagnostic applications. Produced using expression systems like *E. coli* or mammalian cells, it retains key epitopes for antibody recognition while avoiding contaminants from native sources. Recombinant PRTN3 is crucial for developing ELISA-based assays to detect anti-PRTN3 antibodies in patient sera, aiding AAV diagnosis and disease monitoring. It also facilitates mechanistic studies on neutrophil biology, protease-substrate interactions, and ANCA-mediated pathogenic pathways. Additionally, this tool supports drug discovery efforts targeting PRTN3 activity in inflammatory diseases. Recent studies further explore its potential role in cancer biology, given its overexpression in certain leukemias. Despite its utility, challenges remain in replicating post-translational modifications critical for specific functional studies, prompting ongoing optimization of recombinant production platforms.