Sivelestat, neutrophil elastase inhibitor

Supplementary information

This supplementary information is collated from multiple sources and compiled automatically.

Proteinase 3 (PR3) also known as myeloblastin is a serine protease enzyme that shares many functions with neutrophil elastase. It holds a molecular mass of approximately 29 kDa. PR3 is expressed in neutrophils a type of white blood cell involved in immune response. Mechanically PR3 participates in breaking down proteins by cleaving peptide bonds. Especially notable is its elastase function closely tied to its role in immune processes. PR3 is stored in neutrophil granules released during inflammation or infection to degrade extracellular matrix proteins and bacterial peptides.

Biological function summary

PR3 impacts immune regulation and inflammation control. When activated neutrophils degranulate releasing PR3 along with neutrophil elastase. Although PR3 is not part of a larger complex it functions alongside other neutrophil enzymes. Neutrophil elastase a close relative in structure and function sometimes substitutes or complements PR3 activity. Both enzymes share structural similarities such as the elastase structure enabling specific substrate binding and activity modulation through elastase inhibitors which regulate their activity to protect surrounding tissues.

Pathways

PR3 operates predominantly in the inflammatory response and tissue remodeling pathways. PR3 and neutrophil elastase play critical roles in leukocyte extravasation and pathogen defense maintaining homeostasis when properly regulated. Listed in pathways it links with proteins such as cathepsin G and elastase inhibitors to execute its proteolytic functions. The interaction between these proteins influences how neutrophils and related immune cells react to external stimuli further affecting cellular signaling and tissue repair processes.

PR3 is closely associated with autoimmune conditions like Granulomatosis with polyangiitis and respiratory diseases. In these disorders dysregulation of neutrophil elastase activity leads to excessive tissue damage. PR3 autoantibodies can serve as diagnostic markers in such autoimmune diseases emphasizing its pathological significance. Elastase inhibitors influence the clinical outcome by potentially mitigating the protease-mediated tissue degradation suggesting therapeutic avenues targeting both PR3 and neutrophil elastase for disease management.