Azurocidin/CAP37/HBP: Proteins and Enzymes

Azurocidin, also known as cationic antimicrobial protein 37 (CAP37) and heparin-binding protein (HBP), is found in the specialized azurophilic granules of neutrophils that also contain Cathepsin G, elastase and proteinase 3. Structurally similar to these serine proteases, Azurocidin lacks protease activity due to mutations in the catalytic triad. It possesses antibacterial activity through its binding to Gram-negative bacterial lipid A. As a modulator of endothelial permeability, Azurocidin acts in a paracrine fashion on endothelial cells causing the development of intercellular gaps and allowing leukocyte extravasation.