Azurocidin also known as cationic antimicrobial protein CAP37 or heparin-binding protein (HBP) is a
protein that in humans is encoded by the AZU1gene.[3][4]
Function
Azurophil granules, specialized
lysosomes of the
neutrophil, contain at least 10 proteins implicated in the killing of microorganisms. The protein encoded by this gene is an azurophil granule antimicrobial protein, with monocyte chemotactic and antibacterial activity. It is also an important multifunctional
inflammatory mediator.[5] The genes encoding this protein, neutrophil elastase 2, and proteinase 3 are in a cluster located at chromosome 19pter. All 3 genes are expressed coordinately and their protein products are packaged together into azurophil granules during neutrophil differentiation.[4]
Structure
This encoded protein is a member of the PA clan of proteases but it is not a serine proteinase, because the active site serine and histidine residues are replaced, making it a
pseudoenzyme.[6]
Clinical significance
In patients with fever, high plasma levels of HBP indicates that the patient is at high risk of developing
sepsis with
circulatory collapse.[7]
Morgan JG, Pereira HA, Sukiennicki T, et al. (1992). "Human Neutrophil Granule Cationic Protein CAP37 is a Specific Macrophage Chemotaxin that Shares Homology with Inflammatory Proteinases". Chemotactic Cytokines. Advances in Experimental Medicine and Biology. Vol. 305. pp. 89–96.
doi:
10.1007/978-1-4684-6009-4_11.
ISBN978-1-4684-6011-7.
PMID1755383.
Green BG, Weston H, Ashe BM, et al. (1991). "PMN elastases: a comparison of the specificity of human isozymes and the enzyme from other species toward substrates and inhibitors". Arch. Biochem. Biophys. 286 (1): 284–92.
doi:
10.1016/0003-9861(91)90042-H.
PMID1897955.
Flodgaard H, Ostergaard E, Bayne S, et al. (1991). "Covalent structure of two novel neutrophile leucocyte-derived proteins of porcine and human origin. Neutrophile elastase homologues with strong monocyte and fibroblast chemotactic activities". Eur. J. Biochem. 197 (2): 535–47.
doi:
10.1111/j.1432-1033.1991.tb15942.x.
PMID2026172.
Pereira HA, Spitznagel JK, Pohl J, et al. (1990). "CAP 37, a 37 kD human neutrophil granule cationic protein shares homology with inflammatory proteinases". Life Sci. 46 (3): 189–96.
doi:
10.1016/0024-3205(90)90104-Y.
PMID2406527.
Iversen LF, Kastrup JS, Bjørn SE, et al. (1997). "Structure of HBP, a multifunctional protein with a serine proteinase fold". Nat. Struct. Biol. 4 (4): 265–8.
doi:
10.1038/nsb0497-265.
PMID9095193.
S2CID19949043.
Lindmark A, Garwicz D, Rasmussen PB, et al. (1999). "Characterization of the biosynthesis, processing, and sorting of human HBP/CAP37/azurocidin". J. Leukoc. Biol. 66 (4): 634–43.
doi:
10.1002/jlb.66.4.634.
PMID10534120.
S2CID27897421.