Background：

Elastases form a subfamily of serine proteases that hydrolyze many proteins in addition to elastin.Humans have six elastase genes which encode the structurally similar proteins.The product of this gene hydrolyzes proteins within specialized neutrophil lysosomes called azurophil granules as well as proteins of the extracellular matrix following the protein's release from activated neutrophils.The enzyme may play a role in degenerative and inflammatory diseases by its proteolysis of collagen-IV and elastin of the extracellular matrix.This protein degrades the outer membrane protein A (OmpA) of E.coli as well as the virulence factors of such bacteria as Shigella Salmonella and Yersinia.Mutations in this gene are associated with cyclic neutropenia and severe congenital neutropenia (SCN).This gene is clustered with other serine protease gene family members azurocidin 1 and proteinase 3 genes at chromosome 19pter.All 3 genes are expressed coordinately and their protein products are packaged together into azurophil