Human MMP-9

Matrix metalloproteinases are a family of zinc and calcium-dependent endopeptidases which degrade extracellular matrix proteins. Matrix metalloproteinase 9 (MMP-9) is secreted as a 92-kDa zymogen that is cleaved into a 82-kDa active enzyme. MMP-9 has a gelatin-binding domain consisting of three fibronectin type II units, a catalytic domain containing the zinc-binding site, a proline-rich type V collagen-homologous domain and a hemopexin-like domain. MMP9 is produced by monocytes, macrophages, neutrophils, keratinocytes, fibroblasts, osteoclasts and endothelial cells, and is involved in inflammatory responses, tissue remodeling, wound healing, tumour growth and metastasis. Defects in MMP-9 are the cause of metaphyseal anadysplasia type 2, an abnormal bone development characterized by severe skeletal changes that resolve spontaneously with age. Recombinant human MMP-9 comprises a 338 aa fragment (113-450) corresponding to the catalytic domain of the protein and is expressed in E. coli with an amino-terminal hexahistidine tag.