The sequence (Accession # 1EUB_A) corresponding to the catalytic domain (aa 104-274 aa) of human MMP-13 was expressed with 6-his tags in E. coli. The molecular weight of the recombinant Human MMP-13 catalytic Domain is 20.5 kDa. Its activity can be measured in FRET-based enzymatic assays (AnaSpec Cat# AS-71135, AS-71156). 10-20 ng of the enzyme is sufficient for FRET-based assay. MMP-13 is stored in 0.1M Tris, pH 7.5, 0.1M NaCl, 10 mM CaCl2, 0.05% Brij 35, 2mM sodium azide, 1 mg/mL BSA.