The efficient expression of human fibroblast collagenase in Escherichia coli and the discovery of flavonoid inhibitors

Human skin fibroblast collagenase also known as Matrix Metalloproteinase-1 (MMP-1) is a key enzyme in remodeling and degradation of extracellular matrix, and the inhibitors of human MMP-1 are effective drug candidates for the treatment of cancer. In this study, we report an improved method for high-level expression of soluble human MMP-1 catalytic domain (cd-MMP-1) in E. coli. The enzymatic activity is found maximum at pH 7.5 and temperature 40 degrees C with a K-m value of 13.02 mu M. Effects of 17 structure-related flavonoids on MMP-1 activity are evaluated using a fluorescent assay, 6 inhibitors are identified with IC50 < 10 mu M. Fisetin is the most active agent with an IC50 value of 1.35 mu M and is identified as a mixed type inhibitor. Our improved soluble cd-MMP-1 expression method provides a basis for inhibitors identification and may be beneficial to discover novel anti-cancer agent targeting human MMP-1.