MMP-3 fluorogenic substrate

This substrate offers key advantages over other MMP-3 substrates. Emission at the green end of the spectrum avoids the interference at lower wavelengths often exhibited by screening compounds, and by substances commonly found in biological samples and tissue culture medium. MMP substrate peptides display poor aqueous solubility, often with K m s near or above their limits of solubility, making enzyme and inhibitor kinetics difficult. MMP-3 K m (~0.64μM) for this substrate is below its solubility limit (~2μM in assay buffer), allowing for substrate concentrations higher than the K m , a condition generally desirable in endpoint assays. In addition to the efficient binding as exhibited by low K m , this substrate is avidly cleaved by MMP-3, with a k cat / K m of ~6.5 x 10 7 M -1 sec -1 . The high k cat / K m and the ultra-strong fluorescence of this substrate allow for substrate concentrations much lower than the K m , a condition generally desirable in inhibitor screening/kinetics assays.