OMNIMMP®RED fluorogenic substrate

TQ3-GABA-Pro-Cha-Abu-Smc-His-Ala-Dab (6′-TAMRA) -Ala-Lys-NH 2 [TQ3=quencher; GABA=4-aminobutyric acid; Cha=L-cyclohexylalanine; Abu=2-aminobutyric acid; Smc=S-methyl-L-cysteine; Dab=2,4-diaminobutyric acid; 6’-TAMRA=6’-tetramethylrhodamine]

Emission at the red 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 K m s for OMNIMMP® RED substrate are 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 s, OMNIMMP® RED is avidly cleaved by MMPs, with k cat / K m s in the range of 10 5 -10 7 M -1 sec -1 . The high k cat / K m s and the ultra-strong fluorescence of OMNIMMP® RED allow for substrate concentrations much lower than the K m , a condition generally desirable in inhibitor screening/kinetics assays. The following kinetic data [ k cat / K m (M -1 s -1) ; K m (μM) ] have been determined in-house. These are approximate only; customer should determine kinetics based on his/her assay conditions. MMP-1 (6.7x10 6 ; 0.48), MMP-2 (4.2x10 7 ; 0.38), MMP-3 (cleaves well; kinetics not yet determined), MMP-7 (1.6x10 7 ; 1.33), MMP-8 (1.6x10 7 ; 0.53), MMP-9 (2.3x10 7 ; 0.35), MMP-10 (cleaves well; kinetics not yet determined), MMP-11 (does not cleave), MMP-12 (cleaves well; kinetics not yet determined), MMP-13 (cleaves well; kinetics not yet determined), MMP-14 (cleaves well; kinetics not yet determined), MMP-19 (2.7x10 5 ; 0.50), MMP-20 (cleaves; kinetics not yet determined) .