Assay Method Information

Assay Name:  Biochemical Assay
Description:  IC50 values of test compounds were determined with an enzyme activity assay using the C-domain of MALT1 (amino acids 329-824). The readout parameter is the increase of fluorescence lifetime over time, proportional to enzyme activity.The assay employs a short peptide substrate labeled with the single fluorophore PT14 as a fluorescence lifetime probe sensitive to the cleavage state of the substrate (PT14: 6-(9-oxo-9H-acridin-10-yl)-hexanoate, AssayMetrics, UK). The peptide substrate has the following sequence: Ac-Trp-Leu-Arg-Ser-Arg^Cys(PT14)-NH2 (Product number BS-9117, Biosyntan, Germany, N-terminus to C-terminus from left to right in three letter code, Ac: acetyl group, Cys(PT14): cysteine residue with the fluorophore PT14 conjugated to the cysteine sulfhydryl group via a maleimide group; C-terminus of the peptide is amidated; within the substrate sequence written above, ^ indicates the scissile bond). The assay buffer consists of 200 mM Tris/HCl at pH 7.5, 0.8 M Na citrate, 100 μM EGTA, 100 μM DTT and 0.05% (w/v) CHAPS. The kinetic characterization of the enzymatic reaction led to the determination of a Michaelis Constant (KM) of 40 μM and a kcat value of 34 s−1. The assay was established for the 384-well plate format using black microtiter round well plates (Product number 95040020, Thermo Electron Oy, Finland). Test compounds were dissolved in 100% (v/v) DMSO or a mixture containing 90% (v/v) DMSO and 10% (v/v) H2O at a stock concentration of 100 mM. Serial dilutions of test compounds were prepared using either 100% (v/v) DMSO or a mixture containing 90% (v/v) DMSO and 10% (v/v) H2O.
Affinity data for this assay
 

If you find an error in this entry please send us an E-mail