CHEMBL3706053

Enzymatic Assay: The cytidine deaminase (CDA) enzymatic assay described by Cacciamani, T. et al., Arch. Biochem. Biophys. 1991, 290, 285-92; Cohen R. et al., J. Biol. Chem., 1971, 246, 7566-8; and Vincenzetti S. et al., Protein Expr. Purif. 1996, 8, 247-53 was used to determine the inhibitory activity (IC50) of compounds described herein. Using this assay, the IC50 of these compounds was determined by following the decrease of substrate (cytidine) caused by the deamination reaction catalyzed by CDA. Disappearance of substrate (cytidine) over time was monitored by the absorbance at 280 nm of the reaction. The assay reaction was carried out in potassium phosphate buffer (pH 7.4, 20 mM, containing 1 mM DTT) in a total volume of 100 ul in a 96-well plate format. The final reaction mixture contained cytidine (50 uM) and purified human recombinant CDA. Purified enzyme was diluted so as to produce an absorbance change of approximately 2 milli-absorbance units/minute.