Assay development and inhibition of the -DprE2 essential reductase from .

DprE2 is an essential enzyme in the synthesis of decaprenylphosphoryl-β-d-arabinofuranose (DPA) and subsequently arabinogalactan, and is a significant new drug target for . Two compounds from the GSK-177 box set, GSK301A and GSK032A, were identified through -DprE2-target overexpression studies. The -DprE1-DprE2 complex was co-purified and a new DprE2 assay developed, based on the oxidation of the reduced nicotinamide adenine dinucleotide cofactor of DprE2 (NADH/NADPH). The -DprE1-DprE2 complex showed interesting kinetics in both the DprE1 resazurin-based assay, where -DprE2 was found to enhance -DprE1 activity and reduce substrate inhibition; and also in the DprE2 assay, which similarly exhibited substrate inhibition and a difference in kinetics of the two potential cofactors, NADH and NADPH. Although, no inhibition was observed in the DprE2 assay by the two GSK set compounds, spontaneous mutant generation indicated a possible explanation in the form of a pro-drug activation pathway, involving and .