CHEMBL3707737

Enzymatic Assays: Type 2 DHODH activity was monitored with either the direct assay measuring the formation of orotate or via a chromogen reduction assay using DCIP. Although the extinction coefficient and absorption wavelength are preferable for the chromogen reduction assay, the inorganic electron acceptor DCIP can be utilized by DHODH as the final electron acceptor in lieu of CoQn when the endogenous substrate is at a low concentration. As such, the direct assay was used to measure the binding affinity of pfDHODH to CoQD and L-DHO. The enzymatic reaction was performed by varying the L-DHO concentration (1-400 μM) or CoQD concentration (1-200 μM) while keeping the other substrate constant and in excess. Inhibition of DHODH by small molecules was evaluated using the chromogen based assay with a final substrate concentration of 200 μM L-DHO, 18 μM CoQD, and 100 μM DCIP, unless otherwise noted.