Fig. 3

Challenges to get from the concentration of inhibitor that gives 50 % of inhibition (IC₅₀) to the assay independent inhibitory potency (K _i) for a HAT inhibitor. In case of bi-substrate enzymes like HATs, many factors need to be considered when calculating the inhibitory potency from the IC₅₀. Kinetic studies combined with affinity studies, crystal structures, dead-end inhibitors, and studies on the catalytic mechanism of HATs aid in deriving a K _i for HAT inhibitors