Figure 4. Inhibition kinetics.
(A), Measurement of the specific activity of CoaE as a function of enzyme concentration. Freshly prepared CoaE was diluted in buffer alone or was pre-saturated with 1 mM CTP and diluted in buffer+CTP to a range of concentrations (10 nM–10 µM) and activity was measured at 0.5 mM DCoA. (B), Dixon plot (1/V vs. [CTP]) illustrating the inhibition of the mycobacterial dephosphocoenzyme A kinase by CTP (Ki = 34 µM), at three different concentrations of the leading substrate, DCoA.