Figure 4. Modulation of dynamics by substrate and inhibitor binding.

a, SmFRET traces obtained in the presence of 2 mM Na⁺ and increasing Asp concentrations. b, The apparent durations of the dynamic (black) and quiescent (red) periods as a function of Asp concentration. Shown are averages and standard deviations for 3 independent datasets containing at least 250 molecules each. c, A smFRET trace obtained in the presence of 200 mM Na⁺ and 100 μM Asp. Expanded views of the flicker events (shaded in pink) are shown below the trace. d, Survival plot of the observed flickers. Solid line is a fit to a single exponential decay. e, Transition density plots for flicker events in saturating Asp (left) or TBOA (right). Average transition frequencies are ∼ 0.02 s⁻¹ and < 0.005 s⁻¹, respectively. Data in panels d and e were collected with 400 ms integration time.