Figure 3.

Simulated MMP1 interdomain dynamics as a Poisson process. (A) Examples of simulated two-state FRET trajectories with noise for active (blue) and inactive (orange) MMP1. (B) Histograms of simulated FRET values. (C) Autocorrelations of simulated trajectories recover the sum, k1 + k2, from exponential fits (active: dashed black line; inactive: solid black line). As expected, the power law does not fit autocorrelations (active: dashed red line; inactive: solid green line). Exponential fits recover k1 + k2 with and without noise. The addition of noise changes the width of the FRET histograms and y-intercepts. The error bars are the SEs for histograms and autocorrelations and are too small to be seen. The Supporting Materials and Methods contain the best-fit parameters for histograms (Table S4) and autocorrelations (Table S5). To see this figure in color, go online.