FIGURE 4.

Sensitivity analysis for the pair of 2-state channels (C: closed ↔ O: open; opening rate: 2 ms^–1; closing rate: 1 ms^–1). The free energy of every composite state and barrier (labels on the left) was individually varied by an amount going from –2 kT to +2 kT. Then, the influence of this variation was quantified by the regression slope of the natural logarithm of observable parameters (labels on the top) and the r² value of this regression (scale rectangle in the top left corner). Positive correlations are shown as green bars above the horizontal lines. Negative correlations are shown as red bars below the horizontal lines. Color intensity corresponds to the slope and color saturation to r². The observable parameters were obtained from deterministic simulations, except the latencies, which were obtained from 1000 stochastic simulations (sweeps). As initial condition, all the channel pairs were placed in the CC state. For this analysis, p₁ and p₂ from the deterministic simulations were used instead of f₁ and f₂ obtained from the n = 1000 sweeps. While this figure summarizes the results using the regression slope and r², explicit plots of the natural logarithms of each marker vs. the energy change for every compound state and barrier can be generated by the MATLAB code deposited on Zenodo.