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## Figure 2.
Analysis of typical FRET data recovers true values of K. A typical three-cube FRET experiment is simulated from three virtual cells, each
containing the indicated concentrations of donor- and acceptor- tagged proteins (A,
left). The data is summarized in bar graphs with mean ± SD (A, right). Ten measurements/channel
are made for each cell with 5% added measurement noise. For other parameters, see
Methods. The data was analyzed in two ways to find the values of _{d }and E_{fr}Kand _{d }Econsistent with the data. We first calculated the energy for an array of parameter
values; as the energy contour plot shows (B), the energy was minimal near the true
parameter values. We also used a Monte Carlo algorithm to explore _{fr }K-_{d}Espace, running 3 biased random walks starting from different initial positions (white
*) and running for 12,000 steps. The paths of the walks (for clarity only the first
2,000 steps are shown) are superimposed on the contour plot (B) and all three converged
to a region around the true value which coincides with the energy minimum. Histograms
of the locations visited by all three walks, including only post-convergence steps
(11,000 steps are included from each walk) act as approximate posterior distributions
for _{fr }Kand _{d }E(C). The dashed red lines indicate the true values of _{fr }Kand _{d }Eused to generate the data.
_{fr }Lichten and Swain |