Receptor Occupancy at Equilibrium.
LakhaniVinal
C. ElstonTimothy
2017
<p><b>(A)</b> Simulation results for the number of active receptors as a function of time. Each color represents a different realization of the process. The thick, solid, black line is the mean from the data (5035 Ste2*). The thin, solid, black lines represent one standard deviation away from the mean, as calculated from the data (±52 Ste2*). The thick, dashed, black line is the theoretical mean calculated from <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1005386#pcbi.1005386.e003" target="_blank">Eq 1a</a> (5027 Ste2*). The thin, dashed, black lines are one theoretical standard deviation from the mean as calculated from <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1005386#pcbi.1005386.e004" target="_blank">Eq 1b</a> (±50 Ste2*). <b>(B)</b> A histogram of the data in <b>(A)</b>. The vertical lines are equivalent to those in <b>(A)</b>. The red curve shows the theoretical distribution. <b>(C)</b> A plot of time-averaged receptor occupancy. Each time point displays the average occupancy of the preceding 10 minutes. No average is available for t < 10min. The black lines are similar to those in <b>(A)</b>. The simulation mean is 5034 ± 23 Ste2*, and the theoretical mean is 5027 ± 19 Ste2*. The theoretical mean is again calculated with <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1005386#pcbi.1005386.e003" target="_blank">Eq 1a</a>, but the time-averaged standard deviation is calculated from <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1005386#pcbi.1005386.e013" target="_blank">Eq 5</a> and the relation described in the text. <b>(D)</b> A histogram of the data in <b>(C)</b>. The time-averaged distribution is much narrower (σ = 23 Ste2*) than the instantaneous distribution (σ = 52 Ste2*). The parameters used for these simulations are reported in <b><a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1005386#pcbi.1005386.t001" target="_blank">Table 1</a></b>, with binding and unbinding rates of 1.6×10<sup>6</sup> (M·s)<sup>-1</sup> and 0.011 s<sup>-1</sup>, respectively, and no ligand gradient.</p>