Quantifying cooperative multisite binding in the hub protein LC8 through Bayesian inference
Fig 7
Strong dependence of posterior distributions on model parameters.
(a,b) Graphical depiction of enthalpy uncertainty on a grid of ΔΔG and ΔG values, generated from the Bayesian posterior for each grid point based on synthetic data (with fixed ΔH = -10, ΔΔH = -1.5 kcal/mol). Boxes are colored by the width of the 95% credibility region for ΔH (a) and ΔΔH (b), with lighter colors corresponding to wider credibility regions (color bars). Red polygons demonstrate where each Kd (Kd1 for left, Kd2 for right) is greater than 17 μM, which is the cell concentration set for these synthetic isotherms. Black symbols indicate mean values for experimental isotherms for binding for BSN motif I (star) and SLC9A2 (octagon), for comparison. (c) Isotherms for binding between LC8 and SLC9A2 (top) and BSN I (bottom). C values for each step of binding, based on mean values taken from the posterior distribution are shown. (d) Synthetic isotherms designed to mimic BSN 1 (ΔG = -5.1, ΔΔG = -1.7, ΔH = -11, ΔΔH = -2), simulated at cell concentrations of 17 (orange) and 70 (purple) μM (syringe concentrations at 900 and 2000 μM respectively). (e,f) One-dimensional probability distributions for binding enthalpy (e) and change in enthalpy (f) for the isotherms in panel (d). (g,h) Two-dimensional marginal distributions (plotting ΔH against ΔΔH for isotherms in panel (d)). Isotherms at 17 μM in (g) and 70 μM in (h). Dimension widths are fixed for both plots for better comparison.