Quantifying cooperative multisite binding in the hub protein LC8 through Bayesian inference
Fig 2
Exact degeneracy in binding isotherms.
Based on the scaling relations of Eq (3), for any set of ligand and total macromolecule concentrations (Xt, Mt), there are infinitely many alternative concentrations (e.g., filled circles) on a diagonal line in the ([Xt], [Mt]) plane which yield exactly equivalent isotherms (inset, isotherms for points 1, 2, and 3 are drawn in distinct colors but overlay exactly) for a fixed set of thermodynamic parameters. For any given point in parameter space, equivalent degenerate lines can be drawn in a radial manner (e.g. the two additional black lines), passing through the point and the origin. The plotted synthetic isotherms are for 1:1 binding, but analogous degeneracy also holds for multivalent binding—see text. Note that no fixed relationship among concentrations is assumed during Bayesian inference.