Fig. 2

S100A5 can bind Ca²⁺ and Cu²⁺ simultaneously without antagonism. Plots show integrated data and global Bayesian fits from replicate isothermal titration calorimetry experiments: (a) Cu²⁺ binding to apo protein, (b) Cu²⁺ binding to Ca²⁺-saturated protein, (c) Ca²⁺ binding to apo protein, and (d) Ca²⁺ binding to Cu²⁺-saturated protein. Points are integrated titration shots. Lines are 100 curves drawn from the posterior distribution of the MCMC samples. For Cu²⁺ binding experiments technical replicates are shown in blue and red. Ca²⁺ binding experiments were performed with fixed protein concentration and four different titrant/titrate ratios: 8X (blue), 10X (purple), 15X (red), and 18X (green). For clarity Y-axes display total heat per shot, so that curves from different titrant concentrations fall on different areas of the graph. Raw data corresponding to these integrated heats are displayed in Additional file 1: Figure S1