Figure 5.
Shown are the observed experimental standard deviations of the 28 φ-values reported here as a function of the mean observed ΔΔGU for each of the three analysis methods we have employed. To illustrate the differences in φ-value variability that result from the three different estimation approaches, a line using a scatter-plot smoother was added. For both the nonzero and the fixed-m approach, the standard deviation of the φ-values among the three laboratories drops below the arbitrarily chosen line at 0.2 at a value of ΔΔGU of ~5 kJ/mol, while for the approach using extrapolation to zero denaturant, this value is ~7.5 kJ/ mol. The “x” symbols on the upper axis denote estimates that lie above σ = 2.