plotted vs. for all of the mutants grouped according to the mutation site along the structure of Beta3s. The optimal regression line (including the wild-type data point) is plotted, and its slope, i.e., the multipoint Φ value, is reported in the lower right corner of each graph with the SD derived from the fit in parentheses. The correlation coefficient is 0.91, 0.67, 0.93, 0.86, 0.87, and 0.88 for W2, I3, W10, Y11, I18, and Y19 mutants, respectively.