Fig. 8

Distance of amino acid value in hydrophobicity scales. a Calculated was absolute difference between the values of two amino acids for the best performing evolutionary derived scale (first box), of scale 14 (highest S value, second box) and of scale 40 (lowest S value, third box) after normalization of the scales to (X-min)/(max–min). Green boxes mark distances below 0.1, dark green boxes below 0.01, red boxes distance above 0.9 and dark red boxes distance above 0.99. Combination framed in orange mark amino acids for which values should be rather similar as concluded from the low difference in the best performing and the evolutionary evolved scale, blue frames mark amino acid combinations for which values should be rather different as concluded from the low difference in the best performing and the evolutionary evolved scale and yellow frames mark amino acid combination for which the value difference is irrelevant. b The clusters with comparable (black lines) or distinct amino acids values (blue lines) are shown. c The arrow indicates the distance of amino acid values that should be present in a good performing scale