FIGURE 3.

An MDS projection of the AA’s property space spanned by the seven selected physicochemical properties. The distance between any pair of letters corresponds to the physicochemical similarity between respective amino acids. The figure shows the ability to discern any pair of amino acids using selected physicochemical properties. The more similar amino acids, the smaller the distance between them, e.g., Ile (I) and Leu (L). Likewise, amino acids with similar physicochemical properties like basic Lys (K), Arg (R), and His (H) form distinct groups.