... pattern. Amino acids withsimilar characteristics were grouped together as follows:aromatic amino acids (Phe, Tyr, and Trp); negativelycharged amino acids (Asp and Glu); positively charged amino acids ... pro-vided insights into important enzyme–substrate interac-tions. For example, molecular modeling of HCinteracting with angiotensin (Ang) I has led to conclu-sions regarding the S2¢ binding site of ... by an amino acid with an uncharged side chain, a preference formainly aliphatic amino acids was observed. However,a weak preference for acidic P2¢ amino acids stillremained for the two single...