AROMATIC R1 ESTER R2 ESTER R3 AMINE R4 ALIPHATIC R5 Res. #   Res. #   Res. #   Res. #   Res. #   TYR 15 27.8 TRP 5 50.0 TYR 7 36.8 TYR 24 72.7 TYR 13 43.3 GLN 7 13.0 HIS 2 20.0 TRP 5 26.3 TRP 6 18.2 TRP 8 26.7 GLU 6 11.1 ARG 2 20.0 ILE 3 15.8 ASP 2 6.1 HIS 4 13.3 LEU 5 9.3 SER 1 10.0 PRO 1 5.3 HIS 1 3.0 PHE 4 13.3 TRP 5 9.3       GLY 1 5.3       LEU 1 3.3 PRO 4 7.4       VAL 1 5.3             CYS 3 5.6       SER 1 5.3             ILE 3 5.6                         ALA 2 3.7                         PHE 2 3.7                         ARG 1 1.9                         VAL 1 1.9

Table 1: The interaction of cocaine molecule with amino acid residues in the 4 biological complexes. In bold-italic the aminoacids selected for generating the first 768 pentapeptides library. Res.=amino acid residue; #=number of contacts; %=percent of contacts in cocaine region.