. 2015 Nov 14;53(2):1222–1229. doi: 10.1007/s13197-015-2091-x

Table 2.

Intermolecular interactions of the docked complexes between peptide 1, peptide 2, and the inhibitor K-26, and the active site residues of ACE. Ligand atoms are highlighted in bold letters. Similar interactions among the ligands of the common ACE residues are highlighted in the same style. Binding affinity of each complex calculated by the docking protocol is also indicated. OC = carbonyl, NH = amine/amide, OPO = phosphate, N+ = nitrogen positive charge, O- = oxygen negative charge

Compounds	Binding affinity (kcal/mol)	Protein-ligand interactions
Compounds	Binding affinity (kcal/mol)	Hydrogen bond	Electrostatic	Hydrophobic
K-26	−8.2	ALA356: OC ALA356: NH ASP358 : OC GLU384:OPO T Y R 5 2 3 : O P O	Zn ²⁺ : *OPO*	TRP357:pi-sigma HIS387 : pi-pi HIS410:pi-pi VAL518:pi-sigma
Peptide1	- 9.5	GLN281:OC(Glu3) GLU411:OH(Gly4) T Y R 5 2 3 : O H (Gly4) ALA356: NH (Gly7) TYR360:OC(Gly7) GLU403:NH(Arg9) GLY404:NH(Arg9)	GLU376:N ⁺ (Gly1) ASP453:N ⁺ (Pro2) GLU411:N ⁺ (Pro5) GLU403:N ⁺ (Arg9) ARG522:O ⁻ (Arg9) Zn ²⁺ : OH (Gly4)	HIS383:pi-sigma(Pro2) HIS387 : pi-sigma (Pro5) PHE570:pi-sigma(Arg9)
Peptide2	−9.3	GLU162:NH(Gly1) ASP377:NH(Gly1) CYS370:NH(Gly1) ALA354:OC(Gly1) LYS511:OC(Glu2) THR282:OH(Thr3) HIS353:NH(Gly7) ASN66:NH(Ala11) ARG124:OC(Ala12) TYR360:NH(Ala15) TYR394:NH(Arg18) ASP358 : NH (Arg18) TYR360:NH(Arg18)	GLU162:N ⁺ (Gly1) ASP377:N ⁺ (Gly1) LYS511:O ⁻ (Glu2) ASP358:N ⁺ (Arg18) Zn ²⁺ : OC (Ala6)	HIS383:pi-sigma(Pro5) HIS410:pi-cation (Arg18)