Figure 5. Metal-mediated “interaction saturation” of FLK11 in the catalytic groove of exo-β-(1,3)-glucanase. Surface representation of C. albicans exo-β-(1,3)-glucanase (green) with electrostatic potential mapped (red = anionic, blue = cationic). (A) Uncomplexed FLK11 bound within the catalytic groove, showing partial occupancy of the negatively charged channel and limited penetration toward the catalytic residues. (B) FLK11–Cu²⁺ complex bound in the same pocket, in which metal coordination rigidifies the peptide and positions a cationic side chain deeper into the anionic groove, resulting in enhanced electrostatic complementarity and increased hydrogen-bonding and salt-bridge contacts (“interaction saturation”). The Cu²⁺ ion is shown as an orange sphere; peptides are rendered as sticks : Docking-Based Evaluation of Defensin-Derived Peptides and Their Cu²⁺ Complexes as Dual-Target Inhibitors of Exo-β-(1,3)-Glucanase and Penicillin-Binding Protein Transglycosidase 1B : Science and Education Publishing

Figure 5. Metal-mediated “interaction saturation” of FLK11 in the catalytic groove of exo-β-(1,3)-glucanase. Surface representation of C. albicans exo-β-(1,3)-glucanase (green) with electrostatic potential mapped (red = anionic, blue = cationic). (A) Uncomplexed FLK11 bound within the catalytic groove, showing partial occupancy of the negatively charged channel and limited penetration toward the catalytic residues. (B) FLK11–Cu²⁺ complex bound in the same pocket, in which metal coordination rigidifies the peptide and positions a cationic side chain deeper into the anionic groove, resulting in enhanced electrostatic complementarity and increased hydrogen-bonding and salt-bridge contacts (“interaction saturation”). The Cu²⁺ ion is shown as an orange sphere; peptides are rendered as sticks

American Journal of Pharmacological Sciences. 2026, 14(1), 7-19 doi:10.12691/ajps-14-1-2