The adsorption behavior of the amino acid, glycine (Gly), via the carboxyl, hydroxyl, and amino groups onto the surfaces of AlN and AlN fullerene-like cages were computationally evaluated by the combination of density functional theory (DFT) and molecular docking studies. It was found that Gly can chemically bond with the AlN and AlN fullerene-like cages as its amino group being more favorable to interact with the aluminum atoms of the adsorbents compared to carboxyl and hydroxyl groups. Oxygen and carbon doping were reported to reduce steric hindrance for Glycine interaction at Al site of AlON/Gly and AlCN/Gly complexes. Interaction was further enhanced by oxygen doping due to its greater electron withdrawing effect. Herein, the AlON/Gly complex where two carbonyl groups of Gly are bonded to the aluminum atoms of the AlN fullerene-like cage is the most stable interaction configuration showing ∆H and ∆G values of -81.74 kcal/mol and -66.21 kcal/mol, respectively. Computational studies also revealed the frequency shifts that occurred due to the interaction process. Molecular docking analysis revealed that the AlN/Gly (-11.7 kcal/mol) and the AlON/Gly (-9.2 kcal/mol) complexes have a good binding affinity with protein tumor necrosis factor alpha (TNF-α). TNF-α was implicated as a key cytokine in various diseases, and it has been a validated therapeutic target for the treatment of rheumatoid arthritis. These results suggest that the AlN/Gly complex in comparison with the AlN/Gly, AlON/Gly, and the AlCN/Gly complexes could be efficient inhibitors of TNF-α.
Copyright © 2020. Published by Elsevier B.V.