Revealing a notable interaction in the binding of type II statins to HMG‐CoA reductase: Stacked cation–π interaction.

This study has centered on potentially important enzyme‐ligand interaction currently not incorporated: stacked cation–π interaction between the guanidinium group of arginine 590 residues in the HMG‐CoA reductase active site and the 4‐fluorophenyl group of type II statins. The geometry of interaction between these planar groups has been considered based on the X‐ray crystallographic structures already available in the protein data bank (PDB) archive. Electronic interaction energies between this residue and statins have been acquired by M06 and MP2 methods. In addition, stacking interaction and hydrogen bonding as two important investigated interactions are verified through prominent analyses: (1) quantum theory of atoms in molecules (QTAIM) analysis; (2) plotting and quantitative molecular surface analyses such as electrostatic potential (ESP) analysis, Hirshfeld surface (HS) and Becke surface (BS) analyses; (3) visual study methods such as noncovalent interaction (NCI), independent gradient model (IGM) analyses; and (4) localized orbital locator integrated pi over plane (LOLIPOP) index. The results indicate the absolute binding energy for type II statins is overall more than for type I statins. [ABSTRACT FROM AUTHOR]