 In addition to the polar interaction, Lys691 participates in a hydrogen bonding network with Glu559, Asp767 and the O5 hydroxyl group of the hydroxyglutartic acid component of the statins.Van der Waals interactions are formed between the hydrophobic side chains of the enzyme, which involve the Leu562, Val683, Leu853, Ala856 and Leu857 and the statins.Type 2 statins form polar interaction between the fluorine atom on the fluorophenyl group and the guanidinium group of Arg590.