title: Docking and molecular dynamics studies on triclosan derivatives binding to FabI.
abstract: FabI, enoyl-ACP reductase (ENR), is the rate-limiting enzyme in the last step for fatty acids biosynthesis in many bacteria. Triclosan (TCL) is a commercial bactericide, and as a FabI inhibitor, it can depress the substrate (trans-2-enoyl-ACP) binding with FabI to hinder the fatty acid synthesis. The structure-activity relationship between TCL derivatives and FabI protein has already been acknowledged, however, their combination at the molecular level has never been investigated. This paper uses the computer-aided approaches, such as molecular docking, molecular dynamics simulation, and binding free energy calculation based on the molecular mechanics/Poisson-Bolzmann surface area (MM/PBSA) method to illustrate the interaction rules of TCL derivatives with FabI and guide the development of new derivatives. The consistent data of the experiment and corresponding activity demonstrates that electron-withdrawing groups on side chain are better than electron-donating groups. 2-Hydroxyl group on A ring, promoting the formation of hydrogen bond, is vital for bactericidal effect; and the substituents at 4-position of A ring, 2'-position and 4'-position of B ring benefit antibacterial activity due to forming a hydrogen bond or stabilizing the conformation of active pocket residues of receptor. While the substituents at 3'-position and 5'-position of B ring destroy the π-π stacking interaction of A ring and NAD+which depresses the antibacterial activity. This study provides a new sight for designing novel TCL derivatives with superior antibacterial activity.
authors.affiliation: Tianjin University of Technology, TianJin, 300384, China.
authors.forename: Xuyun
authors.initials: X
authors.lastname: Yang
authors.affiliation: Tianjin University of Technology, TianJin, 300384, China. lujunrui@tjut.edu.cn.
authors.forename: Junrui
authors.initials: J
authors.lastname: Lu
authors.affiliation: Tianjin University of Technology, TianJin, 300384, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Ying
authors.affiliation: Tianjin University of Technology, TianJin, 300384, China.
authors.forename: Jiangbei
authors.initials: J
authors.lastname: Mu
authors.affiliation: Tianjin University of Technology, TianJin, 300384, China.
authors.forename: Peichun
authors.initials: P
authors.lastname: Li
authors.affiliation: Tianjin University of Technology, TianJin, 300384, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Liu
keywords: Enoyl-ACP reductase; MM-PBSA; Molecular dynamics simulation; Triclosan