title: Warfarin traps human vitamin K epoxide reductase in an intermediate state during electron transfer.
abstract: Although warfarin is the most widely used anticoagulant worldwide, the mechanism by which warfarin inhibits its target, human vitamin K epoxide reductase (hVKOR), remains unclear. Here we show that warfarin blocks a dynamic electron-transfer process in hVKOR. A major fraction of cellular hVKOR is in an intermediate redox state containing a Cys51-Cys132 disulfide, a characteristic accommodated by a four-transmembrane-helix structure of hVKOR. Warfarin selectively inhibits this major cellular form of hVKOR, whereas disruption of the Cys51-Cys132 disulfide impairs warfarin binding and causes warfarin resistance. Relying on binding interactions identified by cysteine alkylation footprinting and mass spectrometry coupled with mutagenesis analysis, we conducted structure simulations, which revealed a closed warfarin-binding pocket stabilized by the Cys51-Cys132 linkage. Understanding the selective warfarin inhibition of a specific redox state of hVKOR should enable the rational design of drugs that exploit the redox chemistry and associated conformational changes in hVKOR.
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Guomin
authors.initials: G
authors.lastname: Shen
authors.affiliation: Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri, USA.
authors.forename: Weidong
authors.initials: W
authors.lastname: Cui
authors.affiliation: Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri, USA.
authors.forename: Hao
authors.identifier: 0000-0002-6129-6410
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Fengbo
authors.initials: F
authors.lastname: Zhou
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, USA.|School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, USA.|Department of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Yihu
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Shuang
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Gregory R
authors.initials: GR
authors.lastname: Bowman
authors.affiliation: Division of Hematology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: J Evan
authors.initials: JE
authors.lastname: Sadler
authors.affiliation: Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Gross
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Weikai
authors.initials: W
authors.lastname: Li
mesh_terms: D055162:Biocatalysis; D020134:Catalytic Domain; D057809:HEK293 Cells; D006801:Humans; D062105:Molecular Docking Simulation; D010084:Oxidation-Reduction; D011485:Protein Binding; D010837:Vitamin K 1 / Q000031:analogs & derivatives / Q000737:chemistry; D024482:Vitamin K 2 / Q000737:chemistry; D064417:Vitamin K Epoxide Reductases / Q000037:antagonists & inhibitors / Q000737:chemistry*; D014859:Warfarin / Q000737:chemistry*
chemical_list: D024482:Vitamin K 2; C016186:vitamin K1 oxide; D014859:Warfarin; D010837:Vitamin K 1; D064417:Vitamin K Epoxide Reductases