title: Structural basis of Nav1.7 inhibition by an isoform-selective small-molecule antagonist.
abstract: Voltage-gated sodium (Nav) channels propagate action potentials in excitable cells. Accordingly, Nav channels are therapeutic targets for many cardiovascular and neurological disorders. Selective inhibitors have been challenging to design because the nine mammalian Nav channel isoforms share high sequence identity and remain recalcitrant to high-resolution structural studies. Targeting the human Nav1.7 channel involved in pain perception, we present a protein-engineering strategy that has allowed us to determine crystal structures of a novel receptor site in complex with isoform-selective antagonists. GX-936 and related inhibitors bind to the activated state of voltage-sensor domain IV (VSD4), where their anionic aryl sulfonamide warhead engages the fourth arginine gating charge on the S4 helix. By opposing VSD4 deactivation, these compounds inhibit Nav1.7 through a voltage-sensor trapping mechanism, likely by stabilizing inactivated states of the channel. Residues from the S2 and S3 helices are key determinants of isoform selectivity, and bound phospholipids implicate the membrane as a modulator of channel function and pharmacology. Our results help to elucidate the molecular basis of voltage sensing and establish structural blueprints to design selective Nav channel antagonists.
authors.affiliation: Department of Structural Biology, Genentech Inc., South San Francisco, CA 94080, USA.
authors.forename: Shivani
authors.initials: S
authors.lastname: Ahuja
authors.affiliation: Department of Structural Biology, Genentech Inc., South San Francisco, CA 94080, USA.
authors.forename: Susmith
authors.initials: S
authors.lastname: Mukund
authors.affiliation: Department of Neuroscience, Genentech Inc., South San Francisco, CA 94080, USA.
authors.forename: Lunbin
authors.initials: L
authors.lastname: Deng
authors.affiliation: Department of Biology, Xenon Pharmaceuticals Inc., Burnaby, British Columbia, V5G 4W8, Canada.
authors.forename: Kuldip
authors.initials: K
authors.lastname: Khakh
authors.affiliation: Department of Biology, Xenon Pharmaceuticals Inc., Burnaby, British Columbia, V5G 4W8, Canada.
authors.forename: Elaine
authors.initials: E
authors.lastname: Chang
authors.affiliation: Department of Structural Biology, Genentech Inc., South San Francisco, CA 94080, USA.
authors.forename: Hoangdung
authors.initials: H
authors.lastname: Ho
authors.affiliation: Department of Structural Biology, Genentech Inc., South San Francisco, CA 94080, USA.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Shriver
authors.affiliation: Department of Biology, Xenon Pharmaceuticals Inc., Burnaby, British Columbia, V5G 4W8, Canada.
authors.forename: Clint
authors.initials: C
authors.lastname: Young
authors.affiliation: Department of Biology, Xenon Pharmaceuticals Inc., Burnaby, British Columbia, V5G 4W8, Canada.
authors.forename: Sophia
authors.initials: S
authors.lastname: Lin
authors.affiliation: Department of Biology, Xenon Pharmaceuticals Inc., Burnaby, British Columbia, V5G 4W8, Canada.
authors.forename: J P
authors.initials: JP
authors.lastname: Johnson
authors.affiliation: Department of Structural Biology, Genentech Inc., South San Francisco, CA 94080, USA.
authors.forename: Ping
authors.initials: P
authors.lastname: Wu
authors.affiliation: Department of Discovery Chemistry, Genentech Inc., South San Francisco, CA 94080, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Structural Biology, Genentech Inc., South San Francisco, CA 94080, USA.
authors.forename: Mary
authors.initials: M
authors.lastname: Coons
authors.affiliation: Department of Structural Biology, Genentech Inc., South San Francisco, CA 94080, USA.
authors.forename: Christine
authors.initials: C
authors.lastname: Tam
authors.affiliation: Department of Structural Biology, Genentech Inc., South San Francisco, CA 94080, USA.
authors.forename: Bobby
authors.initials: B
authors.lastname: Brillantes
authors.affiliation: Department of Structural Biology, Genentech Inc., South San Francisco, CA 94080, USA.
authors.forename: Honorio
authors.initials: H
authors.lastname: Sampang
authors.affiliation: Department of Structural Biology, Genentech Inc., South San Francisco, CA 94080, USA.
authors.forename: Kyle
authors.initials: K
authors.lastname: Mortara
authors.affiliation: Department of Structural Biology, Genentech Inc., South San Francisco, CA 94080, USA.
authors.forename: Krista K
authors.initials: KK
authors.lastname: Bowman
authors.affiliation: Department of Biochemical and Cellular Pharmacology, Genentech Inc., South San Francisco, CA 94080, USA.
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Clark
authors.affiliation: Department of Structural Biology, Genentech Inc., South San Francisco, CA 94080, USA.
authors.forename: Alberto
authors.initials: A
authors.lastname: Estevez
authors.affiliation: Department of Biology, Xenon Pharmaceuticals Inc., Burnaby, British Columbia, V5G 4W8, Canada.
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Xie
authors.affiliation: Department of Biology, Xenon Pharmaceuticals Inc., Burnaby, British Columbia, V5G 4W8, Canada.
authors.forename: Henry
authors.initials: H
authors.lastname: Verschoof
authors.affiliation: Department of Chemistry, Xenon Pharmaceuticals Inc., Burnaby, British Columbia, V5G 4W8, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Grimwood
authors.affiliation: Department of Chemistry, Xenon Pharmaceuticals Inc., Burnaby, British Columbia, V5G 4W8, Canada.
authors.forename: Christoph
authors.initials: C
authors.lastname: Dehnhardt
authors.affiliation: Department of Chemistry, Xenon Pharmaceuticals Inc., Burnaby, British Columbia, V5G 4W8, Canada.
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Andrez
authors.affiliation: Department of Chemistry, Xenon Pharmaceuticals Inc., Burnaby, British Columbia, V5G 4W8, Canada.
authors.forename: Thilo
authors.initials: T
authors.lastname: Focken
authors.affiliation: Department of Discovery Chemistry, Genentech Inc., South San Francisco, CA 94080, USA.
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Sutherlin
authors.affiliation: Department of Discovery Chemistry, Genentech Inc., South San Francisco, CA 94080, USA.
authors.forename: Brian S
authors.initials: BS
authors.lastname: Safina
authors.affiliation: Department of Structural Biology, Genentech Inc., South San Francisco, CA 94080, USA.
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Starovasnik
authors.affiliation: Department of Discovery Chemistry, Genentech Inc., South San Francisco, CA 94080, USA.
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Ortwine
authors.affiliation: Department of Structural Biology, Genentech Inc., South San Francisco, CA 94080, USA.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Franke
authors.affiliation: Department of Biology, Xenon Pharmaceuticals Inc., Burnaby, British Columbia, V5G 4W8, Canada.
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Cohen
authors.affiliation: Department of Neuroscience, Genentech Inc., South San Francisco, CA 94080, USA. hackos.david@gene.com koth.christopher@gene.com payandeh.jian@gene.com.
authors.forename: David H
authors.initials: DH
authors.lastname: Hackos
authors.affiliation: Department of Structural Biology, Genentech Inc., South San Francisco, CA 94080, USA. hackos.david@gene.com koth.christopher@gene.com payandeh.jian@gene.com.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Koth
authors.affiliation: Department of Structural Biology, Genentech Inc., South San Francisco, CA 94080, USA. hackos.david@gene.com koth.christopher@gene.com payandeh.jian@gene.com.
authors.forename: Jian
authors.initials: J
authors.lastname: Payandeh
mesh_terms: D000595:Amino Acid Sequence; D002462:Cell Membrane / Q000737:chemistry; D003460:Crystallization / Q000379:methods; D018360:Crystallography, X-Ray; D004252:DNA Mutational Analysis; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D062556:NAV1.7 Voltage-Gated Sodium Channel / Q000737:chemistry* / Q000235:genetics; D058748:Pain Perception / Q000187:drug effects; D015202:Protein Engineering; D020033:Protein Isoforms / Q000037:antagonists & inhibitors / Q000737:chemistry; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D026941:Sodium Channel Blockers / Q000737:chemistry* / Q000494:pharmacology*; D013449:Sulfonamides / Q000737:chemistry* / Q000494:pharmacology*; D013830:Thiadiazoles / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: C000604117:GX-936; D062556:NAV1.7 Voltage-Gated Sodium Channel; D020033:Protein Isoforms; C486866:SCN9A protein, human; D026941:Sodium Channel Blockers; D013449:Sulfonamides; D013830:Thiadiazoles