title: Sustained inhibition of the NaV1.7 sodium channel by engineered dimers of the domain II binding peptide GpTx-1.
abstract: Many efforts are underway to develop selective inhibitors of the voltage-gated sodium channel NaV1.7 as new analgesics. Thus far, however, in vitro selectivity has proved difficult for small molecules, and peptides generally lack appropriate pharmacokinetic properties. We previously identified the NaV1.7 inhibitory peptide GpTx-1 from tarantula venom and optimized its potency and selectivity via structure-guided analoging. To further understand GpTx-1 binding to NaV1.7, we have mapped the binding site to transmembrane segments 1-4 of the second pseudosubunit internal repeat (commonly referred to as Site 4) using NaV1.5/NaV1.7 chimeric protein constructs. We also report that select GpTx-1 amino acid residues apparently not contacting NaV1.7 can be derivatized with a hydrophilic polymer without adversely affecting peptide potency. Homodimerization of GpTx-1 with a bifunctional polyethylene glycol (PEG) linker resulted in a compound with increased potency and a significantly reduced off-rate, demonstrating the ability to modulate the function and properties of GpTx-1 by linking to additional molecules.
authors.affiliation: Therapeutic Discovery, Amgen Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, USA. Electronic address: jkmurray@amgen.com.
authors.forename: Justin K
authors.initials: JK
authors.lastname: Murray
authors.affiliation: Therapeutic Discovery, Amgen Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, USA.
authors.forename: Kaustav
authors.initials: K
authors.lastname: Biswas
authors.affiliation: Therapeutic Discovery, Amgen Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, USA.
authors.forename: J Ryan
authors.initials: JR
authors.lastname: Holder
authors.affiliation: Neuroscience, Amgen Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, USA.
authors.forename: Anruo
authors.initials: A
authors.lastname: Zou
authors.affiliation: Neuroscience, Amgen Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Ligutti
authors.affiliation: Neuroscience, Amgen Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, USA.
authors.forename: Dong
authors.initials: D
authors.lastname: Liu
authors.affiliation: Therapeutic Discovery, Amgen Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, USA.
authors.forename: Leszek
authors.initials: L
authors.lastname: Poppe
authors.affiliation: Therapeutic Discovery, Amgen Inc., 360 Binney Street, Cambridge, MA 02142, USA.
authors.forename: Kristin L
authors.initials: KL
authors.lastname: Andrews
authors.affiliation: Biologics, Amgen Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, USA.
authors.forename: Fen-Fen
authors.initials: FF
authors.lastname: Lin
authors.affiliation: Biologics, Amgen Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, USA.
authors.forename: Shi-Yuan
authors.initials: SY
authors.lastname: Meng
authors.affiliation: Neuroscience, Amgen Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, USA.
authors.forename: Bryan D
authors.initials: BD
authors.lastname: Moyer
authors.affiliation: Neuroscience, Amgen Inc., 360 Binney Street, Cambridge, MA 02142, USA.
authors.forename: Stefan I
authors.initials: SI
authors.lastname: McDonough
authors.affiliation: Therapeutic Discovery, Amgen Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, USA.
authors.forename: Les P
authors.initials: LP
authors.lastname: Miranda
mesh_terms: D019281:Dimerization; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008968:Molecular Conformation; D062556:NAV1.7 Voltage-Gated Sodium Channel / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry* / Q000494:pharmacology*; D011485:Protein Binding; D015202:Protein Engineering; D017434:Protein Structure, Tertiary; D013329:Structure-Activity Relationship; D061567:Voltage-Gated Sodium Channel Blockers / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D062556:NAV1.7 Voltage-Gated Sodium Channel; D010455:Peptides; C486866:SCN9A protein, human; D061567:Voltage-Gated Sodium Channel Blockers
keywords: Na(V)1.7; Peptide antagonist; Peptide toxin; Voltage-gated sodium channel