Membrane-binding properties of gating modifier and pore-blocking toxins: Membrane interaction is not a prerequisite for modification of channel gating

Many venom peptides are potent and selective inhibitors of voltage-gated ion channels, including channels that are validated therapeutic targets for treatment of a wide range of human diseases. However, the development of novel venom-peptide-based therapeutics requires an understanding of their mech...

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Main Authors: Deplazes, Evelyne, Henriques, S., Smith, J., King, G., Craik, D., Mark, A., Schroeder, C.
Format: Journal Article
Published: Elsevier 2016
Online Access:http://hdl.handle.net/20.500.11937/35515
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author Deplazes, Evelyne
Henriques, S.
Smith, J.
King, G.
Craik, D.
Mark, A.
Schroeder, C.
author_facet Deplazes, Evelyne
Henriques, S.
Smith, J.
King, G.
Craik, D.
Mark, A.
Schroeder, C.
author_sort Deplazes, Evelyne
building Curtin Institutional Repository
collection Online Access
description Many venom peptides are potent and selective inhibitors of voltage-gated ion channels, including channels that are validated therapeutic targets for treatment of a wide range of human diseases. However, the development of novel venom-peptide-based therapeutics requires an understanding of their mechanism of action. In the case of voltage-gated ion channels, venom peptides act either as pore blockers that bind to the extracellular side of the channel pore or gating modifiers that bind to one or more of the membrane-embedded voltage sensor domains. In the case of gating modifiers, it has been debated whether the peptide must partition into the membrane to reach its binding site. In this study, we used surface plasmon resonance, fluorescence spectroscopy and molecular dynamics to directly compare the lipid-binding properties of two gating modifiers (µ-TRTX-Hd1a and ProTx-I) and two pore blockers (ShK and KIIIA). Only ProTx-I was found to bind to model membranes. Our results provide further evidence that the ability to insert into the lipid bilayer is not a requirement to be a gating modifier. In addition, we characterised the surface of ProTx-I that mediates its interaction with neutral and anionic phospholipid membranes and show that it preferentially interacts with anionic lipids.
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spelling curtin-20.500.11937-355152017-09-13T15:46:01Z Membrane-binding properties of gating modifier and pore-blocking toxins: Membrane interaction is not a prerequisite for modification of channel gating Deplazes, Evelyne Henriques, S. Smith, J. King, G. Craik, D. Mark, A. Schroeder, C. Many venom peptides are potent and selective inhibitors of voltage-gated ion channels, including channels that are validated therapeutic targets for treatment of a wide range of human diseases. However, the development of novel venom-peptide-based therapeutics requires an understanding of their mechanism of action. In the case of voltage-gated ion channels, venom peptides act either as pore blockers that bind to the extracellular side of the channel pore or gating modifiers that bind to one or more of the membrane-embedded voltage sensor domains. In the case of gating modifiers, it has been debated whether the peptide must partition into the membrane to reach its binding site. In this study, we used surface plasmon resonance, fluorescence spectroscopy and molecular dynamics to directly compare the lipid-binding properties of two gating modifiers (µ-TRTX-Hd1a and ProTx-I) and two pore blockers (ShK and KIIIA). Only ProTx-I was found to bind to model membranes. Our results provide further evidence that the ability to insert into the lipid bilayer is not a requirement to be a gating modifier. In addition, we characterised the surface of ProTx-I that mediates its interaction with neutral and anionic phospholipid membranes and show that it preferentially interacts with anionic lipids. 2016 Journal Article http://hdl.handle.net/20.500.11937/35515 10.1016/j.bbamem.2016.02.002 Elsevier fulltext
spellingShingle Deplazes, Evelyne
Henriques, S.
Smith, J.
King, G.
Craik, D.
Mark, A.
Schroeder, C.
Membrane-binding properties of gating modifier and pore-blocking toxins: Membrane interaction is not a prerequisite for modification of channel gating
title Membrane-binding properties of gating modifier and pore-blocking toxins: Membrane interaction is not a prerequisite for modification of channel gating
title_full Membrane-binding properties of gating modifier and pore-blocking toxins: Membrane interaction is not a prerequisite for modification of channel gating
title_fullStr Membrane-binding properties of gating modifier and pore-blocking toxins: Membrane interaction is not a prerequisite for modification of channel gating
title_full_unstemmed Membrane-binding properties of gating modifier and pore-blocking toxins: Membrane interaction is not a prerequisite for modification of channel gating
title_short Membrane-binding properties of gating modifier and pore-blocking toxins: Membrane interaction is not a prerequisite for modification of channel gating
title_sort membrane-binding properties of gating modifier and pore-blocking toxins: membrane interaction is not a prerequisite for modification of channel gating
url http://hdl.handle.net/20.500.11937/35515