Molecular basis of the interaction between gating modifier spider toxins and the voltage sensor of voltage-gated ion channels

Lau, Carus H. Y.; King, Glenn F.; Mobli, Mehdi

doi:10.1038/srep34333

Cited by 47 publications

(89 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…From the sequence analysis our data would support a model where the peptide binds to residues within the cavity formed between the four helices of the VSD II [39]. This model would suggest that there is a large interface between the peptide and the channel, indicating that it should in theory be possible to develop subtype selective peptides.…”

Section: Discussionsupporting

confidence: 57%

The structure, dynamics and selectivity profile of a NaV1.7 potency-optimised huwentoxin-IV variant

et al. 2017

Self Cite

View full text Add to dashboard Cite

Venom-derived peptides have attracted much attention as potential lead molecules for pharmaceutical development. A well-known example is Huwentoxin-IV (HwTx-IV), a peptide toxin isolated from the venom of the Chinese bird-eating spider Haplopelma schmitdi. HwTx-IV was identified as a potent blocker of a human voltage-gated sodium channel (hNaV1.7), which is a genetically validated analgesic target. The peptide was promising as it showed high potency at NaV1.7 (IC50 ~26 nM) and selectivity over the cardiac NaV subtype (NaV1.5). Mutagenesis studies aimed at optimising the potency of the peptide resulted in the development of a triple-mutant of HwTx-IV (E1G, E4G, Y33W, m3-HwTx-IV) with significantly increased potency against hNaV1.7 (IC50 = 0.4 ± 0.1 nM) without increased potency against hNaV1.5. The activity of m3-HwTx-IV against other NaV subtypes was, however, not investigated. Similarly, the structure of the mutant peptide was not characterised, limiting the interpretation of the observed increase in potency. In this study we produced isotope-labelled recombinant m3-HwTx-IV in E. coli, which enabled us to characterise the atomic-resolution structure and dynamics of the peptide by NMR spectroscopy. The results show that the structure of the peptide is not perturbed by the mutations, whilst the relaxation studies reveal that residues in the active site of the peptide undergo conformational exchange. Additionally, the NaV subtype selectivity of the recombinant peptide was characterised, revealing potent inhibition of neuronal NaV subtypes 1.1, 1.2, 1.3, 1.6 and 1.7. In parallel to the in vitro studies, we investigated NaV1.7 target engagement of the peptide in vivo using a rodent pain model, where m3-HwTx-IV dose-dependently suppressed spontaneous pain induced by the NaV1.7 activator OD1. Thus, our results provide further insight into the structure and dynamics of this class of peptides that may prove useful in guiding the development of inhibitors with improved selectivity for analgesic NaV subtypes.

show abstract

Section: Discussionsupporting

confidence: 57%

The structure, dynamics and selectivity profile of a NaV1.7 potency-optimised huwentoxin-IV variant

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…The first of these is in the S1-S2 region of the channel, while the other four are in the S3-S4 region, placing the toxin inside the cavity formed between the four helices of the VSD (note that none of these correspond to the conserved residues shown in Figure 2). This mode of binding is also consistent with recent solution state and mutagenesis studies of other related systems [36,48]. Given that we have in Table 2 Table 2 based on how many of the EELDE motif they have (allowing D to E mutations and L to A/I/V mutations), and we apply a strict filter requiring the final acidic residue (as shown by previous studies to be required) we arrive at the data summarised in Table 3.…”

Section: Hwtx-iv Sensitive Vsdssupporting

confidence: 91%

“…This value would represent the equilibrium dissociation constant between the lipid partitioned ligand and the lipid embedded receptor. Remarkably, however, the value is in good agreement with equilibrium dissociation constants measured between micelle embedded receptors and free ligands [48,55,64].…”

Section: 'Membrane Catalysis' As a Kinetic Model For Contribution Of supporting

confidence: 83%

“…Similarly, GMTs such as hanatoxin [59,60], ProTx-II [61], HHN2B-G7W [53] and SGTx [62] have been shown to bind to lipid bilayers. These and several other studies have also consistently shown that these cationic GMTs have an increased affinity for anionic lipids [48,55,63,64]. The distribution of the basic residues on the GMTs forms a basic patch surrounded by hydrophobic residues creating an amphipathic structure which has been suggested to mediates membrane association by several biophysical studies as well as molecular dynamics simulations [48,[64][65][66].…”

Section: Binding Kinetics Of Spider Toxin Gating Modifierssupporting

confidence: 58%

See 1 more Smart Citation

A complicated complex: Ion channels, voltage sensing, cell membranes and peptide inhibitors

Zhang

Sharma

Undheim

et al. 2018

Neuroscience Letters

Self Cite

View full text Add to dashboard Cite

Voltage-gated ion channels (VGICs) are specialised ion channels that have a voltage dependent mode of action, where ion conduction, or gating, is controlled by a voltage-sensing mechanism. VGICs are critical for electrical signalling and are therefore important pharmacological targets. Among these, voltage-gated sodium channels (Nas) have attracted particular attention as potential analgesic targets. Nas, however, comprise several structurally similar subtypes with unique localisations and distinct functions, ranging from amplification of action potentials in nociception (e.g. Na1.7) to controlling electrical signalling in cardiac function (Na1.5). Understanding the structural basis of Na function is therefore of great significance, both to our knowledge of electrical signalling and in development of subtype and state selective drugs. An important tool in this pursuit has been the use of peptides from animal venoms as selective Na modulators. In this review, we look at peptides, particularly from spider venoms, that inhibit Nas by binding to the voltage sensing domain (VSD) of this channel, known as gating modifier toxins (GMT). In the first part of the review, we look at the structural determinants of voltage sensing in VGICs, the gating cycle and the conformational changes that accompany VSD movement. Next, the modulation of the analgesic target Na1.7 by GMTs is reviewed to develop bioinformatic tools that, based on sequence information alone, can identify toxins that are likely to inhibit this channel. The same approach is also used to define VSD sequences, other than that from Na1.7, which are likely to be sensitive to this class of toxins. The final section of the review focuses on the important role of the cellular membrane in channel modulation and also how the lipid composition affects measurements of peptide-channel interactions both in binding kinetics measurements in solution and in cell-based functional assays.

show abstract

“…Early studies suggested a dominant role for the extracellular S3-S4 loop in GMT binding (7,8), but subsequent studies have revealed a key role for the S1-S2 loop in many GMT interactions (4,9,10). More recent studies suggest that GMTs nestle into an extracellularfacing cavity between the S1 and S4 helices, enabling them to act as a wedge that impedes voltage sensor movement (5,11). It has been suggested that large GMTs such as those found in scorpion venom might be able to simultaneously contact the VSD and the extracellular loop connecting the pore helix P2 and the S6 segment in pore domain (12), but no studies to date have predicted a role for any of the poredomain membrane helices in GMT binding.…”

mentioning

confidence: 99%

Structural basis for the modulation of voltage-gated sodium channels by animal toxins

Shen

Jiang

et al. 2018

Science

Self Cite

218

222

View full text Add to dashboard Cite

Animal toxins that modulate the activity of voltage-gated sodium (Na) channels are broadly divided into two categories-pore blockers and gating modifiers. The pore blockers tetrodotoxin (TTX) and saxitoxin (STX) are responsible for puffer fish and shellfish poisoning in humans, respectively. Here, we present structures of the insect Na channel NaPaS bound to a gating modifier toxin Dc1a at 2.8 angstrom-resolution and in the presence of TTX or STX at 2.6-Å and 3.2-Å resolution, respectively. Dc1a inserts into the cleft between VSD and the pore of NaPaS, making key contacts with both domains. The structures with bound TTX or STX reveal the molecular details for the specific blockade of Na access to the selectivity filter from the extracellular side by these guanidinium toxins. The structures shed light on structure-based development of Na channel drugs.

show abstract

Molecular basis of the interaction between gating modifier spider toxins and the voltage sensor of voltage-gated ion channels

Cited by 47 publications

References 53 publications

The structure, dynamics and selectivity profile of a NaV1.7 potency-optimised huwentoxin-IV variant

The structure, dynamics and selectivity profile of a NaV1.7 potency-optimised huwentoxin-IV variant

A complicated complex: Ion channels, voltage sensing, cell membranes and peptide inhibitors

Structural basis for the modulation of voltage-gated sodium channels by animal toxins

Contact Info

Product

Resources

About