1
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Jiang Y, Castro J, Blomster LV, Agwa AJ, Maddern J, Schober G, Herzig V, Chow CY, Cardoso FC, Demétrio De Souza França P, Gonzales J, Schroeder CI, Esche S, Reiner T, Brierley SM, King GF. Pharmacological Inhibition of the Voltage-Gated Sodium Channel Na V1.7 Alleviates Chronic Visceral Pain in a Rodent Model of Irritable Bowel Syndrome. ACS Pharmacol Transl Sci 2021; 4:1362-1378. [PMID: 34423271 DOI: 10.1021/acsptsci.1c00072] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Indexed: 12/12/2022]
Abstract
The human nociceptor-specific voltage-gated sodium channel 1.7 (hNaV1.7) is critical for sensing various types of somatic pain, but it appears not to play a primary role in acute visceral pain. However, its role in chronic visceral pain remains to be determined. We used assay-guided fractionation to isolate a novel hNaV1.7 inhibitor, Tsp1a, from tarantula venom. Tsp1a is 28-residue peptide that potently inhibits hNaV1.7 (IC50 = 10 nM), with greater than 100-fold selectivity over hNaV1.3-hNaV1.6, 45-fold selectivity over hNaV1.1, and 24-fold selectivity over hNaV1.2. Tsp1a is a gating modifier that inhibits NaV1.7 by inducing a hyperpolarizing shift in the voltage-dependence of channel inactivation and slowing recovery from fast inactivation. NMR studies revealed that Tsp1a adopts a classical knottin fold, and like many knottin peptides, it is exceptionally stable in human serum. Remarkably, intracolonic administration of Tsp1a completely reversed chronic visceral hypersensitivity in a mouse model of irritable bowel syndrome. The ability of Tsp1a to reduce visceral hypersensitivity in a model of irritable bowel syndrome suggests that pharmacological inhibition of hNaV1.7 at peripheral sensory nerve endings might be a viable approach for eliciting analgesia in patients suffering from chronic visceral pain.
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Affiliation(s)
- Yan Jiang
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Joel Castro
- Visceral Pain Research Group, College of Medicine and Public Health, Flinders Health and Medical Research Institute, Flinders University, Bedford Park, South Australia 5042, Australia.,Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia 5000, Australia
| | - Linda V Blomster
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Akello J Agwa
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Jessica Maddern
- Visceral Pain Research Group, College of Medicine and Public Health, Flinders Health and Medical Research Institute, Flinders University, Bedford Park, South Australia 5042, Australia.,Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia 5000, Australia
| | - Gudrun Schober
- Visceral Pain Research Group, College of Medicine and Public Health, Flinders Health and Medical Research Institute, Flinders University, Bedford Park, South Australia 5042, Australia.,Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia 5000, Australia
| | - Volker Herzig
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Chun Yuen Chow
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Fernanda C Cardoso
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Paula Demétrio De Souza França
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States.,Department of Otorhinolaryngology & Head and Neck Surgery, Federal University of São Paulo, São Paulo 04021-001, Brazil
| | - Junior Gonzales
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
| | - Christina I Schroeder
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | | | - Thomas Reiner
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States.,Department of Radiology, Weill Cornell Medical College, New York, New York 10021, United States
| | - Stuart M Brierley
- Visceral Pain Research Group, College of Medicine and Public Health, Flinders Health and Medical Research Institute, Flinders University, Bedford Park, South Australia 5042, Australia.,Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia 5000, Australia.,Discipline of Medicine, University of Adelaide, Adelaide, South Australia 5000, Australia
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia.,Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, St. Lucia, Queensland 4072, Australia
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2
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Agwa AJ, Tran P, Mueller A, Tran HNT, Deuis JR, Israel MR, McMahon KL, Craik DJ, Vetter I, Schroeder CI. Manipulation of a spider peptide toxin alters its affinity for lipid bilayers and potency and selectivity for voltage-gated sodium channel subtype 1.7. J Biol Chem 2020; 295:5067-5080. [PMID: 32139508 PMCID: PMC7152767 DOI: 10.1074/jbc.ra119.012281] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 03/03/2020] [Indexed: 02/05/2023] Open
Abstract
Huwentoxin-IV (HwTx-IV) is a gating modifier peptide toxin from spiders that has weak affinity for the lipid bilayer. As some gating modifier toxins have affinity for model lipid bilayers, a tripartite relationship among gating modifier toxins, voltage-gated ion channels, and the lipid membrane surrounding the channels has been proposed. We previously designed an HwTx-IV analogue (gHwTx-IV) with reduced negative charge and increased hydrophobic surface profile, which displays increased lipid bilayer affinity and in vitro activity at the voltage-gated sodium channel subtype 1.7 (NaV1.7), a channel targeted in pain management. Here, we show that replacements of the positively-charged residues that contribute to the activity of the peptide can improve gHwTx-IV's potency and selectivity for NaV1.7. Using HwTx-IV, gHwTx-IV, [R26A]gHwTx-IV, [K27A]gHwTx-IV, and [R29A]gHwTx-IV variants, we examined their potency and selectivity at human NaV1.7 and their affinity for the lipid bilayer. [R26A]gHwTx-IV consistently displayed the most improved potency and selectivity for NaV1.7, examined alongside off-target NaVs, compared with HwTx-IV and gHwTx-IV. The lipid affinity of each of the three novel analogues was weaker than that of gHwTx-IV, but stronger than that of HwTx-IV, suggesting a possible relationship between in vitro potency at NaV1.7 and affinity for lipid bilayers. In a murine NaV1.7 engagement model, [R26A]gHwTx-IV exhibited an efficacy comparable with that of native HwTx-IV. In summary, this study reports the development of an HwTx-IV analogue with improved in vitro selectivity for the pain target NaV1.7 and with an in vivo efficacy similar to that of native HwTx-IV.
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Affiliation(s)
- Akello J Agwa
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Poanna Tran
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Alexander Mueller
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Hue N T Tran
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Jennifer R Deuis
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Mathilde R Israel
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Kirsten L McMahon
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - David J Craik
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Irina Vetter
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
- School of Pharmacy, The University of Queensland, Woolloongabba, Queensland 4103, Australia
| | - Christina I Schroeder
- Institute for Molecular Bioscience, Centre for Pain Research, The University of Queensland, Brisbane, Queensland 4072, Australia
- National Cancer Institute, National Institutes of Health, Frederick, Maryland 21702, USA
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3
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Jin J, Agwa AJ, Szanto TG, Csóti A, Panyi G, Schroeder CI, Walker AA, King GF. Weaponisation 'on the fly': Convergent recruitment of knottin and defensin peptide scaffolds into the venom of predatory assassin flies. Insect Biochem Mol Biol 2020; 118:103310. [PMID: 31870846 DOI: 10.1016/j.ibmb.2019.103310] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 12/12/2019] [Accepted: 12/16/2019] [Indexed: 06/10/2023]
Abstract
Many arthropod venom peptides have potential as bioinsecticides, drug leads, and pharmacological tools due to their specific neuromodulatory functions. Assassin flies (Asilidae) are a family of predaceous dipterans that produce a unique and complex peptide-rich venom for killing insect prey and deterring predators. However, very little is known about the structure and function of their venom peptides. We therefore used an E. coli periplasmic expression system to express four disulfide-rich peptides that we previously reported to exist in venom of the giant assassin fly Dolopus genitalis. After purification, each recombinant peptide eluted from a C18 column at a position closely matching its natural counterpart, strongly suggesting adoption of the native tertiary fold. Injection of purified recombinant peptides into blowflies (Lucilia cuprina) and crickets (Acheta domestica) revealed that two of the four recombinant peptides, named rDg3b and rDg12, inhibited escape behaviour in a manner that was rapid in onset (<1 min) and reversible. Homonuclear NMR solution structures revealed that rDg3b and rDg12 adopt cystine-stabilised α/ß defensin and inhibitor cystine knot folds, respectively. Although the closest known homologues of rDg3b at the level of primary structure are dipteran antimicrobial peptides such as sapecin and lucifensin, a DALI search showed that the tertiary structure of rDg3b most closely resembles the KV11.1-specific α-potassium channel toxin CnErg1 from venom of the scorpion Centruroides noxius. This is mainly due to the deletion of a large, unstructured loop between the first and second cysteine residues present in Dg3b homologues from non-asiloid, but not existing in asiloid, species. Patch-clamp electrophysiology experiments revealed that rDg3b shifts the voltage-dependence of KV11.1 channel activation to more depolarised potentials, but has no effect on KV1.3, KV2.1, KV10.1, KCa1.1, or the Drosophila Shaker channel. Although rDg12 shares the inhibitor cystine knot structure of many gating modifier toxins, rDg12 did not affect any of these KV channel subtypes. Our results demonstrate that multiple disulfide-rich peptide scaffolds have been convergently recruited into asilid and other animal venoms, and they provide insight into the molecular evolution accompanying their weaponisation.
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Affiliation(s)
- Jiayi Jin
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Akello J Agwa
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Tibor G Szanto
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, H-4032, Hungary
| | - Agota Csóti
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, H-4032, Hungary
| | - Gyorgy Panyi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, H-4032, Hungary
| | - Christina I Schroeder
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Andrew A Walker
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia.
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia.
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Mueller A, Dekan Z, Kaas Q, Agwa AJ, Starobova H, Alewood PF, Schroeder CI, Mobli M, Deuis JR, Vetter I. Mapping the Molecular Surface of the Analgesic Na V1.7-Selective Peptide Pn3a Reveals Residues Essential for Membrane and Channel Interactions. ACS Pharmacol Transl Sci 2020; 3:535-546. [PMID: 32566918 DOI: 10.1021/acsptsci.0c00002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Indexed: 12/18/2022]
Abstract
Compelling human genetic studies have identified the voltage-gated sodium channel NaV1.7 as a promising therapeutic target for the treatment of pain. The analgesic spider-venom-derived peptide μ-theraphotoxin-Pn3a is an exceptionally potent and selective inhibitor of NaV1.7; however, little is known about the structure-activity relationships or channel interactions that define this activity. We rationally designed 17 Pn3a analogues and determined their activity at hNaV1.7 using patch-clamp electrophysiology. The positively charged amino acids K22 and K24 were identified as crucial for Pn3a activity, with molecular modeling identifying interactions of these residues with the S3-S4 loop of domain II of hNaV1.7. Removal of hydrophobic residues Y4, Y27, and W30 led to a loss of potency (>250-fold), while replacement of negatively charged D1 and D8 residues with a positively charged lysine led to increased potencies (>13-fold), likely through alterations in membrane lipid interactions. Mutating D8 to an asparagine led to the greatest improvement in Pn3a potency at NaV1.7 (20-fold), while maintaining >100-fold selectivity over the major off-targets NaV1.4, NaV1.5, and NaV1.6. The Pn3a[D8N] mutant retained analgesic activity in vivo, significantly attenuating mechanical allodynia in a clinically relevant mouse model of postsurgical pain at doses 3-fold lower than those with wild-type Pn3a, without causing motor-adverse effects. Results from this study will facilitate future rational design of potent and selective peptidic NaV1.7 inhibitors for the development of more efficacious and safer analgesics as well as to further investigate the involvement of NaV1.7 in pain.
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Affiliation(s)
- Alexander Mueller
- Institute for Molecular Bioscience, The University of Queensland, 306 Carmody Road, St. Lucia, Queensland 4072, Australia
| | - Zoltan Dekan
- Institute for Molecular Bioscience, The University of Queensland, 306 Carmody Road, St. Lucia, Queensland 4072, Australia
| | - Quentin Kaas
- Institute for Molecular Bioscience, The University of Queensland, 306 Carmody Road, St. Lucia, Queensland 4072, Australia
| | - Akello J Agwa
- Institute for Molecular Bioscience, The University of Queensland, 306 Carmody Road, St. Lucia, Queensland 4072, Australia
| | - Hana Starobova
- Institute for Molecular Bioscience, The University of Queensland, 306 Carmody Road, St. Lucia, Queensland 4072, Australia
| | - Paul F Alewood
- Institute for Molecular Bioscience, The University of Queensland, 306 Carmody Road, St. Lucia, Queensland 4072, Australia
| | - Christina I Schroeder
- Institute for Molecular Bioscience, The University of Queensland, 306 Carmody Road, St. Lucia, Queensland 4072, Australia
| | - Mehdi Mobli
- Centre for Advanced Imaging, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Jennifer R Deuis
- Institute for Molecular Bioscience, The University of Queensland, 306 Carmody Road, St. Lucia, Queensland 4072, Australia
| | - Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, 306 Carmody Road, St. Lucia, Queensland 4072, Australia.,School of Pharmacy, The University of Queensland, Woolloongabba, Queensland 4102, Australia
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5
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Tran HNT, Tran P, Deuis JR, Agwa AJ, Zhang AH, Vetter I, Schroeder CI. Enzymatic Ligation of a Pore Blocker Toxin and a Gating Modifier Toxin: Creating Double-Knotted Peptides with Improved Sodium Channel NaV1.7 Inhibition. Bioconjug Chem 2019; 31:64-73. [DOI: 10.1021/acs.bioconjchem.9b00744] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Hue N. T. Tran
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Poanna Tran
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Jennifer R. Deuis
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Akello J. Agwa
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Alan H. Zhang
- Center for Advanced Imaging, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
- School of Pharmacy, The University of Queensland, Woolloongabba, Queensland 4102, Australia
| | - Christina I. Schroeder
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
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6
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Gonzales J, Demetrio de Souza Franca P, Jiang Y, Pirovano G, Kossatz S, Guru N, Yarilin D, Agwa AJ, Schroeder CI, Patel SG, Ganly I, King GF, Reiner T. Fluorescence Imaging of Peripheral Nerves by a Na v1.7-Targeted Inhibitor Cystine Knot Peptide. Bioconjug Chem 2019; 30:2879-2888. [PMID: 31647222 DOI: 10.1021/acs.bioconjchem.9b00612] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Twenty million Americans suffer from peripheral nerve injury caused by trauma and medical disorders, resulting in a broad spectrum of potentially debilitating side effects. In one out of four cases, patients identify surgery as the root cause of their nerve injury. Particularly during tumor resections or after traumatic injuries, tissue distortion and poor visibility can challenge a surgeon's ability to precisely locate and preserve peripheral nerves. Intuitively, surgical outcomes would improve tremendously if nerves could be highlighted using an exogeneous contrast agent. In clinical practice, however, the current standard of care-visual examination and palpation-remains unchanged. To address this unmet clinical need, we explored the expression of voltage-gated sodium channel Nav1.7 as an intraoperative marker for the peripheral nervous system. We show that expression of Nav1.7 is high in peripheral nerves harvested from both human and mouse tissue. We further show that modification of a Nav1.7-selective peptide, Hsp1a, can serve as a targeted vector for delivering a fluorescent sensor to the peripheral nervous system. Ex vivo, we observe a high signal-to-noise ratio for fluorescently labeled Hsp1a in both histologically prepared and fresh tissue. Using a surgical fluorescent microscope, we show in a simulated clinical scenario that the identification of mouse sciatic nerves is possible, suggesting that fluorescently labeled Hsp1a tracers could be used to discriminate nerves from their surrounding tissues in a routine clinical setting.
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Affiliation(s)
| | | | - Yan Jiang
- Institute for Molecular Bioscience , The University of Queensland , St Lucia , Queensland 4072 , Australia
| | | | | | | | | | - Akello J Agwa
- Institute for Molecular Bioscience , The University of Queensland , St Lucia , Queensland 4072 , Australia
| | - Christina I Schroeder
- Institute for Molecular Bioscience , The University of Queensland , St Lucia , Queensland 4072 , Australia
| | | | | | - Glenn F King
- Institute for Molecular Bioscience , The University of Queensland , St Lucia , Queensland 4072 , Australia
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Abstract
Sortase A (SrtA) is an enzyme obtained from Staphylococcus aureus that catalyzes site-specific transpeptidation of surface proteins to the bacterial cell membrane. SrtA recognizes an LPXTG amino acid motif and cleaves between the Thr and Gly to form a thioester-linked acyl-enzyme intermediate. The intermediate is resolved in the presence of a nucleophilic N-terminal polyglycine resulting in ligation of the acyl donor to the polyglycine acceptor. Here we describe the application of SrtA as a tool for the cyclization of disulfide-rich peptides. Reactions are typically tailored to each disulfide-rich peptide with optimal conditions producing yields of 40-50% cyclized peptide.
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Affiliation(s)
- Akello J Agwa
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - David J Craik
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia.
| | - Christina I Schroeder
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia.
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8
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Agwa AJ, Blomster LV, Craik DJ, King GF, Schroeder CI. Efficient Enzymatic Ligation of Inhibitor Cystine Knot Spider Venom Peptides: Using Sortase A To Form Double-Knottins That Probe Voltage-Gated Sodium Channel NaV1.7. Bioconjug Chem 2018; 29:3309-3319. [DOI: 10.1021/acs.bioconjchem.8b00505] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Akello J. Agwa
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Linda V. Blomster
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - David J. Craik
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Glenn F. King
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Christina I. Schroeder
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
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9
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Agwa AJ, Peigneur S, Chow CY, Lawrence N, Craik DJ, Tytgat J, King GF, Henriques ST, Schroeder CI. Gating modifier toxins isolated from spider venom: Modulation of voltage-gated sodium channels and the role of lipid membranes. J Biol Chem 2018; 293:9041-9052. [PMID: 29703751 DOI: 10.1074/jbc.ra118.002553] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Revised: 04/25/2018] [Indexed: 11/06/2022] Open
Abstract
Gating modifier toxins (GMTs) are venom-derived peptides isolated from spiders and other venomous creatures and modulate activity of disease-relevant voltage-gated ion channels and are therefore being pursued as therapeutic leads. The amphipathic surface profile of GMTs has prompted the proposal that some GMTs simultaneously bind to the cell membrane and voltage-gated ion channels in a trimolecular complex. Here, we examined whether there is a relationship among spider GMT amphipathicity, membrane binding, and potency or selectivity for voltage-gated sodium (NaV) channels. We used NMR spectroscopy and in silico calculations to examine the structures and physicochemical properties of a panel of nine GMTs and deployed surface plasmon resonance to measure GMT affinity for lipids putatively found in proximity to NaV channels. Electrophysiology was used to quantify GMT activity on NaV1.7, an ion channel linked to chronic pain. Selectivity of the peptides was further examined against a panel of NaV channel subtypes. We show that GMTs adsorb to the outer leaflet of anionic lipid bilayers through electrostatic interactions. We did not observe a direct correlation between GMT amphipathicity and affinity for lipid bilayers. Furthermore, GMT-lipid bilayer interactions did not correlate with potency or selectivity for NaVs. We therefore propose that increased membrane binding is unlikely to improve subtype selectivity and that the conserved amphipathic GMT surface profile is an adaptation that facilitates simultaneous modulation of multiple NaVs.
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Affiliation(s)
- Akello J Agwa
- From the Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia and
| | - Steve Peigneur
- Laboratory of Toxicology and Pharmacology, University of Leuven (KU Leuven), 3000 Leuven, Belgium
| | - Chun Yuen Chow
- From the Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia and
| | - Nicole Lawrence
- From the Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia and
| | - David J Craik
- From the Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia and
| | - Jan Tytgat
- Laboratory of Toxicology and Pharmacology, University of Leuven (KU Leuven), 3000 Leuven, Belgium
| | - Glenn F King
- From the Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia and
| | - Sónia Troeira Henriques
- From the Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia and
| | - Christina I Schroeder
- From the Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia and
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10
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Agwa AJ, Lawrence N, Deplazes E, Cheneval O, Chen RM, Craik DJ, Schroeder CI, Henriques ST. Corrigendum to "Spider peptide toxin HwTx-IV engineered to bind to lipid membranes has an increased inhibitory potency at human voltage-gated sodium channel hNa V1.7" [Biochim. Biophys. Acta 1859(5) (2017) 835-844]. Biochim Biophys Acta Biomembr 2017; 1859:2277. [PMID: 28842331 DOI: 10.1016/j.bbamem.2017.08.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Affiliation(s)
- Akello J Agwa
- Institute for Molecular Bioscience, The University of Queensland, QLD 4072, Australia
| | - Nicole Lawrence
- Institute for Molecular Bioscience, The University of Queensland, QLD 4072, Australia
| | - Evelyne Deplazes
- Institute for Molecular Bioscience, The University of Queensland, QLD 4072, Australia; School of Chemistry and Molecular Biosciences, The University of Queensland, QLD 4072, Australia
| | - Olivier Cheneval
- Institute for Molecular Bioscience, The University of Queensland, QLD 4072, Australia
| | - Rachel M Chen
- Institute for Molecular Bioscience, The University of Queensland, QLD 4072, Australia
| | - David J Craik
- Institute for Molecular Bioscience, The University of Queensland, QLD 4072, Australia
| | - Christina I Schroeder
- Institute for Molecular Bioscience, The University of Queensland, QLD 4072, Australia
| | - Sónia T Henriques
- Institute for Molecular Bioscience, The University of Queensland, QLD 4072, Australia.
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11
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Agwa AJ, Huang YH, Craik DJ, Henriques ST, Schroeder CI. Lengths of the C-Terminus and Interconnecting Loops Impact Stability of Spider-Derived Gating Modifier Toxins. Toxins (Basel) 2017; 9:toxins9080248. [PMID: 28805686 PMCID: PMC5577582 DOI: 10.3390/toxins9080248] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 08/08/2017] [Accepted: 08/08/2017] [Indexed: 12/30/2022] Open
Abstract
Spider gating modifier toxins (GMTs) are potent modulators of voltage-gated ion channels and have thus attracted attention as drug leads for several pathophysiological conditions. GMTs contain three disulfide bonds organized in an inhibitory cystine knot, which putatively confers them with high stability; however, thus far, there has not been a focused study to establish the stability of GMTs in physiological conditions. We examined the resistance of five GMTs including GpTx-1, HnTx-IV, HwTx-IV, PaurTx-3 and SgTx-1, to pH, thermal and proteolytic degradation. The peptides were stable under physiological conditions, except SgTx-1, which was susceptible to proteolysis, probably due to a longer C-terminus compared to the other peptides. In non-physiological conditions, the five peptides withstood chaotropic degradation, and all but SgTx-1 remained intact after prolonged exposure to high temperature; however, the peptides were degraded in strongly alkaline solutions. GpTx-1 and PaurTx-3 were more resistant to basic hydrolysis than HnTx-IV, HwTx-IV and SgTx-1, probably because a shorter interconnecting loop 3 on GpTx-1 and PaurTx-3 may stabilize interactions between the C-terminus and the hydrophobic patch. Here, we establish that most GMTs are exceptionally stable, and propose that, in the design of GMT-based therapeutics, stability can be enhanced by optimizing the C-terminus in terms of length, and increased interactions with the hydrophobic patch.
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Affiliation(s)
- Akello J Agwa
- Institute for Molecular Bioscience, the University of Queensland, Brisbane, Queensland 4072, Australia.
| | - Yen-Hua Huang
- Institute for Molecular Bioscience, the University of Queensland, Brisbane, Queensland 4072, Australia.
| | - David J Craik
- Institute for Molecular Bioscience, the University of Queensland, Brisbane, Queensland 4072, Australia.
| | - Sónia T Henriques
- Institute for Molecular Bioscience, the University of Queensland, Brisbane, Queensland 4072, Australia.
| | - Christina I Schroeder
- Institute for Molecular Bioscience, the University of Queensland, Brisbane, Queensland 4072, Australia.
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Agwa AJ, Henriques ST, Schroeder CI. Gating modifier toxin interactions with ion channels and lipid bilayers: Is the trimolecular complex real? Neuropharmacology 2017; 127:32-45. [PMID: 28400258 DOI: 10.1016/j.neuropharm.2017.04.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 03/31/2017] [Accepted: 04/05/2017] [Indexed: 11/15/2022]
Abstract
Spider peptide toxins have attracted attention because of their ability to target voltage-gated ion channels, which are involved in several pathologies including chronic pain and some cardiovascular conditions. A class of these peptides acts by modulating the gating mechanism of voltage-gated ion channels and are thus called gating modifier toxins (GMTs). In addition to their interactions with voltage-gated ion channels, some GMTs have affinity for lipid bilayers. This review discusses the potential importance of the cell membrane on the mode of action of GMTs. We propose that peptide-membrane interactions can anchor GMTs at the cell surface, thereby increasing GMT concentration in the vicinity of the channel binding site. We also propose that modulating peptide-membrane interactions might be useful for increasing the therapeutic potential of spider toxins. Furthermore, we explore the advantages and limitations of the methodologies currently used to examine peptide-membrane interactions. Although GMT-lipid membrane binding does not appear to be a requirement for the activity of all GMTs, it is an important feature, and future studies with GMTs should consider the trimolecular peptide-lipid membrane-channel complex. This article is part of the Special Issue entitled 'Venom-derived Peptides as Pharmacological Tools.'
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Affiliation(s)
- Akello J Agwa
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Sónia T Henriques
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia.
| | - Christina I Schroeder
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia.
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