1
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McMahon KL, Vetter I, Schroeder CI. Voltage-Gated Sodium Channel Inhibition by µ-Conotoxins. Toxins (Basel) 2024; 16:55. [PMID: 38251271 PMCID: PMC10819908 DOI: 10.3390/toxins16010055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 01/10/2024] [Accepted: 01/11/2024] [Indexed: 01/23/2024] Open
Abstract
µ-Conotoxins are small, potent pore-blocker inhibitors of voltage-gated sodium (NaV) channels, which have been identified as pharmacological probes and putative leads for analgesic development. A limiting factor in their therapeutic development has been their promiscuity for different NaV channel subtypes, which can lead to undesirable side-effects. This review will focus on four areas of µ-conotoxin research: (1) mapping the interactions of µ-conotoxins with different NaV channel subtypes, (2) µ-conotoxin structure-activity relationship studies, (3) observed species selectivity of µ-conotoxins and (4) the effects of µ-conotoxin disulfide connectivity on activity. Our aim is to provide a clear overview of the current status of µ-conotoxin research.
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Affiliation(s)
- Kirsten L. McMahon
- Institute for Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Irina Vetter
- Institute for Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
- The School of Pharmacy, The University of Queensland, Woolloongabba, QLD 4102, Australia
| | - Christina I. Schroeder
- Institute for Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
- Genentech, 1 DNA Way, South San Francisco, CA 94080, USA
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2
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McMahon KL, O'Brien H, Schroeder CI, Deuis JR, Venkatachalam D, Huang D, Green BR, Bandyopadhyay PK, Li Q, Yandell M, Safavi-Hemami H, Olivera BM, Vetter I, Robinson SD. Identification of sodium channel toxins from marine cone snails of the subgenera Textilia and Afonsoconus. Cell Mol Life Sci 2023; 80:287. [PMID: 37689602 PMCID: PMC10492761 DOI: 10.1007/s00018-023-04935-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 08/20/2023] [Accepted: 08/22/2023] [Indexed: 09/11/2023]
Abstract
Voltage-gated sodium (NaV) channels are transmembrane proteins that play a critical role in electrical signaling in the nervous system and other excitable tissues. µ-Conotoxins are peptide toxins from the venoms of marine cone snails (genus Conus) that block NaV channels with nanomolar potency. Most species of the subgenera Textilia and Afonsoconus are difficult to acquire; therefore, their venoms have yet to be comprehensively interrogated for µ-conotoxins. The goal of this study was to find new µ-conotoxins from species of the subgenera Textilia and Afonsoconus and investigate their selectivity at human NaV channels. Using RNA-seq of the venom gland of Conus (Textilia) bullatus, we identified 12 µ-conotoxin (or µ-conotoxin-like) sequences. Based on these sequences we designed primers which we used to identify additional µ-conotoxin sequences from DNA extracted from historical specimens of species from Textilia and Afonsoconus. We synthesized six of these µ-conotoxins and tested their activity on human NaV1.1-NaV1.8. Five of the six synthetic peptides were potent blockers of human NaV channels. Of these, two peptides (BuIIIB and BuIIIE) were potent blockers of hNaV1.3. Three of the peptides (BuIIIB, BuIIIE and AdIIIA) had submicromolar activity at hNaV1.7. This study serves as an example of the identification of new peptide toxins from historical DNA and provides new insights into structure-activity relationships of µ-conotoxins with activity at hNaV1.3 and hNaV1.7.
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Affiliation(s)
- Kirsten L McMahon
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Henrik O'Brien
- Biology Department, University of Utah, Salt Lake City, UT, 84112, USA
| | - Christina I Schroeder
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
- Peptide Therapeutics, Genentech, 1 DNA Way, South San Francisco, CA, 94080, USA
| | - Jennifer R Deuis
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | | | - Di Huang
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Brad R Green
- Biology Department, University of Utah, Salt Lake City, UT, 84112, USA
| | | | - Qing Li
- Department of Human Genetics, Utah Center for Genetic Discovery, University of Utah, Salt Lake City, UT, 84112, USA
- Cancer Bioinformatics, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, 84112, USA
| | - Mark Yandell
- Department of Human Genetics, Utah Center for Genetic Discovery, University of Utah, Salt Lake City, UT, 84112, USA
| | | | | | - Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Samuel D Robinson
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia.
- Biology Department, University of Utah, Salt Lake City, UT, 84112, USA.
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3
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Groome JR. Historical Perspective of the Characterization of Conotoxins Targeting Voltage-Gated Sodium Channels. Mar Drugs 2023; 21:md21040209. [PMID: 37103349 PMCID: PMC10142487 DOI: 10.3390/md21040209] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 03/21/2023] [Accepted: 03/24/2023] [Indexed: 03/30/2023] Open
Abstract
Marine toxins have potent actions on diverse sodium ion channels regulated by transmembrane voltage (voltage-gated ion channels) or by neurotransmitters (nicotinic acetylcholine receptor channels). Studies of these toxins have focused on varied aspects of venom peptides ranging from evolutionary relationships of predator and prey, biological actions on excitable tissues, potential application as pharmacological intervention in disease therapy, and as part of multiple experimental approaches towards an understanding of the atomistic characterization of ion channel structure. This review examines the historical perspective of the study of conotoxin peptides active on sodium channels gated by transmembrane voltage, which has led to recent advances in ion channel research made possible with the exploitation of the diversity of these marine toxins.
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Affiliation(s)
- James R Groome
- Department of Biological Sciences, Idaho State University, Pocatello, ID 83209, USA
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4
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McMahon KL, Tran HNT, Deuis JR, Craik DJ, Vetter I, Schroeder CI. µ-Conotoxins Targeting the Human Voltage-Gated Sodium Channel Subtype NaV1.7. Toxins (Basel) 2022; 14:toxins14090600. [PMID: 36136538 PMCID: PMC9506549 DOI: 10.3390/toxins14090600] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/25/2022] [Accepted: 08/26/2022] [Indexed: 12/03/2022] Open
Abstract
µ-Conotoxins are small, potent, peptide voltage-gated sodium (NaV) channel inhibitors characterised by a conserved cysteine framework. Despite promising in vivo studies indicating analgesic potential of these compounds, selectivity towards the therapeutically relevant subtype NaV1.7 has so far been limited. We recently identified a novel µ-conotoxin, SxIIIC, which potently inhibits human NaV1.7 (hNaV1.7). SxIIIC has high sequence homology with other µ-conotoxins, including SmIIIA and KIIIA, yet shows different NaV channel selectivity for mammalian subtypes. Here, we evaluated and compared the inhibitory potency of µ-conotoxins SxIIIC, SmIIIA and KIIIA at hNaV channels by whole-cell patch-clamp electrophysiology and discovered that these three closely related µ-conotoxins display unique selectivity profiles with significant variations in inhibitory potency at hNaV1.7. Analysis of other µ-conotoxins at hNaV1.7 shows that only a limited number are capable of inhibition at this subtype and that differences between the number of residues in loop 3 appear to influence the ability of µ-conotoxins to inhibit hNaV1.7. Through mutagenesis studies, we confirmed that charged residues in this region also affect the selectivity for hNaV1.4. Comparison of µ-conotoxin NMR solution structures identified differences that may contribute to the variance in hNaV1.7 inhibition and validated the role of the loop 1 extension in SxIIIC for improving potency at hNaV1.7, when compared to KIIIA. This work could assist in designing µ-conotoxin derivatives specific for hNaV1.7.
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Affiliation(s)
- Kirsten L. McMahon
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Hue N. T. Tran
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Jennifer R. Deuis
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - David J. Craik
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
- The School of Pharmacy, The University of Queensland, Woolloongabba, QLD 4102, Australia
- Correspondence: (I.V.); (C.I.S.)
| | - Christina I. Schroeder
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
- Correspondence: (I.V.); (C.I.S.)
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Tran HNT, McMahon KL, Deuis JR, Vetter I, Schroeder CI. Structural and functional insights into the inhibition of human voltage-gated sodium channels by μ-conotoxin KIIIA disulfide isomers. J Biol Chem 2022; 298:101728. [PMID: 35167877 PMCID: PMC8927997 DOI: 10.1016/j.jbc.2022.101728] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 02/08/2022] [Accepted: 02/11/2022] [Indexed: 12/13/2022] Open
Abstract
μ-Conotoxins are components of cone snail venom, well-known for their analgesic activity through potent inhibition of voltage-gated sodium channel (NaV) subtypes, including NaV1.7. These small, disulfide-rich peptides are typically stabilized by three disulfide bonds arranged in a ‘native’ CysI-CysIV, CysII-CysV, CysIII-CysVI pattern of disulfide connectivity. However, μ-conotoxin KIIIA, the smallest and most studied μ-conotoxin with inhibitory activity at NaV1.7, forms two distinct disulfide bond isomers during thermodynamic oxidative folding, including Isomer 1 (CysI-CysV, CysII-CysIV, CysIII-CysVI) and Isomer 2 (CysI-CysVI, CysII-CysIV, CysIII-CysV), but not the native μ-conotoxin arrangement. To date, there has been no study on the structure and activity of KIIIA comprising the native μ-conotoxin disulfide bond arrangement. Here, we evaluated the synthesis, potency, sodium channel subtype selectivity, and 3D structure of the three isomers of KIIIA. Using a regioselective disulfide bond-forming strategy, we synthetically produced the three μ-conotoxin KIIIA isomers displaying distinct bioactivity and NaV subtype selectivity across human NaV channel subtypes 1.2, 1.4, and 1.7. We show that Isomer 1 inhibits NaV subtypes with a rank order of potency of NaV1.4 > 1.2 > 1.7 and Isomer 2 in the order of NaV1.4≈1.2 > 1.7, while the native isomer inhibited NaV1.4 > 1.7≈1.2. The three KIIIA isomers were further evaluated by NMR solution structure analysis and molecular docking with hNaV1.2. Our study highlights the importance of investigating alternate disulfide isomers, as disulfide connectivity affects not only the overall structure of the peptides but also the potency and subtype selectivity of μ-conotoxins targeting therapeutically relevant NaV subtypes.
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Affiliation(s)
- Hue N T Tran
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
| | - Kirsten L McMahon
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
| | - Jennifer R Deuis
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
| | - Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia; School of Pharmacy, The University of Queensland, Woolloongabba, Queensland, Australia.
| | - Christina I Schroeder
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia; Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland, USA.
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6
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Jimenez EC. Post-translationally modified conopeptides: Biological activities and pharmacological applications. Peptides 2021; 139:170525. [PMID: 33684482 DOI: 10.1016/j.peptides.2021.170525] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/20/2021] [Accepted: 02/24/2021] [Indexed: 10/25/2022]
Abstract
Conus venoms comprise a large variety of biologically active peptides (conopeptides or conotoxins) that are employed for prey capture and other biological functions. Throughout the course of evolution of the cone snails, they have developed an envenomation scheme that necessitates a potent mixture of peptides, most of which are highly post-translationally modified, that can cause rapid paralysis of their prey. The great diversity of these peptides defines the ecological interactions and evolutionary strategy of cone snails. Such scheme has led to some pharmacological applications for pain, epilepsy, and myocardial infarction, that could be further explored to ultimately find unique peptide-based therapies. This review focuses on ∼ 60 representative post-translationally modified conopeptides that were isolated from Conus venoms. Various conopeptides reveal post-translational modifications of specific amino acids, such as hydroxylation of proline and lysine, gamma-carboxylation of glutamate, formation of N-terminal pyroglutamate, isomerization of l- to d-amino acid, bromination of tryptophan, O-glycosylation of threonine or serine, sulfation of tyrosine, and cysteinylation of cysteine, other than the more common disulfide crosslinking and C-terminal amidation. Many of the post-translationally modified peptides paved the way for the characterization, by alternative analytical methods, of other pharmacologically important peptides that are classified under 27 conopeptide families denoting pharmacological classes.
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Affiliation(s)
- Elsie C Jimenez
- Department of Physical Sciences, College of Science, University of the Philippines Baguio, Baguio City, 2600, Philippines.
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7
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Yang M, Zhou M. μ-conotoxin TsIIIA, a peptide inhibitor of human voltage-gated sodium channel hNa v1.8. Toxicon 2020; 186:29-34. [PMID: 32758497 DOI: 10.1016/j.toxicon.2020.07.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 07/19/2020] [Accepted: 07/22/2020] [Indexed: 10/23/2022]
Abstract
TsIIIA, the first μ-conotoxin from Conus tessulatus, can selectively inhibit rat tetrodotoxin-resistant sodium channels. TsIIIA also shows potent analgesic activity in a mice hotplate analgesic assay, but its effect on human sodium channels remains unknown. In this study, eight human sodium channel subtypes, hNav1.1- hNav1.8, were expressed in HEK293 or ND7/23 cells and tested on the chemically synthesized TsIIIA. Patch clamp experiments showed that 10 μM TsIIIA had no effects on the tetrodotoxin-sensitive hNav1.1, hNav1.2, hNav1.3, hNav1.4, hNav1.6 and hNav1.7, as well as tetrodotoxin-resistant hNav1.5. For tetrodotoxin-resistant hNav1.8, concentrations of 1, 5 and 10 μM TsIIIA reduced the hNav1.8 currents to 59.26%, 36.21% and 24.93% respectively. Further detailed dose-effect experiments showed that TsIIIA inhibited hNav1.8 currents with an IC50 value of 2.11 μM. In addition, 2 μM TsIIIA did not induce a shift in the current-voltage relationship of hNav1.8. Taken together, the hNav1.8 peptide inhibitor TsIIIA provides a pharmacological probe for sodium channels and a potential therapeutic agent for pain.
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Affiliation(s)
- Manyi Yang
- Department of Hepatobiliary and Pancreatic Surgery, NHC Key Laboratory of Nanobiological Technology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Maojun Zhou
- Department of Oncology, State Local Joint Engineering Laboratory for Anticancer Drugs, NHC Key Laboratory of Cancer Proteomics, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China.
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8
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McMahon KL, Tran HN, Deuis JR, Lewis RJ, Vetter I, Schroeder CI. Discovery, Pharmacological Characterisation and NMR Structure of the Novel µ-Conotoxin SxIIIC, a Potent and Irreversible Na V Channel Inhibitor. Biomedicines 2020; 8:biomedicines8100391. [PMID: 33023152 PMCID: PMC7599555 DOI: 10.3390/biomedicines8100391] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 09/25/2020] [Accepted: 09/29/2020] [Indexed: 12/19/2022] Open
Abstract
Voltage-gated sodium (NaV) channel subtypes, including NaV1.7, are promising targets for the treatment of neurological diseases, such as chronic pain. Cone snail-derived µ-conotoxins are small, potent NaV channel inhibitors which represent potential drug leads. Of the 22 µ-conotoxins characterised so far, only a small number, including KIIIA and CnIIIC, have shown inhibition against human NaV1.7. We have recently identified a novel µ-conotoxin, SxIIIC, from Conus striolatus. Here we present the isolation of native peptide, chemical synthesis, characterisation of human NaV channel activity by whole-cell patch-clamp electrophysiology and analysis of the NMR solution structure. SxIIIC displays a unique NaV channel selectivity profile (1.4 > 1.3 > 1.1 ≈ 1.6 ≈ 1.7 > 1.2 >> 1.5 ≈ 1.8) when compared to other µ-conotoxins and represents one of the most potent human NaV1.7 putative pore blockers (IC50 152.2 ± 21.8 nM) to date. NMR analysis reveals the structure of SxIIIC includes the characteristic α-helix seen in other µ-conotoxins. Future investigations into structure-activity relationships of SxIIIC are expected to provide insights into residues important for NaV channel pore blocker selectivity and subsequently important for chronic pain drug development.
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Affiliation(s)
- Kirsten L. McMahon
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia; (K.L.M.); (H.N.T.T.); (J.R.D.); (R.J.L.)
| | - Hue N.T. Tran
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia; (K.L.M.); (H.N.T.T.); (J.R.D.); (R.J.L.)
| | - Jennifer R. Deuis
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia; (K.L.M.); (H.N.T.T.); (J.R.D.); (R.J.L.)
| | - Richard J. Lewis
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia; (K.L.M.); (H.N.T.T.); (J.R.D.); (R.J.L.)
| | - Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia; (K.L.M.); (H.N.T.T.); (J.R.D.); (R.J.L.)
- The School of Pharmacy, The University of Queensland, Woolloongabba, QLD 4102, Australia
- Correspondence: (I.V.); (C.I.S.)
| | - Christina I. Schroeder
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia; (K.L.M.); (H.N.T.T.); (J.R.D.); (R.J.L.)
- National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
- Correspondence: (I.V.); (C.I.S.)
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9
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Paul George AA, Heimer P, Maaß A, Hamaekers J, Hofmann-Apitius M, Biswas A, Imhof D. Insights into the Folding of Disulfide-Rich μ-Conotoxins. ACS OMEGA 2018; 3:12330-12340. [PMID: 30411002 PMCID: PMC6217517 DOI: 10.1021/acsomega.8b01465] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 09/12/2018] [Indexed: 06/08/2023]
Abstract
The study of protein conformations using molecular dynamics (MD) simulations has been in place for decades. A major contribution to the structural stability and native conformation of a protein is made by the primary sequence and disulfide bonds formed during the folding process. Here, we investigated μ-conotoxins GIIIA, KIIIA, PIIIA, SIIIA, and SmIIIA as model peptides possessing three disulfide bonds. Their NMR structures were used for MD simulations in a novel approach studying the conformations between the folded and the unfolded states by systematically breaking the distinct disulfide bonds and monitoring the conformational stability of the peptides. As an outcome, the use of a combination of the existing knowledge and results from the simulations to classify the studied peptides within the extreme models of disulfide folding pathways, namely the bovine pancreatic trypsin inhibitor pathway and the hirudin pathway, is demonstrated. Recommendations for the design and synthesis of cysteine-rich peptides with a reduced number of disulfide bonds conclude the study.
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Affiliation(s)
- Ajay Abisheck Paul George
- Pharmaceutical
Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
| | - Pascal Heimer
- Pharmaceutical
Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
| | - Astrid Maaß
- Department
of Virtual Material Design and Department of Bioinformatics, Fraunhofer Institute for Algorithms and Scientific
Computing, Schloss Birlinghoven, D-53754 Sankt Augustin, Germany
| | - Jan Hamaekers
- Department
of Virtual Material Design and Department of Bioinformatics, Fraunhofer Institute for Algorithms and Scientific
Computing, Schloss Birlinghoven, D-53754 Sankt Augustin, Germany
| | - Martin Hofmann-Apitius
- Department
of Virtual Material Design and Department of Bioinformatics, Fraunhofer Institute for Algorithms and Scientific
Computing, Schloss Birlinghoven, D-53754 Sankt Augustin, Germany
- Bonn-Aachen
International Center for Information Technology, University of Bonn, Endenicher Allee 19 C, D-53115 Bonn, Germany
| | - Arijit Biswas
- Institute
for Experimental Hematology, University
Hospital Bonn, Sigmund-Freud-Straße
25, D-53127 Bonn, Germany
| | - Diana Imhof
- Pharmaceutical
Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
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10
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Vijayasarathy M, Basheer SM, Balaram P. Cone Snail Glutaminyl Cyclase Sequences from Transcriptomic Analysis and Mass Spectrometric Characterization of Two Pyroglutamyl Conotoxins. J Proteome Res 2018; 17:2695-2703. [DOI: 10.1021/acs.jproteome.8b00132] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Marimuthu Vijayasarathy
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore 560065, India
| | - Soorej M. Basheer
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India
- Department of Molecular Biology, Kannur University, Nileshwaram Campus, Kasargod 671314, Kerala, India
| | - Padmanabhan Balaram
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore 560065, India
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11
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Cardoso FC, Lewis RJ. Sodium channels and pain: from toxins to therapies. Br J Pharmacol 2018; 175:2138-2157. [PMID: 28749537 PMCID: PMC5980290 DOI: 10.1111/bph.13962] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 07/11/2017] [Accepted: 07/17/2017] [Indexed: 12/16/2022] Open
Abstract
Voltage-gated sodium channels (NaV channels) are essential for the initiation and propagation of action potentials that critically influence our ability to respond to a diverse range of stimuli. Physiological and pharmacological studies have linked abnormal function of NaV channels to many human disorders, including chronic neuropathic pain. These findings, along with the description of the functional properties and expression pattern of NaV channel subtypes, are helping to uncover subtype specific roles in acute and chronic pain and revealing potential opportunities to target these with selective inhibitors. High-throughput screens and automated electrophysiology platforms have identified natural toxins as a promising group of molecules for the development of target-specific analgesics. In this review, the role of toxins in defining the contribution of NaV channels in acute and chronic pain states and their potential to be used as analgesic therapies are discussed. LINKED ARTICLES This article is part of a themed section on Recent Advances in Targeting Ion Channels to Treat Chronic Pain. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.12/issuetoc.
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Affiliation(s)
- Fernanda C Cardoso
- Department of Chemistry and Structural Biology, Institute for Molecular BioscienceThe University of QueenslandBrisbaneQLDAustralia
| | - Richard J Lewis
- Department of Chemistry and Structural Biology, Institute for Molecular BioscienceThe University of QueenslandBrisbaneQLDAustralia
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12
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Wu X, Huang Y, Kaas Q, Craik DJ. Cyclisation of Disulfide‐Rich Conotoxins in Drug Design Applications. European J Org Chem 2016. [DOI: 10.1002/ejoc.201600402] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Xiaosa Wu
- Institute for Molecular BioscienceThe University of Queensland306 Carmody Road (Building 80)4072BrisbaneAustralia
| | - Yen‐Hua Huang
- Institute for Molecular BioscienceThe University of Queensland306 Carmody Road (Building 80)4072BrisbaneAustralia
| | - Quentin Kaas
- Institute for Molecular BioscienceThe University of Queensland306 Carmody Road (Building 80)4072BrisbaneAustralia
| | - David J. Craik
- Institute for Molecular BioscienceThe University of Queensland306 Carmody Road (Building 80)4072BrisbaneAustralia
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13
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Munasinghe NR, Christie MJ. Conotoxins That Could Provide Analgesia through Voltage Gated Sodium Channel Inhibition. Toxins (Basel) 2015; 7:5386-407. [PMID: 26690478 PMCID: PMC4690140 DOI: 10.3390/toxins7124890] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 10/23/2015] [Accepted: 11/19/2015] [Indexed: 12/19/2022] Open
Abstract
Chronic pain creates a large socio-economic burden around the world. It is physically and mentally debilitating, and many sufferers are unresponsive to current therapeutics. Many drugs that provide pain relief have adverse side effects and addiction liabilities. Therefore, a great need has risen for alternative treatment strategies. One rich source of potential analgesic compounds that has emerged over the past few decades are conotoxins. These toxins are extremely diverse and display selective activity at ion channels. Voltage gated sodium (NaV) channels are one such group of ion channels that play a significant role in multiple pain pathways. This review will explore the literature around conotoxins that bind NaV channels and determine their analgesic potential.
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Affiliation(s)
- Nehan R Munasinghe
- Discipline of Pharmacology, The University of Sydney, Sydney, NSW 2006, Australia.
| | - MacDonald J Christie
- Discipline of Pharmacology, The University of Sydney, Sydney, NSW 2006, Australia.
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14
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Structure and function of μ-conotoxins, peptide-based sodium channel blockers with analgesic activity. Future Med Chem 2015; 6:1677-98. [PMID: 25406007 DOI: 10.4155/fmc.14.107] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
μ-Conotoxins block voltage-gated sodium channels (VGSCs) and compete with tetrodotoxin for binding to the sodium conductance pore. Early efforts identified µ-conotoxins that preferentially blocked the skeletal muscle subtype (NaV1.4). However, the last decade witnessed a significant increase in the number of µ-conotoxins and the range of VGSC subtypes inhibited (NaV1.2, NaV1.3 or NaV1.7). Twenty µ-conotoxin sequences have been identified to date and structure-activity relationship studies of several of these identified key residues responsible for interactions with VGSC subtypes. Efforts to engineer-in subtype specificity are driven by in vivo analgesic and neuromuscular blocking activities. This review summarizes structural and pharmacological studies of µ-conotoxins, which show promise for development of selective blockers of NaV1.2, and perhaps also NaV1.1,1.3 or 1.7.
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15
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Akondi KB, Muttenthaler M, Dutertre S, Kaas Q, Craik DJ, Lewis RJ, Alewood PF. Discovery, synthesis, and structure-activity relationships of conotoxins. Chem Rev 2014; 114:5815-47. [PMID: 24720541 PMCID: PMC7610532 DOI: 10.1021/cr400401e] [Citation(s) in RCA: 232] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
| | | | - Sébastien Dutertre
- Institute for Molecular Bioscience, The University of Queensland, Brisbane QLD 4072, Australia
| | - Quentin Kaas
- Institute for Molecular Bioscience, The University of Queensland, Brisbane QLD 4072, Australia
| | - David J Craik
- Institute for Molecular Bioscience, The University of Queensland, Brisbane QLD 4072, Australia
| | - Richard J Lewis
- Institute for Molecular Bioscience, The University of Queensland, Brisbane QLD 4072, Australia
| | - Paul F Alewood
- Institute for Molecular Bioscience, The University of Queensland, Brisbane QLD 4072, Australia
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16
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Green BR, Zhang MM, Chhabra S, Robinson SD, Wilson MJ, Redding A, Olivera BM, Yoshikami D, Bulaj G, Norton RS. Interactions of disulfide-deficient selenocysteine analogs of μ-conotoxin BuIIIB with the α-subunit of the voltage-gated sodium channel subtype 1.3. FEBS J 2014; 281:2885-98. [PMID: 24814369 DOI: 10.1111/febs.12835] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 04/18/2014] [Accepted: 05/05/2014] [Indexed: 12/17/2022]
Abstract
Inhibitors of the α-subunit of the voltage-gated sodium channel subtype 1.3 (NaV 1.3) are of interest as pharmacological tools for the study of neuropathic pain associated with spinal cord injury and have potential therapeutic applications. The recently described μ-conotoxin BuIIIB (μ-BuIIIB) from Conus bullatus was shown to block NaV 1.3 with submicromolar potency (Kd = 0.2 μm), making it one of the most potent peptidic inhibitors of this subtype described to date. However, oxidative folding of μ-BuIIIB results in numerous folding isoforms, making it difficult to obtain sufficient quantities of the active form of the peptide for detailed structure-activity studies. In the present study, we report the synthesis and characterization of μ-BuIIIB analogs incorporating a disulfide-deficient, diselenide-containing scaffold designed to simplify synthesis and facilitate structure-activity studies directed at identifying amino acid residues involved in NaV 1.3 blockade. Our results indicate that, similar to other μ-conotoxins, the C-terminal residues (Trp16, Arg18 and His20) are most crucial for NaV 1 blockade. At the N-terminus, replacement of Glu3 by Ala resulted in an analog with an increased potency for NaV 1.3 (Kd = 0.07 μm), implicating this position as a potential site for modification for increased potency and/or selectivity. Further examination of this position showed that increased negative charge, through γ-carboxyglutamate replacement, decreased potency (Kd = 0.33 μm), whereas replacement with positively-charged 2,4-diamonobutyric acid increased potency (Kd = 0.036 μm). These results provide a foundation for the design and synthesis of μ-BuIIIB-based analogs with increased potency against NaV 1.3.
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Affiliation(s)
- Brad R Green
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Vic., Australia; Department of Medicinal Chemistry, College of Pharmacy, University of Utah, Salt Lake City, UT, USA
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17
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Nguyen B, Caer JPL, Mourier G, Thai R, Lamthanh H, Servent D, Benoit E, Molgó J. Characterization of a novel Conus bandanus conopeptide belonging to the M-superfamily containing bromotryptophan. Mar Drugs 2014; 12:3449-65. [PMID: 24905483 PMCID: PMC4071585 DOI: 10.3390/md12063449] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Revised: 03/07/2014] [Accepted: 05/22/2014] [Indexed: 01/29/2023] Open
Abstract
A novel conotoxin (conopeptide) was biochemically characterized from the crude venom of the molluscivorous marine snail, Conus bandanus (Hwass in Bruguière, 1792), collected in the south-central coast of Vietnam. The peptide was identified by screening bromotryptophan from chromatographic fractions of the crude venom. Tandem mass spectrometry techniques were used to detect and localize different post-translational modifications (PTMs) present in the BnIIID conopeptide. The sequence was confirmed by Edman’s degradation and mass spectrometry revealing that the purified BnIIID conopeptide had 15 amino acid residues, with six cysteines at positions 1, 2, 7, 11, 13, and 14, and three PTMs: bromotryptophan, γ-carboxy glutamate, and amidated aspartic acid, at positions “4”, “5”, and “15”, respectively. The BnIIID peptide was synthesized for comparison with the native peptide. Homology comparison with conopeptides having the III-cysteine framework (–CCx1x2x3x4Cx1x2x3Cx1CC–) revealed that BnIIID belongs to the M-1 family of conotoxins. This is the first report of a member of the M-superfamily containing bromotryptophan as PTM.
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Affiliation(s)
- Bao Nguyen
- Neurobiology and Development Laboratory, Research Unit # 3294, Institute of Neurobiology Alfred Fessard # 2118, National Center for Scientific Research, Gif sur Yvette Cedex 91198, France.
| | - Jean-Pierre Le Caer
- Research Unit # 2301, Natural Product Chemistry Institute, National Center for Scientific Research, Gif sur Yvette Cedex 91198, France.
| | - Gilles Mourier
- Molecular Engineering of Proteins, Institute of Biology and Technology Saclay, Atomic Energy Commission, Gif sur Yvette Cedex 91191, France.
| | - Robert Thai
- Molecular Engineering of Proteins, Institute of Biology and Technology Saclay, Atomic Energy Commission, Gif sur Yvette Cedex 91191, France.
| | - Hung Lamthanh
- Neurobiology and Development Laboratory, Research Unit # 3294, Institute of Neurobiology Alfred Fessard # 2118, National Center for Scientific Research, Gif sur Yvette Cedex 91198, France.
| | - Denis Servent
- Molecular Engineering of Proteins, Institute of Biology and Technology Saclay, Atomic Energy Commission, Gif sur Yvette Cedex 91191, France.
| | - Evelyne Benoit
- Neurobiology and Development Laboratory, Research Unit # 3294, Institute of Neurobiology Alfred Fessard # 2118, National Center for Scientific Research, Gif sur Yvette Cedex 91198, France.
| | - Jordi Molgó
- Neurobiology and Development Laboratory, Research Unit # 3294, Institute of Neurobiology Alfred Fessard # 2118, National Center for Scientific Research, Gif sur Yvette Cedex 91198, France.
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18
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Lebbe EKM, Peigneur S, Brullot W, Verbiest T, Tytgat J. Ala-7, His-10 and Arg-12 are crucial amino acids for activity of a synthetically engineered μ-conotoxin. Peptides 2014; 53:300-6. [PMID: 23871692 DOI: 10.1016/j.peptides.2013.07.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 07/01/2013] [Accepted: 07/01/2013] [Indexed: 12/19/2022]
Abstract
Cone snail toxins or conotoxins are often small cysteine-rich peptides which have shown to be highly selective ligands for a wide range of ion channels such as voltage-gated sodium channels (Na(V)s). Na(V)s participate in a wide range of electrophysiological processes. Consequently, their malfunction has been associated with numerous diseases. The development of subtype-selective modulators of Na(V)s remains highly important in the treatment of such disorders. In order to expand our knowledge in the search for novel therapeutics to treat Na(V)-related diseases, we explored the field of peptide engineering. In the current study, the impact of well considered point mutations into a bioactive peptide that was found to be a very potent and selective inhibitor of Na(V)s (i.e. Midi R2) was examined. We designed two peptides, named Midi R2[A7G] and Midi R2[H10A, R12A] which have mutations at position 7, and both 10 and 12, respectively. Electrophysiological recordings indicated that an Ala to Gly mutation at position 7 increased IC50-values from the nanomolar range to the micromolar range. For Midi R2[H10A, R12A] at a concentration of 10 μM, activity is even reduced to 0-10% for all of the tested Na(V)-channels. Circular dichroism measurements proved that overall structural conformations did not change. These findings suggest that the minimal space between the second and the third intercysteine loop of Midi R2 is the sequence RRWARDHSR and that His at position 10 and Arg at position 12 are crucial amino acids for the potency and specificity of Midi R2. In this way, new insights into the structure-activity relationships of μ-conotoxins were found.
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Affiliation(s)
- Eline K M Lebbe
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg O&N2, Herestraat 49, P.O. Box 922, 3000 Leuven, Belgium.
| | - Steve Peigneur
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg O&N2, Herestraat 49, P.O. Box 922, 3000 Leuven, Belgium.
| | - Ward Brullot
- Laboratory for Molecular Electronics and Photonics, Division Molecular Imaging and Photonics, Department of Chemistry, University of Leuven, Celestijnenlaan 200D, P.O. Box 2425, 3001 Heverlee, Belgium.
| | - Thierry Verbiest
- Laboratory for Molecular Electronics and Photonics, Division Molecular Imaging and Photonics, Department of Chemistry, University of Leuven, Celestijnenlaan 200D, P.O. Box 2425, 3001 Heverlee, Belgium.
| | - Jan Tytgat
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg O&N2, Herestraat 49, P.O. Box 922, 3000 Leuven, Belgium.
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Miniaturized bioaffinity assessment coupled to mass spectrometry for guided purification of bioactives from toad and cone snail. BIOLOGY 2014; 3:139-56. [PMID: 24833338 PMCID: PMC4009767 DOI: 10.3390/biology3010139] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 01/23/2014] [Accepted: 01/26/2014] [Indexed: 11/17/2022]
Abstract
A nano-flow high-resolution screening platform, featuring a parallel chip-based microfluidic bioassay and mass spectrometry coupled to nano-liquid chromatography, was applied to screen animal venoms for nicotinic acetylcholine receptor like (nAChR) affinity by using the acetylcholine binding protein, a mimic of the nAChR. The potential of this microfluidic platform is demonstrated by profiling the Conus textile venom proteome, consisting of over 1,000 peptides. Within one analysis (<90 min, 500 ng venom injected), ligands are detected and identified. To show applicability for non-peptides, small molecular ligands such as steroidal ligands were identified in skin secretions from two toad species (Bufo alvarius and Bufo marinus). Bioactives from the toad samples were subsequently isolated by MS-guided fractionation. The fractions analyzed by NMR and a radioligand binding assay with α7-nAChR confirmed the identity and bioactivity of several new ligands.
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20
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Akondi KB, Lewis RJ, Alewood PF. Re-engineering the μ-conotoxin SIIIA scaffold. Biopolymers 2014; 101:347-54. [DOI: 10.1002/bip.22368] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 07/21/2013] [Accepted: 07/26/2013] [Indexed: 12/19/2022]
Affiliation(s)
- K. B. Akondi
- Institute for Molecular Bioscience (IMB); The University of Queensland; Brisbane 4072 Queensland Australia
| | - R. J. Lewis
- Institute for Molecular Bioscience (IMB); The University of Queensland; Brisbane 4072 Queensland Australia
| | - P. F. Alewood
- Institute for Molecular Bioscience (IMB); The University of Queensland; Brisbane 4072 Queensland Australia
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21
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Bergeron ZL, Chun JB, Baker MR, Sandall DW, Peigneur S, Yu PY, Thapa P, Milisen JW, Tytgat J, Livett BG, Bingham JP. A 'conovenomic' analysis of the milked venom from the mollusk-hunting cone snail Conus textile--the pharmacological importance of post-translational modifications. Peptides 2013; 49:145-58. [PMID: 24055806 PMCID: PMC6013274 DOI: 10.1016/j.peptides.2013.09.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 09/08/2013] [Accepted: 09/09/2013] [Indexed: 12/19/2022]
Abstract
Cone snail venoms provide a largely untapped source of novel peptide drug leads. To enhance the discovery phase, a detailed comparative proteomic analysis was undertaken on milked venom from the mollusk-hunting cone snail, Conus textile, from three different geographic locations (Hawai'i, American Samoa and Australia's Great Barrier Reef). A novel milked venom conopeptide rich in post-translational modifications was discovered, characterized and named α-conotoxin TxIC. We assign this conopeptide to the 4/7 α-conotoxin family based on the peptide's sequence homology and cDNA pre-propeptide alignment. Pharmacologically, α-conotoxin TxIC demonstrates minimal activity on human acetylcholine receptor models (100 μM, <5% inhibition), compared to its high paralytic potency in invertebrates, PD50 = 34.2 nMol kg(-1). The non-post-translationally modified form, [Pro](2,8)[Glu](16)α-conotoxin TxIC, demonstrates differential selectivity for the α3β2 isoform of the nicotinic acetylcholine receptor with maximal inhibition of 96% and an observed IC50 of 5.4 ± 0.5 μM. Interestingly its comparative PD50 (3.6 μMol kg(-1)) in invertebrates was ~100 fold more than that of the native peptide. Differentiating α-conotoxin TxIC from other α-conotoxins is the high degree of post-translational modification (44% of residues). This includes the incorporation of γ-carboxyglutamic acid, two moieties of 4-trans hydroxyproline, two disulfide bond linkages, and C-terminal amidation. These findings expand upon the known chemical diversity of α-conotoxins and illustrate a potential driver of toxin phyla-selectivity within Conus.
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Affiliation(s)
- Zachary L. Bergeron
- Department of Molecular Biosciences and Bioengineering, University of Hawai'i, Honolulu, HI, USA, 96822
| | - Joycelyn B. Chun
- Department of Molecular Biosciences and Bioengineering, University of Hawai'i, Honolulu, HI, USA, 96822
| | - Margaret R. Baker
- Department of Molecular Biosciences and Bioengineering, University of Hawai'i, Honolulu, HI, USA, 96822
| | - David W. Sandall
- Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Parkville, Victoria, Australia, 3010
| | - Steve Peigneur
- Laboratory of Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg O&N II, Leuven, Belgium, 3000
| | - Peter Y.C. Yu
- Department of Molecular Biosciences and Bioengineering, University of Hawai'i, Honolulu, HI, USA, 96822
| | - Parashar Thapa
- Department of Molecular Biosciences and Bioengineering, University of Hawai'i, Honolulu, HI, USA, 96822
| | - Jeffrey W. Milisen
- Department of Molecular Biosciences and Bioengineering, University of Hawai'i, Honolulu, HI, USA, 96822
| | - Jan Tytgat
- Laboratory of Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg O&N II, Leuven, Belgium, 3000
| | - Bruce G. Livett
- Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Parkville, Victoria, Australia, 3010
| | - Jon-Paul Bingham
- Department of Molecular Biosciences and Bioengineering, University of Hawai'i, Honolulu, HI, USA, 96822
- Corresponding Author: Dr. Jon-Paul Bingham, , Fax: (808) 965-3542, Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai'i, HI, 96822, USA
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22
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Abstract
Conopeptides from the venoms of marine snails have attracted much interest as leads in drug design. Currently, one drug, Prialt(®), is on the market as a treatment for chronic neuropathic pain. Conopeptides target a range of ion channels, receptors and transporters, and are typically small, relatively stable peptides that are generally amenable to production using solid-phase peptide synthesis. With only a small fraction of the predicted diversity of conopeptides examined so far, these peptides represent an exciting and largely untapped resource for drug discovery. Recent efforts at chemically re-engineering conopeptides to improve their biopharmaceutical properties promise to accelerate the translation of these fascinating marine peptides to the clinic.
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23
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Favreau P, Benoit E, Hocking HG, Carlier L, D' hoedt D, Leipold E, Markgraf R, Schlumberger S, Córdova MA, Gaertner H, Paolini-Bertrand M, Hartley O, Tytgat J, Heinemann SH, Bertrand D, Boelens R, Stöcklin R, Molgó J. A novel µ-conopeptide, CnIIIC, exerts potent and preferential inhibition of NaV1.2/1.4 channels and blocks neuronal nicotinic acetylcholine receptors. Br J Pharmacol 2012; 166:1654-68. [PMID: 22229737 DOI: 10.1111/j.1476-5381.2012.01837.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE The µ-conopeptide family is defined by its ability to block voltage-gated sodium channels (VGSCs), a property that can be used for the development of myorelaxants and analgesics. We characterized the pharmacology of a new µ-conopeptide (µ-CnIIIC) on a range of preparations and molecular targets to assess its potential as a myorelaxant. EXPERIMENTAL APPROACH µ-CnIIIC was sequenced, synthesized and characterized by its direct block of elicited twitch tension in mouse skeletal muscle and action potentials in mouse sciatic and pike olfactory nerves. µ-CnIIIC was also studied on HEK-293 cells expressing various rodent VGSCs and also on voltage-gated potassium channels and nicotinic acetylcholine receptors (nAChRs) to assess cross-interactions. Nuclear magnetic resonance (NMR) experiments were carried out for structural data. KEY RESULTS Synthetic µ-CnIIIC decreased twitch tension in mouse hemidiaphragms (IC(50) = 150 nM), and displayed a higher blocking effect in mouse extensor digitorum longus muscles (IC = 46 nM), compared with µ-SIIIA, µ-SmIIIA and µ-PIIIA. µ-CnIIIC blocked Na(V)1.4 (IC(50) = 1.3 nM) and Na(V)1.2 channels in a long-lasting manner. Cardiac Na(V)1.5 and DRG-specific Na(V)1.8 channels were not blocked at 1 µM. µ-CnIIIC also blocked the α3β2 nAChR subtype (IC(50) = 450 nM) and, to a lesser extent, on the α7 and α4β2 subtypes. Structure determination of µ-CnIIIC revealed some similarities to α-conotoxins acting on nAChRs. CONCLUSION AND IMPLICATIONS µ-CnIIIC potently blocked VGSCs in skeletal muscle and nerve, and hence is applicable to myorelaxation. Its atypical pharmacological profile suggests some common structural features between VGSCs and nAChR channels.
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Stevens M, Peigneur S, Dyubankova N, Lescrinier E, Herdewijn P, Tytgat J. Design of bioactive peptides from naturally occurring μ-conotoxin structures. J Biol Chem 2012; 287:31382-92. [PMID: 22773842 DOI: 10.1074/jbc.m112.375733] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To date, cone snail toxins ("conotoxins") are of great interest in the pursuit of novel subtype-selective modulators of voltage-gated sodium channels (Na(v)s). Na(v)s participate in a wide range of electrophysiological processes. Consequently, their malfunctioning has been associated with numerous diseases. The development of subtype-selective modulators of Na(v)s remains highly important in the treatment of such disorders. In current research, a series of novel, synthetic, and bioactive compounds were designed based on two naturally occurring μ-conotoxins that target Na(v)s. The initial designed peptide contains solely 13 amino acids and was therefore named "Mini peptide." It was derived from the μ-conotoxins KIIIA and BuIIIC. Based on this Mini peptide, 10 analogues were subsequently developed, comprising 12-16 amino acids with two disulfide bridges. Following appropriate folding and mass verification, blocking effects on Na(v)s were investigated. The most promising compound established an IC(50) of 34.1 ± 0.01 nM (R2-Midi on Na(v)1.2). An NMR structure of one of our most promising compounds was determined. Surprisingly, this structure does not reveal an α-helix. We prove that it is possible to design small peptides based on known pharmacophores of μ-conotoxins without losing their potency and selectivity. These data can provide crucial material for further development of conotoxin-based therapeutics.
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Affiliation(s)
- Marijke Stevens
- Laboratory of Toxicology, Katholieke Universiteit (KU) Leuven, Campus Gasthuisberg O and N2, Herestraat 49 Box 922, 3000 Leuven, Belgium
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25
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Conotoxins that confer therapeutic possibilities. Mar Drugs 2012; 10:1244-1265. [PMID: 22822370 PMCID: PMC3397437 DOI: 10.3390/md10061244] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 04/24/2012] [Accepted: 05/24/2012] [Indexed: 12/19/2022] Open
Abstract
Cone snails produce a distinctive repertoire of venom peptides that are used both as a defense mechanism and also to facilitate the immobilization and digestion of prey. These peptides target a wide variety of voltage- and ligand-gated ion channels, which make them an invaluable resource for studying the properties of these ion channels in normal and diseased states, as well as being a collection of compounds of potential pharmacological use in their own right. Examples include the United States Food and Drug Administration (FDA) approved pharmaceutical drug, Ziconotide (Prialt®; Elan Pharmaceuticals, Inc.) that is the synthetic equivalent of the naturally occurring ω-conotoxin MVIIA, whilst several other conotoxins are currently being used as standard research tools and screened as potential therapeutic drugs in pre-clinical or clinical trials. These developments highlight the importance of driving conotoxin-related research. A PubMed query from 1 January 2007 to 31 August 2011 combined with hand-curation of the retrieved articles allowed for the collation of 98 recently identified conotoxins with therapeutic potential which are selectively discussed in this review. Protein sequence similarity analysis tentatively assigned uncharacterized conotoxins to predicted functional classes. Furthermore, conotoxin therapeutic potential for neurodegenerative disorders (NDD) was also inferred.
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26
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Lewis RJ, Dutertre S, Vetter I, Christie MJ. Conus Venom Peptide Pharmacology. Pharmacol Rev 2012; 64:259-98. [DOI: 10.1124/pr.111.005322] [Citation(s) in RCA: 323] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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27
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Schroeder CI, Adams D, Thomas L, Alewood PF, Lewis RJ. N- and C-terminal extensions of μ-conotoxins increase potency and selectivity for neuronal sodium channels. Biopolymers 2012; 98:161-5. [PMID: 22733528 DOI: 10.1002/bip.22032] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 12/11/2011] [Accepted: 12/21/2011] [Indexed: 11/07/2022]
Abstract
μ-Conotoxins are peptide blockers of voltage-gated sodium channels (sodium channels), inhibiting tetrodotoxin-sensitive neuronal (Na(v) 1.2) and skeletal (Na(v) 1.4) subtypes with highest affinity. Structure-activity relationship studies of μ-conotoxins SIIIA, TIIIA, and KIIIA have shown that it is mainly the C-terminal part of the three-loop peptide that is involved in binding to the sodium channel. In this study, we characterize the effect of N- and C-terminal extensions of μ-conotoxins SIIIA, SIIIB, and TIIIA on their potency and selectivity for neuronal versus muscle sodium channels. Interestingly, extending the N- or C-terminal of the peptide by introducing neutral, positive, and/or negatively charged residues, the selectivity of the native peptide can be altered from neuronal to skeletal and the other way around. The results from this study provide further insight into the binding profile of μ-conotoxins at voltage-gated sodium channels, revealing that binding interactions outside the cysteine-stablilized loops can contribute to μ-conotoxin affinity and sodium channel selectivity.
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Affiliation(s)
- Christina I Schroeder
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
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28
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Leipold E, Markgraf R, Miloslavina A, Kijas M, Schirmeyer J, Imhof D, Heinemann SH. Molecular determinants for the subtype specificity of μ-conotoxin SIIIA targeting neuronal voltage-gated sodium channels. Neuropharmacology 2011; 61:105-11. [PMID: 21419143 DOI: 10.1016/j.neuropharm.2011.03.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Accepted: 03/09/2011] [Indexed: 11/29/2022]
Abstract
Voltage-gated sodium channels (Na(V) channels) play a pivotal role in neuronal excitability; they are specifically targeted by μ-conotoxins from the venom of marine cone snails. These peptide toxins bind to the outer vestibule of the channel pore thereby blocking ion conduction through Na(V) channels. μ-Conotoxin SIIIA from Conus striatus was shown to be a potent inhibitor of neuronal sodium channels and to display analgesic effects in mice, albeit the molecular targets are not unambiguously known. We therefore studied recombinant Na(V) channels expressed in mammalian cells using the whole-cell patch-clamp method. Synthetic μSIIIA slowly and partially blocked rat Na(V)1.4 channels with an apparent IC(50) of 0.56 ± 0.29 μM; the block was not complete, leaving at high concentration a residual current component of about 10% with a correspondingly reduced single-channel conductance. At 10 μM, μSIIIA potently blocked rat Na(V)1.2, rat and human Na(V)1.4, and mouse Na(V)1.6 channels; human Na(V)1.7 channels were only inhibited by 58.1 ± 4.9%, whereas human Na(V)1.5 as well as rat and human Na(V)1.8 were insensitive. Employing domain chimeras between rNa(V)1.4 and hNa(V)1.5, we located the determinants for μSIIIA specificity in the first half of the channel protein with a major contribution of domain-2 and a minor contribution of domain-1. The latter was largely accounted for by the alteration in the TTX-binding site (Tyr401 in rNa(V)1.4, Cys for Na(V)1.5, and Ser for Na(V)1.8). Introduction of domain-2 pore loops of all tested channel isoforms into rNa(V)1.4 conferred the μSIIIA phenotype of the respective donor channels highlighting the importance of the domain-2 pore loop as the major determinant for μSIIIA's subtype specificity. Single-site substitutions identified residue Ala728 in rNa(V)1.4 as crucial for its high sensitivity toward μSIIIA. Likewise, Asn889 at the homologous position in hNa(V)1.7 is responsible for the channel's reduced μSIIIA sensitivity. These results will pave the way for the rational design of selective Na(V)-channel antagonists for research and medical applications.
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Affiliation(s)
- Enrico Leipold
- Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University of Jena & University Hospital Jena, Hans-Knoell-Str. 2, D-07745 Jena, Germany
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Abstract
Venoms of snakes, scorpions, spiders, insects, sea anemones, and cone snails are complex mixtures of mostly peptides and small proteins that have evolved for prey capture and/or defense. These deadly animals have long fascinated scientists and the public. Early studies isolated lethal components in the search for cures and understanding of their mechanisms of action. Ion channels have emerged as targets for many venom peptides, providing researchers highly selective and potent molecular probes that have proved invaluable in unraveling ion channel structure and function. This minireview highlights molecular details of their toxin-receptor interactions and opportunities for development of peptide therapeutics.
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Affiliation(s)
- Sébastien Dutertre
- From Atheris Laboratories, CH-1233 Bernex-Geneva, Switzerland and
- the Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland 4067, Australia
| | - Richard J. Lewis
- the Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland 4067, Australia
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Norton RS. Mu-conotoxins as leads in the development of new analgesics. Molecules 2010; 15:2825-44. [PMID: 20428082 PMCID: PMC6257286 DOI: 10.3390/molecules15042825] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Revised: 04/06/2010] [Accepted: 04/12/2010] [Indexed: 02/02/2023] Open
Abstract
Voltage-gated sodium channels (VGSCs) contain a specific binding site for a family of cone shell toxins known as mu-conotoxins. As some VGSCs are involved in pain perception and mu-conotoxins are able to block these channels, mu-conotoxins show considerable potential as analgesics. Recent studies have advanced our understanding of the three-dimensional structures and structure-function relationships of the mu-conotoxins, including their interaction with VGSCs. Truncated peptide analogues of the native toxins have been created in which secondary structure elements are stabilized by non-native linkers such as lactam bridges. Ultimately, it would be desirable to capture the favourable analgesic properties of the native toxins, in particular their potency and channel sub-type selectivity, in non-peptide mimetics. Such mimetics would constitute lead compounds in the development of new therapeutics for the treatment of pain.
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Affiliation(s)
- Raymond S Norton
- Walter and Eliza Hall Institute of Medical Research, Victoria, Australia.
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31
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Jacob RB, McDougal OM. The M-superfamily of conotoxins: a review. Cell Mol Life Sci 2010; 67:17-27. [PMID: 19705062 PMCID: PMC3741454 DOI: 10.1007/s00018-009-0125-0] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2009] [Revised: 07/30/2009] [Accepted: 08/03/2009] [Indexed: 12/19/2022]
Abstract
The focus of this review is the M-superfamily of Conus venom peptides. Disulfide rich peptides belonging to the M-superfamily have three loop regions and the cysteine arrangement: CC-C-C-CC, where the dashes represent loops one, two, and three, respectively. Characterization of M-superfamily peptides has demonstrated that diversity in cystine connectivity occurs between different branches of peptides even though the cysteine pattern remains consistent. This superfamily is subdivided into five branches, M-1 through M-5, based on the number of residues in the third loop region, between the fourth and fifth cysteine residues. M-superfamily peptides appear to be ubiquitous in Conus venom. They are largely unexplained in indigenous biological function, and they represent an active area of research within the scientific community.
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Affiliation(s)
- Reed B. Jacob
- Department of Chemistry and Biochemistry, Boise State University, 1910 University Drive, Boise, ID 83725-1520 USA
| | - Owen M. McDougal
- Department of Chemistry and Biochemistry, Boise State University, 1910 University Drive, Boise, ID 83725-1520 USA
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32
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Khoo KK, Feng ZP, Smith BJ, Zhang MM, Yoshikami D, Olivera BM, Bulaj G, Norton RS. Structure of the analgesic mu-conotoxin KIIIA and effects on the structure and function of disulfide deletion. Biochemistry 2009; 48:1210-9. [PMID: 19170536 DOI: 10.1021/bi801998a] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mu-conotoxin mu-KIIIA, from Conus kinoshitai, blocks mammalian neuronal voltage-gated sodium channels (VGSCs) and is a potent analgesic following systemic administration in mice. We have determined its solution structure using NMR spectroscopy. Key residues identified previously as being important for activity against VGSCs (Lys7, Trp8, Arg10, Asp11, His12, and Arg14) all reside on an alpha-helix with the exception of Arg14. To further probe structure-activity relationships of this toxin against VGSC subtypes, we have characterized the analogue mu-KIIIA[C1A,C9A], in which the Cys residues involved in one of the three disulfides in mu-KIIIA were replaced with Ala. Its structure is quite similar to that of mu-KIIIA, indicating that the Cys1-Cys9 disulfide bond could be removed without any significant distortion of the alpha-helix bearing the key residues. Consistent with this, mu-KIIIA[C1A,C9A] retained activity against VGSCs, with its rank order of potency being essentially the same as that of mu-KIIIA, namely, Na(V)1.2 > Na(V)1.4 > Na(V)1.7 >or= Na(V)1.1 > Na(V)1.3 > Na(V)1.5. Kinetics of block were obtained for Na(V)1.2, Na(V)1.4, and Na(V)1.7, and in each case, both k(on) and k(off) values of mu-KIIIA[C1A,C9A] were larger than those of mu-KIIIA. Our results show that the key residues for VGSC binding lie mostly on an alpha-helix and that the first disulfide bond can be removed without significantly affecting the structure of this helix, although the modification accelerates the on and off rates of the peptide against all tested VGSC subtypes. These findings lay the groundwork for the design of minimized peptides and helical mimetics as novel analgesics.
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Affiliation(s)
- Keith K Khoo
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia
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Han TS, Zhang MM, Walewska A, Gruszczynski P, Robertson CR, Cheatham TE, Yoshikami D, Olivera BM, Bulaj G. Structurally minimized mu-conotoxin analogues as sodium channel blockers: implications for designing conopeptide-based therapeutics. ChemMedChem 2009; 4:406-14. [PMID: 19107760 DOI: 10.1002/cmdc.200800292] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Disulfide bridges that stabilize the native conformation of conotoxins pose a challenge in the synthesis of smaller conotoxin analogues. Herein we describe the synthesis of a minimized analogue of the analgesic mu-conotoxin KIIIA that blocks two sodium channel subtypes, the neuronal Na(V)1.2 and skeletal muscle Na(V)1.4. Three disulfide-deficient analogues of KIIIA were initially synthesized in which the native disulfide bridge formed between either C1-C9, C2-C15, or C4-C16 was removed. Deletion of the first bridge only slightly affected the peptide's bioactivity. To further minimize this analogue, the N-terminal residue was removed and two nonessential serine residues were replaced by a single 5-amino-3-oxapentanoic acid residue. The resulting "polytide" analogue retained the ability to block sodium channels and to produce analgesia. Until now, the peptidomimetic approach applied to conotoxins has progressed only modestly at best; thus, the disulfide-deficient analogues containing backbone spacers provide an alternative advance toward the development of conopeptide-based therapeutics.
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Affiliation(s)
- Tiffany S Han
- Department of Biology, University of Utah, 257 S 1400 E, Salt Lake City, UT 84112, USA
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Walewska A, Zhang MM, Skalicky JJ, Yoshikami D, Olivera BM, Bulaj G. Integrated oxidative folding of cysteine/selenocysteine containing peptides: improving chemical synthesis of conotoxins. Angew Chem Int Ed Engl 2009; 48:2221-4. [PMID: 19206132 DOI: 10.1002/anie.200806085] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Building bridges: The use of diselenide and selectively ((15)N/(13)C)-labeled disulfide bridges is combined to give improvements in oxidative folding and disulfide mapping. Conotoxin analogues, each with a pair of selenocysteines (Sec) and labeled cysteines (see scheme, red), exhibited significantly improved folding and the labeled cysteines allow correctly folded species to be rapidly identified by NMR spectroscopy.
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Walewska A, Zhang MM, Skalicky J, Yoshikami D, Olivera B, Bulaj G. Integrated Oxidative Folding of Cysteine/Selenocysteine Containing Peptides: Improving Chemical Synthesis of Conotoxins. Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200806085] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Biass D, Dutertre S, Gerbault A, Menou JL, Offord R, Favreau P, Stöcklin R. Comparative proteomic study of the venom of the piscivorous cone snail Conus consors. J Proteomics 2009; 72:210-8. [DOI: 10.1016/j.jprot.2009.01.019] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Accepted: 01/17/2009] [Indexed: 02/01/2023]
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