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Chen J, Liu X, Yu S, Liu J, Chen R, Zhang Y, Jiang L, Dai Q. A novel ω-conotoxin Bu8 inhibiting N-type voltage-gated calcium channels displays potent analgesic activity. Acta Pharm Sin B 2021; 11:2685-2693. [PMID: 34589389 PMCID: PMC8463271 DOI: 10.1016/j.apsb.2021.03.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/13/2021] [Accepted: 03/01/2021] [Indexed: 01/11/2023] Open
Abstract
ω-Conotoxins inhibit N-type voltage-gated calcium (CaV2.2) channels and exhibit efficacy in attenuating neuropathic pain but have a low therapeutic index. Here, we synthesized and characterized a novel ω-conotoxin, Bu8 from Conus bullatus, which consists of 25 amino acid residues and three disulfide bridges. Bu8 selectively and potently inhibits depolarization-activated Ba2+ currents mediated by rat CaV2.2 expressed in HEK293T cells (IC50 = 89 nmol/L). Bu8 is two-fold more potent than ω-conotoxin MVIIA, a ω-conotoxin currently used for the treatment of severe chronic pain. It also displays potent analgesic activity in animal pain models of hot plate and acetic acid writhing but has fewer side effects on mouse motor function and lower toxicity in goldfish. Its lower side effects may be attributed to its faster binding rate and higher recovery ratios. The NMR structure demonstrates that Bu8 contains a small irregular triple β-strand. The structure-activity relationships of Bu8 Ala mutants and Bu8/MVIIA hybrid mutants demonstrate that the binding mode of CaV2.2 with the amino acid residues in loop 1 and loop 2 of Bu8 is different from that of MVIIA. This study characterizes a novel, more potent ω-conotoxin and provides new insights for designing CaV2.2 antagonists.
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Key Words
- Analgesic activity
- Bu8
- DIEA, diisopropylethylamine
- ESI-MS, electrospray ionization-mass spectroscopy
- Fmoc, N-(9-fluorenyl)methyloxy-carbonyl
- HBTU, 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate
- HOBt, 1-hydroxybenzotriazole
- IC50, half-maximal inhibitory concentration
- N-type calcium ion channel
- RP-HPLC, reversed phase high-performance liquid chromatography
- Structure–activity relationship
- TFA, trifluoroacetic acid
- ω-conotoxin
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Affiliation(s)
- Jinqin Chen
- Beijing Institute of Biotechnology, Beijing 100071, China
| | - Xinhong Liu
- Key Laboratory of Magnetic Resonance in Biological System, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shuo Yu
- Beijing Institute of Biotechnology, Beijing 100071, China
| | - Jia Liu
- Beijing Institute of Biotechnology, Beijing 100071, China
| | - Rongfang Chen
- Beijing Institute of Biotechnology, Beijing 100071, China
| | - Yunxiao Zhang
- College of Life Science, Hunan Normal University, Changsha 410081, China
| | - Ling Jiang
- Key Laboratory of Magnetic Resonance in Biological System, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China
- Corresponding authors. Tel: +86 10 66948897.
| | - Qiuyun Dai
- Beijing Institute of Biotechnology, Beijing 100071, China
- Corresponding authors. Tel: +86 10 66948897.
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Dong M, Wang F, Yan Z, Yu S, Wei J, Wu Q, Liu Z, Tang Y, Ding J, Dai Q. Structure-Activity Analysis of N-Type Calcium Channel Inhibitor SO-3. Biochemistry 2018; 57:6349-6355. [PMID: 30281282 DOI: 10.1021/acs.biochem.8b00803] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
As an ω-conopeptide originally discovered from Conus striatus, SO-3 contains 25 amino acid residues and three disulfide bridges. Our previous study has shown that this peptide possesses potent analgesic activity in rodent pain models (mouse and rat), and it specifically inhibits an N-type calcium ion channel (Cav2.2). In the study presented here, we investigated the key amino acid residues for their inhibitory activity against Cav2.2 expressed in HEK 293 cells and analgesic activity in mice. To improve the inhibitory activity of SO-3, we also evaluated the effects of some amino acid residues derived from the corresponding residues of ω-peptide MVIIA, CVID, or GVIA. Our data reveal that Lys6, Ile11, and Asn14 are the important functional amino acid residues for SO-3. The replacement of some amino acid residues of SO-3 in loop 1 with the corresponding residues of CVID and GVIA improved the inhibitory activity of SO-3. The binding mode of Cav2.2 with SO-3 amino acids in loop 1 and loop 2 may be somewhat different from that of MVIIA. This study expanded our knowledge of the structure-activity relationship of ω-peptides and provided a new strategy for improving the potency of Cav2.2 inhibitors.
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Affiliation(s)
- Minxing Dong
- Beijing Institute of Biotechnology , Beijing 100071 , China
| | - Fei Wang
- Beijing Institute of Biotechnology , Beijing 100071 , China
| | - Zhenzhen Yan
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Shuo Yu
- Beijing Institute of Biotechnology , Beijing 100071 , China
| | - Juanjuan Wei
- Beijing Institute of Biotechnology , Beijing 100071 , China
| | - Qiaoling Wu
- Beijing Institute of Biotechnology , Beijing 100071 , China
| | - Zhuguo Liu
- Beijing Institute of Biotechnology , Beijing 100071 , China
| | - Yifei Tang
- Beijing Institute of Biotechnology , Beijing 100071 , China
| | - Jiuping Ding
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Qiuyun Dai
- Beijing Institute of Biotechnology , Beijing 100071 , China
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Vink S, Alewood PF. Targeting voltage-gated calcium channels: developments in peptide and small-molecule inhibitors for the treatment of neuropathic pain. Br J Pharmacol 2013; 167:970-89. [PMID: 22725651 DOI: 10.1111/j.1476-5381.2012.02082.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Chronic pain affects approximately 20% of people worldwide and places a large economic and social burden on society. Despite the availability of a range of analgesics, this condition is inadequately treated, with complete alleviation of symptoms rarely occurring. In the past 30 years, the voltage-gated calcium channels (VGCCs) have been recognized as potential targets for analgesic development. Although the majority of the research has been focused on Ca(v) 2.2 in particular, other VGCC subtypes such as Ca(v) 3.2 have recently come to the forefront of analgesic research. Venom peptides from marine cone snails have been proven to be a valuable tool in neuroscience, playing a major role in the identification and characterization of VGCC subtypes and producing the first conotoxin-based drug on the market, the ω-conotoxin, ziconotide. This peptide potently and selectively inhibits Ca(v) 2.2, resulting in analgesia in chronic pain states. However, this drug is only available via intrathecal administration, and adverse effects and a narrow therapeutic window have limited its use in the clinic. Other Ca(v) 2.2 inhibitors are currently in development and offer the promise of an improved route of administration and safety profile. This review assesses the potential of targeting VGCCs for analgesic development, with a main focus on conotoxins that block Ca(v) 2.2 and the developments made to transform them into therapeutics.
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Affiliation(s)
- S Vink
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
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Bingham JP, Andrews EA, Kiyabu SM, Cabalteja CC. Drugs from slugs. Part II--conopeptide bioengineering. Chem Biol Interact 2012; 200:92-113. [PMID: 23063744 DOI: 10.1016/j.cbi.2012.09.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2012] [Revised: 08/27/2012] [Accepted: 09/17/2012] [Indexed: 11/27/2022]
Abstract
The biological transformation of toxins as research probes, or as pharmaceutical drug leads, is an onerous and drawn out process. Issues regarding changes to pharmacological specificity, desired potency, and bioavailability are compounded naturally by their inherent toxicity. These often scuttle their progress as they move up the narrowing drug development pipeline. Yet one class of peptide toxins, from the genus Conus, has in many ways spearheaded the expansion of new peptide bioengineering techniques to aid peptide toxin pharmaceutical development. What has now emerged is the sequential bioengineering of new research probes and drug leads that owe their lineage to these highly potent and isoform specific peptides. Here we discuss the progressive bioengineering steps that many conopeptides have transitioned through, and specifically illustrate some of the biochemical approaches that have been established to maximize their biological research potential and pharmaceutical worth.
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Affiliation(s)
- Jon-Paul Bingham
- Department of Molecular Biosciences and Bioengineering, University of Hawaii, Honolulu, HI 96822, USA.
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Hopping G, Lewis RJ, Alewood PF. Rapid Access to ω-Conotoxin Chimeras using Native Chemical Ligation. Aust J Chem 2009. [DOI: 10.1071/ch09216] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Grafting different regions of related peptides together to form a single protein chimera is a valuable tool in rapidly elucidating regions of activity or selectivity in peptides and proteins. To conveniently evaluate the contributions of the N- and C-terminal segments of ω-conotoxins CVID and MVIIC to activity, we employed native chemical ligation in CVID-MVIIC chimera design. Assembly of these peptide segments via the ligation method improved overall yield and coupling efficiency, with no difficult sequences encountered in contrast to the traditional full-length chain assembly of CVID. Radio-ligand binding assays revealed regions of importance for receptor recognition.
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Abstract
Ziconotide is a powerful analgesic drug that has a unique mechanism of action involving potent and selective block of N-type calcium channels, which control neurotransmission at many synapses. The analgesic efficacy of ziconotide likely results from its ability to interrupt pain signaling at the level of the spinal cord. Ziconotide is a peptidic drug and has been approved for the treatment of severe chronic pain in patients only when administered by the intrathecal route. Importantly, prolonged administration of ziconotide does not lead to the development of addiction or tolerance. The current review discusses the various studies that have addressed the in vitro biochemical and electrophysiological actions of ziconotide as well as the numerous pre-clinical studies that were conducted to elucidate its antinociceptive mechanism of action in animals. In addition, this review considers the pivotal Phase 3 (and other) clinical trials that were conducted in support of ziconotide's approval for the treatment of severe chronic pain and tries to offer some insights regarding the future discovery and development of newer analgesic drugs that would act by a similar mechanism to ziconotide but which might offer improved safety, tolerability and ease of use.
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Ibañez-Tallon I, Wen H, Miwa JM, Xing J, Tekinay AB, Ono F, Brehm P, Heintz N. Tethering Naturally Occurring Peptide Toxins for Cell-Autonomous Modulation of Ion Channels and Receptors In Vivo. Neuron 2004; 43:305-11. [PMID: 15294139 DOI: 10.1016/j.neuron.2004.07.015] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2004] [Revised: 07/06/2004] [Accepted: 07/07/2004] [Indexed: 11/18/2022]
Abstract
The physiologies of cells depend on electrochemical signals carried by ion channels and receptors. Venomous animals produce an enormous variety of peptide toxins with high affinity for specific ion channels and receptors. The mammalian prototoxin lynx1 shares with alpha-bungarotoxin the ability to bind and modulate nicotinic receptors (nAChRs); however, lynx1 is tethered to the membrane via a GPI anchor. We show here that several classes of neurotoxins, including bungarotoxins and cobratoxins, retain their selective antagonistic properties when tethered to the membrane. Targeted elimination of nAChR function in zebrafish can be achieved with tethered alpha-bungarotoxin, silencing synaptic transmission without perturbing synapse formation. These studies harness the pharmacological properties of peptide toxins for use in genetic experiments. When combined with specific methods of cell and temporal expression, the extension of this approach to hundreds of naturally occurring peptide toxins opens a new landscape for cell-autonomous regulation of cellular physiology in vivo.
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Affiliation(s)
- Inés Ibañez-Tallon
- Howard Hughes Medical Institute, Laboratory of Molecular Biology, The Rockefeller University, New York, NY 10021, USA
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Bernard C, Corzo G, Adachi-Akahane S, Foures G, Kanemaru K, Furukawa Y, Nakajima T, Darbon H. Solution structure of ADO1, a toxin extracted from the saliva of the assassin bug, Agriosphodrus dohrni. Proteins 2004; 54:195-205. [PMID: 14696181 DOI: 10.1002/prot.10513] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
ADO1 is a toxin purified from the saliva of the assassin bug, Agriosphodrus dohrni. Because of its similarity in sequence to Ptu1 from another assassin bug, we did not assess its pharmacologic target. Here, we demonstrate by electrophysiologic means that ADO1 targets the P/Q-type voltage-sensitive calcium channel. We also determine the solution structure of ADO1 using two-dimensional NMR techniques, followed by distance geometry and molecular dynamics. The structure of ADO1 belongs to the inhibitory cystine knot (ICK) structural family (i.e., a compact disulfide-bonded core from which four loops emerge). ADO1 contains a two-stranded, antiparallel beta-sheet structure. We compare the structure of ADO1 with other voltage-sensitive calcium-channel blockers, analyze the topologic juxtaposition of key functional residues, and conclude that the recognition of voltage-sensitive calcium channels by toxins belonging to the ICK structural family requires residues located on two distinct areas of the molecular surface of the toxins.
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Affiliation(s)
- Cédric Bernard
- Architecture et Fonction des Macromolécules Biologiques, UMR 6098, CNRS and Universités d'Aix-Marseille I and II, Marseille, France
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El Ayadi A, Afailal I, Errami M. Effects of voltage-sensitive calcium channel blockers on extracellular dopamine levels in rat striatum. Metab Brain Dis 2001; 16:121-31. [PMID: 11769325 DOI: 10.1023/a:1012549225235] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Various subtypes of voltage-sensitive calcium channels (VSCCs) support the release of dopamine (DA) in the central nervous system. Using in vivo microdialysis, we investigate the influence of these subtypes of calcium channels on dopaminergic terminals in the rat striatum. L-type (nifedipine-sensitive), N-type (omega-conotoxin GVIA-sensitive), or N- and P/Q-type (omega-conotoxin MVIIC-sensitive) Ca2+ channels were blocked using selective antagonists injected locally, and K+-evoked DA release was measured in freely moving animals. K+ (100 mM) induced a massive increase of basal DA extracellular levels (930%) and was without significant effect on extracellular levels of DA metabolites DOPAC and HVA, and on the serotonin metabolite 5HIAA. Omega-conotoxin GVIA (1 microM) and omega-conotoxin MVIIC (1 microM) significantly reduced the K+-evoked DA release by 55 and 62%, respectively. The simultaneous application of the two conotoxins at the same concentration reduced K+-evoked DA release by 66%. Nifedipine (10 microM) had no significant effect on K-evoked DA release, while neomycin, a nonspecific VSCC blocker, produced a highly significant decrease when applied at 250 and 500 microM (56 and 75%, respectively). The compounds. however, had no effect on basal DA release and on the levels of extracellular DOPAC, HVA, and 5HIAA. These results suggest that under high and persistent conditions of membrane depolarization (15 min, 10 mM K+), striatal DA release is mainly mediated by N-type VSCCs.
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Affiliation(s)
- A El Ayadi
- Abdelmalek Essâadi University, Laboratory of Neuropharmacology, Faculty of Sciences, Tétouan, Morocco
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Abstract
This review focuses on the advances in the development of N-type calcium channel blockers as analgesic agents over the last 2 years. Firstly, it highlights the clinical progress with SNX-111 (Ziconotide; Elan Pharmaceuticals, Smithfield, RI) and then secondly, it outlines the various approaches being taken by researchers to design orally active, selective, small molecule modulators without the perceived disadvantages associated with SNX-111.
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Affiliation(s)
- B Cox
- Glaxo Wellcome Research and Development, Department of Medicinal Chemistry 1, Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, United Kingdom.
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Minami K, Raymond C, Martin-Moutot N, Ohtake A, Van Renterghem C, Takahashi M, Seagar MJ, Mori Y, Sato K. Role of Thr(11) in the binding of omega-conotoxin MVIIC to N-type Ca2+ channels. FEBS Lett 2001; 491:127-30. [PMID: 11226434 DOI: 10.1016/s0014-5793(01)02183-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
As replacement of Thr(11) of omega-conotoxin MVIIC with Ala significantly reduced the affinity for both N- and P/Q-type calcium channels, we examined the effect of substitution at this position with other residues. Binding assays using rat cerebellar P2 membranes showed that the affinity is in the order of Leu>Val, aminobutyric acid, Thr>Asn&z.Gt;Ser, Ala, Asp, Phe, Tyr for N-type channels and Thr>Leu, Val, aminobutyric acid, Asn, Ser>Ala&z.Gt;Asp, Phe, Tyr for P/Q-type channels, suggesting that aliphatic amino acids with longer side chains are favorable for block of N-type channels. The effects of substitution were examined electrophysiologically in BHK cells expressing N-type Ca2+ channels. Inhibition of Ba2+ current by the analogs did not completely correlate with binding affinity, although binding to BHK cells was comparable to rat cerebellar membranes.
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Affiliation(s)
- K Minami
- Mitsubishi Kasei Institute of Life Sciences, 11 Minamiooya, Machida, Tokyo 194-8511, Japan
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Balaji RA, Sasaki T, Gopalakrishnakone P, Sato K, Kini RM, Bay BH. Purification, structure determination and synthesis of covalitoxin-II, a short insect-specific neurotoxic peptide from the venom of the Coremiocnemis validus (Singapore tarantula). FEBS Lett 2000; 474:208-12. [PMID: 10838086 DOI: 10.1016/s0014-5793(00)01593-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Spider venoms contain toxins that specifically immobilize and kill insects. We report the purification and characterization of a new insect-specific toxin named covalitoxin-II (Cvtx-II; mass, 3406. 24+/-0.64), from Coremiocnemis validus (Singapore tarantula) venom. The complete 31 amino acid sequence of Cvtx-II has been determined and it shows less than 40% identity with spider toxins. However, Cvtx-II has conserved cystine motif analogous to other spider and omega-conotoxins. Cvtx-II was chemically synthesized and identified with the native Cvtx-II. Synthetic Cvtx-II induced insect-specific non-lethal excitatory activity when injected into crickets, but not in cockroaches and mice.
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Affiliation(s)
- R A Balaji
- Venom and Toxin Research Programme, Department of Anatomy, Faculty of Medicine, National University of Singapore, Singapore
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