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Jin AH, Muttenthaler M, Dutertre S, Himaya SWA, Kaas Q, Craik DJ, Lewis RJ, Alewood PF. Conotoxins: Chemistry and Biology. Chem Rev 2019; 119:11510-11549. [PMID: 31633928 DOI: 10.1021/acs.chemrev.9b00207] [Citation(s) in RCA: 161] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The venom of the marine predatory cone snails (genus Conus) has evolved for prey capture and defense, providing the basis for survival and rapid diversification of the now estimated 750+ species. A typical Conus venom contains hundreds to thousands of bioactive peptides known as conotoxins. These mostly disulfide-rich and well-structured peptides act on a wide range of targets such as ion channels, G protein-coupled receptors, transporters, and enzymes. Conotoxins are of interest to neuroscientists as well as drug developers due to their exquisite potency and selectivity, not just against prey but also mammalian targets, thereby providing a rich source of molecular probes and therapeutic leads. The rise of integrated venomics has accelerated conotoxin discovery with now well over 10,000 conotoxin sequences published. However, their structural and pharmacological characterization lags considerably behind. In this review, we highlight the diversity of new conotoxins uncovered since 2014, their three-dimensional structures and folds, novel chemical approaches to their syntheses, and their value as pharmacological tools to unravel complex biology. Additionally, we discuss challenges and future directions for the field.
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Affiliation(s)
- Ai-Hua Jin
- Institute for Molecular Bioscience , The University of Queensland , Brisbane Queensland 4072 , Australia
| | - Markus Muttenthaler
- Institute for Molecular Bioscience , The University of Queensland , Brisbane Queensland 4072 , Australia.,Institute of Biological Chemistry, Faculty of Chemistry , University of Vienna , 1090 Vienna , Austria
| | - Sebastien Dutertre
- Département des Acides Amines, Peptides et Protéines, Unité Mixte de Recherche 5247, Université Montpellier 2-Centre Nationale de la Recherche Scientifique , Institut des Biomolécules Max Mousseron , Place Eugène Bataillon , 34095 Montpellier Cedex 5 , France
| | - S W A Himaya
- Institute for Molecular Bioscience , The University of Queensland , Brisbane Queensland 4072 , Australia
| | - Quentin Kaas
- Institute for Molecular Bioscience , The University of Queensland , Brisbane Queensland 4072 , Australia
| | - David J Craik
- Institute for Molecular Bioscience , The University of Queensland , Brisbane Queensland 4072 , Australia
| | - Richard J Lewis
- Institute for Molecular Bioscience , The University of Queensland , Brisbane Queensland 4072 , Australia
| | - Paul F Alewood
- Institute for Molecular Bioscience , The University of Queensland , Brisbane Queensland 4072 , Australia
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Yao G, Peng C, Zhu Y, Fan C, Jiang H, Chen J, Cao Y, Shi Q. High-Throughput Identification and Analysis of Novel Conotoxins from Three Vermivorous Cone Snails by Transcriptome Sequencing. Mar Drugs 2019; 17:md17030193. [PMID: 30917600 PMCID: PMC6471451 DOI: 10.3390/md17030193] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 03/19/2019] [Accepted: 03/25/2019] [Indexed: 12/13/2022] Open
Abstract
The venom of each Conus species consists of a diverse array of neurophysiologically active peptides, which are mostly unique to the examined species. In this study, we performed high-throughput transcriptome sequencing to extract and analyze putative conotoxin transcripts from the venom ducts of 3 vermivorous cone snails (C. caracteristicus, C. generalis, and C. quercinus), which are resident in offshore waters of the South China Sea. In total, 118, 61, and 48 putative conotoxins (across 22 superfamilies) were identified from the 3 Conus species, respectively; most of them are novel, and some possess new cysteine patterns. Interestingly, a series of 45 unassigned conotoxins presented with a new framework of C-C-C-C-C-C, and their mature regions were sufficiently distinct from any other known conotoxins, most likely representing a new superfamily. O- and M-superfamily conotoxins were the most abundant in transcript number and transcription level, suggesting their critical roles in the venom functions of these vermivorous cone snails. In addition, we identified numerous functional proteins with potential involvement in the biosynthesis, modification, and delivery process of conotoxins, which may shed light on the fundamental mechanisms for the generation of these important conotoxins within the venom duct of cone snails.
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Affiliation(s)
- Ge Yao
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Chao Peng
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China.
| | - Yabing Zhu
- BGI Genomics, BGI-Shenzhen, Shenzhen 518083, China.
| | - Chongxu Fan
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Hui Jiang
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Jisheng Chen
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Ying Cao
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Qiong Shi
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China.
- Laboratory of Aquatic Genomics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China.
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Fu Y, Li C, Dong S, Wu Y, Zhangsun D, Luo S. Discovery Methodology of Novel Conotoxins from Conus Species. Mar Drugs 2018; 16:md16110417. [PMID: 30380764 PMCID: PMC6266589 DOI: 10.3390/md16110417] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Revised: 10/21/2018] [Accepted: 10/25/2018] [Indexed: 12/17/2022] Open
Abstract
Cone snail venoms provide an ideal resource for neuropharmacological tools and drug candidates discovery, which have become a research hotspot in neuroscience and new drug development. More than 1,000,000 natural peptides are produced by cone snails, but less than 0.1% of the estimated conotoxins has been characterized to date. Hence, the discovery of novel conotoxins from the huge conotoxin resources with high-throughput and sensitive methods becomes a crucial key for the conotoxin-based drug development. In this review, we introduce the discovery methodology of new conotoxins from various Conus species. It focuses on obtaining full N- to C-terminal sequences, regardless of disulfide bond connectivity through crude venom purification, conotoxin precusor gene cloning, venom duct transcriptomics, venom proteomics and multi-omic methods. The protocols, advantages, disadvantages, and developments of different approaches during the last decade are summarized and the promising prospects are discussed as well.
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Affiliation(s)
- Ying Fu
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Hainan University, Haikou 570228, China.
| | - Cheng Li
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Hainan University, Haikou 570228, China.
| | - Shuai Dong
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Hainan University, Haikou 570228, China.
| | - Yong Wu
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Hainan University, Haikou 570228, China.
| | - Dongting Zhangsun
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Hainan University, Haikou 570228, China.
| | - Sulan Luo
- Key Laboratory for Marine Drugs of Haikou, Hainan University, Haikou 570228, China.
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Optimized deep-targeted proteotranscriptomic profiling reveals unexplored Conus toxin diversity and novel cysteine frameworks. Proc Natl Acad Sci U S A 2015; 112:E3782-91. [PMID: 26150494 DOI: 10.1073/pnas.1501334112] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cone snails are predatory marine gastropods characterized by a sophisticated venom apparatus responsible for the biosynthesis and delivery of complex mixtures of cysteine-rich toxin peptides. These conotoxins fold into small highly structured frameworks, allowing them to potently and selectively interact with heterologous ion channels and receptors. Approximately 2,000 toxins from an estimated number of >70,000 bioactive peptides have been identified in the genus Conus to date. Here, we describe a high-resolution interrogation of the transcriptomes (available at www.ddbj.nig.ac.jp) and proteomes of the diverse compartments of the Conus episcopatus venom apparatus. Using biochemical and bioinformatic tools, we found the highest number of conopeptides yet discovered in a single Conus specimen, with 3,305 novel precursor toxin sequences classified into 9 known superfamilies (A, I1, I2, M, O1, O2, S, T, Z), and identified 16 new superfamilies showing unique signal peptide signatures. We were also able to depict the largest population of venom peptides containing the pharmacologically active C-C-CC-C-C inhibitor cystine knot and CC-C-C motifs (168 and 44 toxins, respectively), as well as 208 new conotoxins displaying odd numbers of cysteine residues derived from known conotoxin motifs. Importantly, six novel cysteine-rich frameworks were revealed which may have novel pharmacology. Finally, analyses of codon usage bias and RNA-editing processes of the conotoxin transcripts demonstrate a specific conservation of the cysteine skeleton at the nucleic acid level and provide new insights about the origin of sequence hypervariablity in mature toxin regions.
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Conotoxin gene superfamilies. Mar Drugs 2014; 12:6058-101. [PMID: 25522317 PMCID: PMC4278219 DOI: 10.3390/md12126058] [Citation(s) in RCA: 130] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 11/29/2014] [Accepted: 12/04/2014] [Indexed: 12/16/2022] Open
Abstract
Conotoxins are the peptidic components of the venoms of marine cone snails (genus Conus). They are remarkably diverse in terms of structure and function. Unique potency and selectivity profiles for a range of neuronal targets have made several conotoxins valuable as research tools, drug leads and even therapeutics, and has resulted in a concerted and increasing drive to identify and characterise new conotoxins. Conotoxins are translated from mRNA as peptide precursors, and cDNA sequencing is now the primary method for identification of new conotoxin sequences. As a result, gene superfamily, a classification based on precursor signal peptide identity, has become the most convenient method of conotoxin classification. Here we review each of the described conotoxin gene superfamilies, with a focus on the structural and functional diversity present in each. This review is intended to serve as a practical guide to conotoxin superfamilies and to facilitate interpretation of the increasing number of conotoxin precursor sequences being identified by targeted-cDNA sequencing and more recently high-throughput transcriptome sequencing.
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Molecular evolution and diversity of Conus peptide toxins, as revealed by gene structure and intron sequence analyses. PLoS One 2013; 8:e82495. [PMID: 24349297 PMCID: PMC3862624 DOI: 10.1371/journal.pone.0082495] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2013] [Accepted: 10/25/2013] [Indexed: 11/19/2022] Open
Abstract
Cone snails, which are predatory marine gastropods, produce a cocktail of venoms used for predation, defense and competition. The major venom component, conotoxin, has received significant attention because it is useful in neuroscience research, drug development and molecular diversity studies. In this study, we report the genomic characterization of nine conotoxin gene superfamilies from 18 Conus species and investigate the relationships among conotoxin gene structure, molecular evolution and diversity. The I1, I2, M, O2, O3, P, S, and T superfamily precursors all contain three exons and two introns, while A superfamily members contain two exons and one intron. The introns are conserved within a certain gene superfamily, and also conserved across different Conus species, but divergent among different superfamilies. The intronic sequences contain many simple repeat sequences and regulatory elements that may influence conotoxin gene expression. Furthermore, due to the unique gene structure of conotoxins, the base substitution rates and the number of positively selected sites vary greatly among exons. Many more point mutations and trinucleotide indels were observed in the mature peptide exon than in the other exons. In addition, the first example of alternative splicing in conotoxin genes was found. These results suggest that the diversity of conotoxin genes has been shaped by point mutations and indels, as well as rare gene recombination or alternative splicing events, and that the unique gene structures could have made a contribution to the evolution of conotoxin genes.
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Bernáldez J, Román-González SA, Martínez O, Jiménez S, Vivas O, Arenas I, Corzo G, Arreguín R, García DE, Possani LD, Licea A. A Conus regularis conotoxin with a novel eight-cysteine framework inhibits CaV2.2 channels and displays an anti-nociceptive activity. Mar Drugs 2013; 11:1188-202. [PMID: 23567319 PMCID: PMC3705398 DOI: 10.3390/md11041188] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 03/05/2013] [Accepted: 03/18/2013] [Indexed: 12/22/2022] Open
Abstract
A novel peptide, RsXXIVA, was isolated from the venom duct of Conus regularis, a worm-hunting species collected in the Sea of Cortez, México. Its primary structure was determined by mass spectrometry and confirmed by automated Edman degradation. This conotoxin contains 40 amino acids and exhibits a novel arrangement of eight cysteine residues (C-C-C-C-CC-CC). Surprisingly, two loops of the novel peptide are highly identical to the amino acids sequence of ω-MVIIA. The total length and disulfide pairing of both peptides are quite different, although the two most important residues for the described function of ω-MVIIA (Lys2 and Tyr13) are also present in the peptide reported here. Electrophysiological analysis using superior cervical ganglion (SCG) neurons indicates that RsXXIVA inhibits CaV2.2 channel current in a dose-dependent manner with an EC50 of 2.8 μM, whose effect is partially reversed after washing. Furthermore, RsXXIVA was tested in hot-plate assays to measure the potential anti-nociceptive effect to an acute thermal stimulus, showing an analgesic effect in acute thermal pain at 30 and 45 min post-injection. Also, the toxin shows an anti-nociceptive effect in a formalin chronic pain test. However, the low affinity for CaV2.2 suggests that the primary target of the peptide could be different from that of ω-MVIIA.
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Affiliation(s)
- Johanna Bernáldez
- Molecular Immunology and Biotoxins Laboratory, Marine Biotechnology Department, Scientific Research and High Education Center from Ensenada (CICESE), Carretera Ensenada-Tijuana #3918, Zona Playitas, Ensenada 22860, Mexico; E-Mails: (J.B.); (O.M.); (S.J.)
| | - Sergio A. Román-González
- Chemistry Biomacromolecules Department, Chemistry Institute, National Autonomous University of Mexico, Av. Universidad 3000, Ciudad Universitaria, PO BOX 70-213, D.F. 04510, Mexico; E-Mails: (S.A.R.-G.); (R.A.)
| | - Oscar Martínez
- Molecular Immunology and Biotoxins Laboratory, Marine Biotechnology Department, Scientific Research and High Education Center from Ensenada (CICESE), Carretera Ensenada-Tijuana #3918, Zona Playitas, Ensenada 22860, Mexico; E-Mails: (J.B.); (O.M.); (S.J.)
| | - Samanta Jiménez
- Molecular Immunology and Biotoxins Laboratory, Marine Biotechnology Department, Scientific Research and High Education Center from Ensenada (CICESE), Carretera Ensenada-Tijuana #3918, Zona Playitas, Ensenada 22860, Mexico; E-Mails: (J.B.); (O.M.); (S.J.)
| | - Oscar Vivas
- Physiology Department, Medicine Faculty, National Autonomous University of Mexico, Av. Universidad 3000, Ciudad Universitaria, PO BOX 70-250, D.F. 04510, Mexico; E-Mails: (O.V.); (I.A.); (D.E.G.)
| | - Isabel Arenas
- Physiology Department, Medicine Faculty, National Autonomous University of Mexico, Av. Universidad 3000, Ciudad Universitaria, PO BOX 70-250, D.F. 04510, Mexico; E-Mails: (O.V.); (I.A.); (D.E.G.)
| | - Gerardo Corzo
- Department of Molecular Medicine and Bioprocesses, National Autonomous University of Mexico, Av. Universidad 2001, C.P. 510-3, Cuernavaca 61500, Mexico; E-Mails: (G.C.); (L.D.P.)
| | - Roberto Arreguín
- Chemistry Biomacromolecules Department, Chemistry Institute, National Autonomous University of Mexico, Av. Universidad 3000, Ciudad Universitaria, PO BOX 70-213, D.F. 04510, Mexico; E-Mails: (S.A.R.-G.); (R.A.)
| | - David E. García
- Physiology Department, Medicine Faculty, National Autonomous University of Mexico, Av. Universidad 3000, Ciudad Universitaria, PO BOX 70-250, D.F. 04510, Mexico; E-Mails: (O.V.); (I.A.); (D.E.G.)
| | - Lourival D. Possani
- Department of Molecular Medicine and Bioprocesses, National Autonomous University of Mexico, Av. Universidad 2001, C.P. 510-3, Cuernavaca 61500, Mexico; E-Mails: (G.C.); (L.D.P.)
| | - Alexei Licea
- Molecular Immunology and Biotoxins Laboratory, Marine Biotechnology Department, Scientific Research and High Education Center from Ensenada (CICESE), Carretera Ensenada-Tijuana #3918, Zona Playitas, Ensenada 22860, Mexico; E-Mails: (J.B.); (O.M.); (S.J.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel./Fax: +52-646-1750-500 (ext. 27201)
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A novel inhibitor of α9α10 nicotinic acetylcholine receptors from Conus vexillum delineates a new conotoxin superfamily. PLoS One 2013; 8:e54648. [PMID: 23382933 PMCID: PMC3559828 DOI: 10.1371/journal.pone.0054648] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 12/13/2012] [Indexed: 11/19/2022] Open
Abstract
Conotoxins (CTxs) selectively target a range of ion channels and receptors, making them widely used tools for probing nervous system function. Conotoxins have been previously grouped into superfamilies according to signal sequence and into families based on their cysteine framework and biological target. Here we describe the cloning and characterization of a new conotoxin, from Conus vexillum, named αB-conotoxin VxXXIVA. The peptide does not belong to any previously described conotoxin superfamily and its arrangement of Cys residues is unique among conopeptides. Moreover, in contrast to previously characterized conopeptide toxins, which are expressed initially as prepropeptide precursors with a signal sequence, a ‘‘pro’’ region, and the toxin-encoding region, the precursor sequence of αB-VxXXIVA lacks a ‘‘pro’’ region. The predicted 40-residue mature peptide, which contains four Cys, was synthesized in each of the three possible disulfide arrangements. Investigation of the mechanism of action of αB-VxXXIVA revealed that the peptide is a nicotinic acetylcholine receptor (nAChR) antagonist with greatest potency against the α9α10 subtype. 1H nuclear magnetic resonance (NMR) spectra indicated that all three αB-VxXXIVA isomers were poorly structured in aqueous solution. This was consistent with circular dichroism (CD) results which showed that the peptides were unstructured in buffer, but adopted partially helical conformations in aqueous trifluoroethanol (TFE) solution. The α9α10 nAChR is an important target for the development of analgesics and cancer chemotherapeutics, and αB-VxXXIVA represents a novel ligand with which to probe the structure and function of this protein.
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Liu Z, Li H, Liu N, Wu C, Jiang J, Yue J, Jing Y, Dai Q. Diversity and evolution of conotoxins in Conus virgo, Conus eburneus, Conus imperialis and Conus marmoreus from the South China Sea. Toxicon 2012; 60:982-9. [DOI: 10.1016/j.toxicon.2012.06.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 06/15/2012] [Accepted: 06/19/2012] [Indexed: 10/28/2022]
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Sun D, Ren Z, Zeng X, You Y, Pan W, Zhou M, Wang L, Xu A. Structure-function relationship of conotoxin lt14a, a potential analgesic with low cytotoxicity. Peptides 2011; 32:300-5. [PMID: 21126549 DOI: 10.1016/j.peptides.2010.11.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2009] [Revised: 11/13/2010] [Accepted: 11/15/2010] [Indexed: 11/20/2022]
Abstract
A novel conotoxin lt14a containing 13 amino acid residues with an amidated C-terminus derived from Conus litteratus, belongs to C-C-C-C cysteine pattern. As the smallest peptide of conotoxin framework 14, lt14a could inhibit nicotinic acetylcholine receptor and suppress pain. To elucidate structure-function relationship, we determine the solution structure by NMR and find that lt14a comprises a short duple β-strand region and β-turn motif. An analog [K7A]-lt14a of Ala substitution for Lys in position 7 is designed. Interestingly, [K7A]-lt14a exhibits higher activity than lt14a as long-lasting analgesic in the hotplate pain model in mice. Additionally, MTT assay reveals that the two peptides have low toxicity to human cells. The studies suggest that positively charged residue may not be involved in the blocking mechanism. However, due to the Ala substitution, hydrophobic residues' patch expansion strengthens the binding ability. A hypothesis is given that in conotoxin lt14a, hydrophobic residues rather than charged residues play a key role during target binding.
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Affiliation(s)
- Dandan Sun
- Department of Biochemistry, Sun Yat-sen University, Guangzhou, 510275, People's Republic of China
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Liu Z, Yu Z, Liu N, Zhao C, Hu J, Dai Q. cDNA cloning of conotoxins with framework XII from several Conus species. Acta Biochim Biophys Sin (Shanghai) 2010; 42:656-61. [PMID: 20732855 DOI: 10.1093/abbs/gmq066] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In our efforts for cloning novel I(2)-superfamily conotoxins using the signal peptide sequence, we identified a novel conotoxin Lt12.4 from Conus litteratus. This gene has a framework XII (-C-C-C-C-CC-C-C-), which is distinct from the cysteine pattern I(2)-superfamily conotoxin (-C-C-CC-CC-C-C-). Subsequently, we found the signal peptide sequence of Lt12.4 by 5'-RACE. Using this new sequence, we identified another five novel conotoxins with this cysteine pattern from four Conus species (Conus eburneus, Conus imperialis, Conus marmoreus, and C. litteratus). These novel conotoxins have the same cysteine pattern as the reported Gla-TxX and Gla-MII, and may contain Gla residues. Furthermore, they have the highly conserved signal peptide and hypervariable mature peptide sequences, and widely exist in Conus species. Therefore, it could be defined as a new superfamily of E-conotoxins.
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Affiliation(s)
- Zhuguo Liu
- Beijing Institute of Biotechnology, China
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Kaas Q, Westermann JC, Craik DJ. Conopeptide characterization and classifications: an analysis using ConoServer. Toxicon 2010; 55:1491-509. [PMID: 20211197 DOI: 10.1016/j.toxicon.2010.03.002] [Citation(s) in RCA: 160] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Revised: 02/25/2010] [Accepted: 03/01/2010] [Indexed: 10/19/2022]
Abstract
Cone snails are carnivorous marine gastropods that have evolved potent venoms to capture their prey. These venoms comprise a rich and diverse cocktail of peptide toxins, or conopeptides, whose high diversity has arisen from an efficient hypermutation mechanism, combined with a high frequency of post-translational modifications. Conopeptides bind with high specificity to distinct membrane receptors, ion channels, and transporters of the central and muscular nervous system. As well as serving their natural function in prey capture, conopeptides have been utilized as versatile tools in neuroscience and have proven valuable as drug leads that target the nervous system in humans. This paper examines current knowledge on conopeptide sequences based on an analysis of gene and peptide sequences in ConoServer (http://www.conoserver.org), a specialized database of conopeptide sequences and three-dimensional structures. We describe updates to the content and organization of ConoServer and discuss correlations between gene superfamilies, cysteine frameworks, pharmacological families targeted by conopeptides, and the phylogeny, habitat, and diet of cone snails. The study identifies gaps in current knowledge of conopeptides and points to potential directions for future research.
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Affiliation(s)
- Quentin Kaas
- The University of Queensland, Institute for Molecular Bioscience, Division of Chemistry and Structural Biology, Brisbane, 4072 QLD, Australia
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Abstract
Venomous marine cone snails harbour a variety of small disulfide-rich peptides called conotoxins, which target a broad range of ion channels, membrane receptors, and transporters. More than 700 species of Conus are thought to exist, each expressing a wide array of different peptides. Within this large repertoire of toxins, individual conotoxins are able to discriminate between different subtypes and isoforms of ion channels, making them valuable pharmacological probes or leads for drug design. This review gives a brief background to the discovery of conotoxins and describes their sequences, biological activities, and applications in drug design.
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Affiliation(s)
- Reena Halai
- The University of Queensland, Institute for Molecular Bioscience, Brisbane, Queensland 4072, Australia
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Yuan DD, Liu L, Shao XX, Peng C, Chi CW, Guo ZY. New conotoxins define the novel I3-superfamily. Peptides 2009; 30:861-5. [PMID: 19428762 DOI: 10.1016/j.peptides.2009.01.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Revised: 01/20/2009] [Accepted: 01/21/2009] [Indexed: 11/29/2022]
Abstract
We purified two novel conotoxins, designated as ca11a and ca11b, from the venom of Conus caracteristicus. Based on the amino acid sequence of mature ca11a, we cloned its full-length cDNA. Based on the signal peptide of ca11a, several ca11a-like conotoxins were cloned from C. caracteristicus and C. pulicarius. These novel conotoxins have an I-superfamily cysteine pattern but with a novel signal peptide sequence, suggesting they belong to a new branch of I-superfamily, designated as I(3)-superfamily. Additionally, two O-superfamily conotoxins were also cloned based on the signal peptide of ca11a, suggesting a possible evolutionary relationship between O- and I-superfamilies.
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Affiliation(s)
- Duo-Duo Yuan
- Institute of Protein Research, College of Life Sciences and Technology, Tongji University, Shanghai, PR China
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