1
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Farhat S, Modica MV, Puillandre N. Whole Genome Duplication and Gene Evolution in the Hyperdiverse Venomous Gastropods. Mol Biol Evol 2023; 40:msad171. [PMID: 37494290 PMCID: PMC10401626 DOI: 10.1093/molbev/msad171] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 06/20/2023] [Accepted: 07/17/2023] [Indexed: 07/28/2023] Open
Abstract
The diversity of venomous organisms and the toxins they produce have been increasingly investigated, but taxonomic bias remains important. Neogastropods, a group of marine predators representing almost 22% of the known gastropod diversity, evolved a wide range of feeding strategies, including the production of toxins to subdue their preys. However, whether the diversity of these compounds is at the origin of the hyperdiversification of the group and how genome evolution may correlate with both the compounds and species diversities remain understudied. Among the available gastropods genomes, only eight, with uneven quality assemblies, belong to neogastropods. Here, we generated chromosome-level assemblies of two species belonging to the Tonnoidea and Muricoidea superfamilies (Monoplex corrugatus and Stramonita haemastoma). The two obtained high-quality genomes had 3 and 2.2 Gb, respectively, and 92-89% of the total assembly conformed 35 pseudochromosomes in each species. Through the analysis of syntenic blocks, Hox gene cluster duplication, and synonymous substitutions distribution pattern, we inferred the occurrence of a whole genome duplication event in both genomes. As these species are known to release venom, toxins were annotated in both genomes, but few of them were found in homologous chromosomes. A comparison of the expression of ohnolog genes (using transcriptomes from osphradium and salivary glands in S. haemastoma), where both copies were differentially expressed, showed that most of them had similar expression profiles. The high quality of these genomes makes them valuable reference in their respective taxa, facilitating the identification of genome-level processes at the origin of their evolutionary success.
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Affiliation(s)
- Sarah Farhat
- Institut Systématique Evolution Biodiversité (ISYEB), Muséum national d'Histoire naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, Paris, France
| | - Maria Vittoria Modica
- Department of Biology and Evolution of Marine Organisms (BEOM), Stazione Zoologica Anton Dohrn, Roma, Italy
| | - Nicolas Puillandre
- Institut Systématique Evolution Biodiversité (ISYEB), Muséum national d'Histoire naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, Paris, France
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2
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Jian X, Wu Y, Mei Z, Zhu X, Zhangsun D, Luo S. Synthesis of the Most Potent Isomer of μ-Conotoxin KIIIA Using Different Strategies. Molecules 2023; 28:molecules28083377. [PMID: 37110612 PMCID: PMC10143212 DOI: 10.3390/molecules28083377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 03/30/2023] [Accepted: 04/08/2023] [Indexed: 04/29/2023] Open
Abstract
In the chemical synthesis of conotoxins with multiple disulfide bonds, the oxidative folding process can result in diverse disulfide bond connectivities, which presents a challenge for determining the natural disulfide bond connectivities and leads to significant structural differences in the synthesized toxins. Here, we focus on KIIIA, a μ-conotoxin that has high potency in inhibiting Nav1.2 and Nav1.4. The non-natural connectivity pattern (C1-C9, C2-C15, C4-C16) of KIIIA exhibits the highest activity. In this study, we report an optimized Fmoc solid-phase synthesis of KIIIA using various strategies. Our results indicate that free random oxidation is the simplest method for peptides containing triple disulfide bonds, resulting in high yields and a simplified process. Alternatively, the semi-selective strategy utilizing Trt/Acm groups can also produce the ideal isomer, albeit with a lower yield. Furthermore, we performed distributed oxidation using three different protecting groups, optimizing their positions and cleavage order. Our results showed that prioritizing the cleavage of the Mob group over Acm may result in disulfide bond scrambling and the formation of new isomers. We also tested the activity of synthesized isomers on Nav1.4. These findings provide valuable guidance for the synthesis of multi-disulfide-bonded peptides in future studies.
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Affiliation(s)
- Xunxun Jian
- School of Medicine, Guangxi University, Nanning 530004, China
| | - Yong Wu
- School of Medicine, Guangxi University, Nanning 530004, China
| | - Zaoli Mei
- School of Medicine, Guangxi University, Nanning 530004, China
| | - Xiaopeng Zhu
- School of Medicine, Guangxi University, Nanning 530004, China
| | - Dongting Zhangsun
- School of Medicine, Guangxi University, Nanning 530004, China
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou 570228, China
| | - Sulan Luo
- School of Medicine, Guangxi University, Nanning 530004, China
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou 570228, China
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3
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Espiritu MJ, Taylor JK, Sugai CK, Thapa P, Loening NM, Gusman E, Baoanan ZG, Baumann MH, Bingham JP. Characterization of the Native Disulfide Isomers of the Novel χ-Conotoxin PnID: Implications for Further Increasing Conotoxin Diversity. Mar Drugs 2023; 21:61. [PMID: 36827103 PMCID: PMC9964023 DOI: 10.3390/md21020061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 01/11/2023] [Accepted: 01/17/2023] [Indexed: 01/21/2023] Open
Abstract
χ-Conotoxins are known for their ability to selectively inhibit norepinephrine transporters, an ability that makes them potential leads for treating various neurological disorders, including neuropathic pain. PnID, a peptide isolated from the venom of Conus pennaceus, shares high sequence homology with previously characterized χ-conotoxins. Whereas previously reported χ-conotoxins seem to only have a single native disulfide bonding pattern, PnID has three native isomers due to the formation of different disulfide bond patterns during its maturation in the venom duct. In this study, the disulfide connectivity and three-dimensional structure of these disulfide isomers were explored using regioselective synthesis, chromatographic coelution, and solution-state nuclear magnetic resonance spectroscopy. Of the native isomers, only the isomer with a ribbon disulfide configuration showed pharmacological activity similar to other χ-conotoxins. This isomer inhibited the rat norepinephrine transporter (IC50 = 10 ± 2 µM) and has the most structural similarity to previously characterized χ-conotoxins. In contrast, the globular isoform of PnID showed more than ten times less activity against this transporter and the beaded isoform did not display any measurable biological activity. This study is the first report of the pharmacological and structural characterization of an χ-conotoxin from a species other than Conus marmoreus and is the first report of the existence of natively-formed conotoxin isomers.
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Affiliation(s)
- Michael J. Espiritu
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai’i, Honolulu, HI 96822, USA
- School of Pharmacy, Pacific University, 222 SE 8th Ave, Ste. 451, Hillsboro, OR 97123, USA
| | - Jonathan K. Taylor
- School of Pharmacy, Pacific University, 222 SE 8th Ave, Ste. 451, Hillsboro, OR 97123, USA
| | - Christopher K. Sugai
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai’i, Honolulu, HI 96822, USA
| | - Parashar Thapa
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai’i, Honolulu, HI 96822, USA
| | - Nikolaus M. Loening
- Department of Chemistry, Lewis & Clark College, 615 S Palatine Hill Road, Portland, OR 97219, USA
| | - Emma Gusman
- School of Pharmacy, Pacific University, 222 SE 8th Ave, Ste. 451, Hillsboro, OR 97123, USA
| | - Zenaida G. Baoanan
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai’i, Honolulu, HI 96822, USA
- Department of Biology, College of Science, University of the Philippines Baguio, Baguio City 2600, Philippines
| | - Michael H. Baumann
- Designer Drug Research Unit, Intramural Research Program, National Institute on Drug Abuse (NIDA), National Institutes of Health (NIH), 333 Cassell Drive Suite 4400, Baltimore, MD 21224, USA
| | - Jon-Paul Bingham
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai’i, Honolulu, HI 96822, USA
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4
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Sanches K, Wai DCC, Norton RS. Conformational dynamics in peptide toxins: Implications for receptor interactions and molecular design. Toxicon 2021; 201:127-140. [PMID: 34454969 DOI: 10.1016/j.toxicon.2021.08.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 08/19/2021] [Accepted: 08/23/2021] [Indexed: 10/20/2022]
Abstract
Peptide toxins are potent and often exquisitely selective probes of the structure and function of ion channels and receptors, and are therefore of significant interest to the pharmaceutical and biotech industries as both pharmacological tools and therapeutic leads. The three-dimensional structures of peptide toxins are essential as a basis for understanding their structure-activity relationships and their binding to target receptors, as well as in guiding the design of analogues with modified potency and/or selectivity for key targets. NMR spectroscopy has played a key role in elucidating the structures of peptide toxins and probing their structure-function relationships. In this article, we highlight the additional important contribution of NMR to characterising the dynamics of peptide toxins. We also compare the information available from NMR measurements with that afforded by molecular dynamics simulations. We describe several examples of the importance of dynamics measurements over a range of timescales for understanding the structure-function relationships of peptide toxins and their receptor engagement. Peptide toxins that inhibit the voltage-gated potassium channel KV1.3 with pM affinities display different degrees of conformational flexibility, even though they contain multiple disulfide bonds, and this flexibility can affect the relative orientation of residues that have been shown to be critical for channel binding. Information on the dynamic properties of peptide toxins is important in the design of analogues or mimetics where receptor-bound structures are not available.
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Affiliation(s)
- Karoline Sanches
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia; ARC Centre for Fragment-Based Design, Monash University, Parkville, Victoria, 3052, Australia
| | - Dorothy C C Wai
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia
| | - Raymond S Norton
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia; ARC Centre for Fragment-Based Design, Monash University, Parkville, Victoria, 3052, Australia.
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5
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Rügen N, Jenkins TP, Wielsch N, Vogel H, Hempel BF, Süssmuth RD, Ainsworth S, Cabezas-Cruz A, Vilcinskas A, Tonk M. Hexapod Assassins' Potion: Venom Composition and Bioactivity from the Eurasian Assassin Bug Rhynocoris iracundus. Biomedicines 2021; 9:biomedicines9070819. [PMID: 34356883 PMCID: PMC8301361 DOI: 10.3390/biomedicines9070819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 07/07/2021] [Accepted: 07/08/2021] [Indexed: 11/16/2022] Open
Abstract
Assassin bug venoms are potent and exert diverse biological functions, making them potential biomedical goldmines. Besides feeding functions on arthropods, assassin bugs also use their venom for defense purposes causing localized and systemic reactions in vertebrates. However, assassin bug venoms remain poorly characterized. We collected the venom from the assassin bug Rhynocoris iracundus and investigated its composition and bioactivity in vitro and in vivo. It caused lysis of murine neuroblastoma, hepatoma cells, and healthy murine myoblasts. We demonstrated, for the first time, that assassin bug venom induces neurolysis and suggest that it counteracts paralysis locally via the destruction of neural networks, contributing to tissue digestion. Furthermore, the venom caused paralysis and melanization of Galleria mellonella larvae and pupae, whilst also possessing specific antibacterial activity against Escherichia coli, but not Listeria grayi and Pseudomonas aeruginosa. A combinatorial proteo-transcriptomic approach was performed to identify potential toxins responsible for the observed effects. We identified neurotoxic Ptu1, an inhibitory cystin knot (ICK) toxin homologous to ω-conotoxins from cone snails, cytolytic redulysins homologous to trialysins from hematophagous kissing bugs, and pore-forming hemolysins. Additionally, chitinases and kininogens were found and may be responsible for insecticidal and cytolytic activities. We demonstrate the multifunctionality and complexity of assassin bug venom, which renders its molecular components interesting for potential biomedical applications.
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Affiliation(s)
- Nicolai Rügen
- Department of Bioresources, Fraunhofer Institute for Molecular Biology and Applied Ecology, Ohlebergsweg 12, 35392 Giessen, Germany; (N.R.); (A.V.)
| | - Timothy P. Jenkins
- Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800 Kongens Lyngby, Denmark;
| | - Natalie Wielsch
- Research Group Mass Spectrometry/Proteomics, Max Planck Institute for Chemical Ecology, Hans-Knoell-Strasse 8, 07745 Jena, Germany;
| | - Heiko Vogel
- Department of Entomology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745 Jena, Germany;
| | - Benjamin-Florian Hempel
- Department of Chemistry, Technische Universität Berlin, Strasse des 17. Juni 124, 10623 Berlin, Germany; (B.-F.H.); (R.D.S.)
- BIH Center for Regenerative Therapies BCRT, Charité—Universitätsmedizin Berlin, 13353 Berlin, Germany
| | - Roderich D. Süssmuth
- Department of Chemistry, Technische Universität Berlin, Strasse des 17. Juni 124, 10623 Berlin, Germany; (B.-F.H.); (R.D.S.)
| | - Stuart Ainsworth
- Centre for Snakebite Research and Interventions, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK;
| | - Alejandro Cabezas-Cruz
- UMR BIPAR, Laboratoire de Santé Animale, Anses, INRAE, Ecole Nationale Vétérinaire d’Alfort, F-94700 Maisons-Alfort, France;
| | - Andreas Vilcinskas
- Department of Bioresources, Fraunhofer Institute for Molecular Biology and Applied Ecology, Ohlebergsweg 12, 35392 Giessen, Germany; (N.R.); (A.V.)
- Institute for Insect Biotechnology, Justus Liebig University of Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany
- LOEWE Centre for Translational Biodiversity Genomics (LOEWE-TBG), Senckenberganlage 25, 60325 Frankfurt, Germany
| | - Miray Tonk
- Institute for Insect Biotechnology, Justus Liebig University of Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany
- LOEWE Centre for Translational Biodiversity Genomics (LOEWE-TBG), Senckenberganlage 25, 60325 Frankfurt, Germany
- Correspondence:
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6
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Hwang HJ, Patnaik BB, Chung JM, Sang MK, Park JE, Kang SW, Park SY, Jo YH, Park HS, Baliarsingh S, Han YS, Lee JS, Lee YS. De novo transcriptome sequencing of triton shell Charonia lampas sauliae: Identification of genes related to neurotoxins and discovery of genetic markers. Mar Genomics 2021; 59:100862. [PMID: 33827771 DOI: 10.1016/j.margen.2021.100862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 02/05/2021] [Accepted: 02/24/2021] [Indexed: 11/20/2022]
Abstract
Charonia lampas sauliae (triton snails, triton shells or tritons; Mollusca, Caenogastropoda, Littorinimorpha, Ranellidae) is a marine species with a wide distribution. In Korea, this species is listed as vulnerable and is regionally protected as an endangered species. Here, we report the first comprehensive transcriptome dataset of C. lampas sauliae obtained using the Illumina HiSeq 2500 platform. In total, 97.68% of raw read sequences were processed as clean reads. Of the 577,478 contigs obtained, 146,026 sequences were predicted to contain coding regions. About 89.34% of all annotated unigene sequences showed homologous matches to protein sequences in PANM DB (Protostome database). Further, about one-third of the unigene sequences were annotated using the UniGene, Swiss-Prot, Clusters of Orthologous Groups (COG) and Gene Ontology (GO) databases. In total, 190 enzymes were predicted under key metabolic pathways under stood through Kyoto Encyclopedia of Genes and Genomes (KEGG) database annotation. Repetitive elements such as long terminal repeats (LTRs), short interspersed nuclear elements (SINEs), long interspersed nuclear elements (LINEs), and DNA elements were enriched in the unigene sequences. Among the identified transcripts were the channel proteins, some of which were blocked by tetrodotoxin, which is thought to be synthesized by symbiotic bacteria inhabiting the shells. In addition, conotoxin superfamily peptides, such as B-conotoxin, conotoxin superfamily T and alpha-conotoxin, were identified, which may have relevance to biomedical and evolutionary research. A transcriptome-wide search for polymorphic loci identified 21,568 simple sequence repeats (SSRs) in the unigene sequences. Most SSRs were dinucleotides, among which AC/GT was the dominant SSR type. The molecular and genetic resources revealed in this study could be utilized for investigations on the fitness of the species in the marine environment and sustainability in a changing habitat.
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7
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Bao N, Lecaer JP, Nghia ND, Vinh PTK. Isolation and structural identification of a new T1-conotoxin with unique disulfide connectivities derived from Conus bandanus. J Venom Anim Toxins Incl Trop Dis 2020; 26:e20190095. [PMID: 32425993 PMCID: PMC7216822 DOI: 10.1590/1678-9199-jvatitd-2019-0095] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 04/15/2020] [Indexed: 08/30/2023] Open
Abstract
Background: Conopeptides are neuropharmacological peptides derived from the venomous
salivary glands of cone snails. Among 29 superfamilies based on conserved
signal sequences, T-superfamily conotoxins, which belong to the smallest
group, include four different frameworks that contain four cysteines
denominated I, V, X and XVI. In this work, the primary structure and the
cysteine connectivity of novel conotoxin of Conus bandanus
were determined by tandem mass spectrometry using collision-induced
dissociation. Methods: The venom glands of C. bandanus snails were dissected,
pooled, and extracted with 0.1% trifluoroacetic acid in three steps and
lyophilized. The venom was fractionated and purified in an HPLC system with
an analytical reversed-phase C18 column. The primary peptide
structure was analyzed by MALDI TOF MS/MS using collision-induced
dissociation and confirmed by Edman's degradation. The peptide’s cysteine
connectivity was determined by rapid partial reduction-alkylation
technique. Results: The novel conotoxin,
NGC1C2(I/L)VREC3C4, was
firstly derived from de novo sequencing by MS/MS. The
presence of isoleucine residues in this conotoxin was confirmed by the Edman
degradation method. The conotoxin, denominated Bn5a, belongs to the
T1-subfamily of conotoxins. However, the disulfide bonds
(C1-C4/C2-C3) of Bn5a were
not the same as found in other T1-subfamily conopeptides but shared common
connectivities with T2-subfamily conotoxins. The T1-conotoxin of C.
bandanus proved the complexity of the disulfide bond pattern of
conopeptides. The homological analysis revealed that the novel conotoxin
could serve as a valuable probe compound for the human-nervous-system
norepinephrine transporter. Conclusion: We identified the first T1-conotoxin, denominated Bn5a, isolated from
C. bandanus venom. However, Bn5a conotoxin exhibited
unique C1-C4/C2-C3 disulfide
connectivity, unlike other T1-conotoxins
(C1-C3/C2-C4). The
structural and homological analyses herein have evidenced novel conotoxin
Bn5a that may require further investigation.
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Affiliation(s)
- Nguyen Bao
- Faculty of Food Technology, Nha Trang University, 02 Nguyen Dinh Chieu, Nha Trang, Khanh Hoa, Vietnam
| | - Jean-Pière Lecaer
- Institut de Chimie des Substances Naturelles, Centre de Recherche de Gif, FRC3115, UPR 2301, F-91198 Gif-sur-Yvette, France
| | - Ngo Dang Nghia
- Institute of Biotechnology and Environment, Nha Trang University, 02 Nguyen Dinh Chieu, Nha Trang, Khanh Hoa, Vietnam
| | - Phan Thi Khanh Vinh
- Faculty of Food Technology, Nha Trang University, 02 Nguyen Dinh Chieu, Nha Trang, Khanh Hoa, Vietnam
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Mohan MK, Abraham N, R P R, Jayaseelan BF, Ragnarsson L, Lewis RJ, Sarma SP. Structure and allosteric activity of a single-disulfide conopeptide from Conus zonatus at human α3β4 and α7 nicotinic acetylcholine receptors. J Biol Chem 2020; 295:7096-7112. [PMID: 32234761 DOI: 10.1074/jbc.ra119.012098] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 03/26/2020] [Indexed: 11/06/2022] Open
Abstract
Conopeptides are neurotoxic peptides in the venom of marine cone snails and have broad therapeutic potential for managing pain and other conditions. Here, we identified the single-disulfide peptides Czon1107 and Cca1669 from the venoms of Conus zonatus and Conus caracteristicus, respectively. We observed that Czon1107 strongly inhibits the human α3β4 (IC50 15.7 ± 3.0 μm) and α7 (IC50 77.1 ± 0.05 μm) nicotinic acetylcholine receptor (nAChR) subtypes, but the activity of Cca1669 remains to be identified. Czon1107 acted at a site distinct from the orthosteric receptor site. Solution NMR experiments revealed that Czon1107 exists in equilibrium between conformational states that are the result of a key Ser4-Pro5 cis-trans isomerization. Moreover, we found that the X-Pro amide bonds in the inter-cysteine loop are rigidly constrained to cis conformations. Structure-activity experiments of Czon1107 and its variants at positions P5 and P7 revealed that the conformation around the X-Pro bonds (cis-trans) plays an important role in receptor subtype selectivity. The cis conformation at the Cys6-Pro7 peptide bond was essential for α3β4 nAChR subtype allosteric selectivity. In summary, we have identified a unique single-disulfide conopeptide with a noncompetitive, potentially allosteric inhibitory mechanism at the nAChRs. The small size and rigidity of the Czon1107 peptide could provide a scaffold for rational drug design strategies for allosteric nAChR modulation. This new paradigm in the "conotoxinomic" structure-function space provides an impetus to screen venom from other Conus species for similar, short bioactive peptides that allosterically modulate ligand-gated receptor function.
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Affiliation(s)
- Madhan Kumar Mohan
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Nikita Abraham
- Institute for Molecular Bioscience, Queensland Bioscience Precinct, The University of Queensland, 306 Carmody Rd., St. Lucia Queensland 4072, Australia
| | - Rajesh R P
- Sathyabama Institute of Science and Technology, Jeppiaar Nagar, Rajiv Gandhi Salai, Chennai 600119, Tamil Nadu, India
| | | | - Lotten Ragnarsson
- Institute for Molecular Bioscience, Queensland Bioscience Precinct, The University of Queensland, 306 Carmody Rd., St. Lucia Queensland 4072, Australia
| | - Richard J Lewis
- Institute for Molecular Bioscience, Queensland Bioscience Precinct, The University of Queensland, 306 Carmody Rd., St. Lucia Queensland 4072, Australia
| | - Siddhartha P Sarma
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India
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9
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Safavi-Hemami H, Brogan SE, Olivera BM. Pain therapeutics from cone snail venoms: From Ziconotide to novel non-opioid pathways. J Proteomics 2018; 190:12-20. [PMID: 29777871 DOI: 10.1016/j.jprot.2018.05.009] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 05/15/2018] [Indexed: 01/04/2023]
Abstract
There have been numerous attempts to develop non-opioid drugs for severe pain, but the vast majority of these efforts have failed. A notable exception is Ziconotide (Prialt®), approved by the FDA in 2004. In this review, we summarize the present status of Ziconotide as a therapeutic drug and introduce a wider framework: the potential of venom peptides from cone snails as a resource providing a continuous pipeline for the discovery of non-opioid pain therapeutics. An auxiliary theme that we hope to develop is that these venoms, already a validated starting point for non-opioid drug leads, should also provide an opportunity for identifying novel molecular targets for future pain drugs. This review comprises several sections: the first focuses on Ziconotide as a therapeutic (including a historical retrospective and a clinical perspective); followed by sections on other promising Conus venom peptides that are either in clinical or pre-clinical development. We conclude with a discussion on why the outlook for discovery appears exceptionally promising. The combination of new technologies in diverse fields, including the development of novel high-content assays and revolutionary advancements in transcriptomics and proteomics, puts us at the cusp of providing a continuous pipeline of non-opioid drug innovations for pain. SIGNIFICANCE: The current opioid epidemic is the deadliest drug crisis in American history. Thus, this review on the discovery of non-opioid pain therapeutics and pathways from cone snail venoms is significant and timely.
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Affiliation(s)
| | - Shane E Brogan
- Anesthesiology, University of Utah, Salt Lake City, UT, United States; Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, United States
| | - Baldomero M Olivera
- Departments of Biology, University of Utah, Salt Lake City, UT, United States
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10
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Yu S, Du T, Liu Z, Wu Q, Feng G, Dong M, Zhou X, Jiang L, Dai Q. Im10A, a short conopeptide isolated from Conus imperialis and possesses two highly concentrated disulfide bridges and analgesic activity. Peptides 2016; 81:15-20. [PMID: 27131596 DOI: 10.1016/j.peptides.2016.04.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 04/02/2016] [Accepted: 04/26/2016] [Indexed: 12/27/2022]
Abstract
In the present study, we isolated, synthesized and NMR structurally characterized a novel conopeptide Im10A consisting of 11 amino acids (NTICCEGCMCY-NH2) from Conus imperialis. Unlike other conopeptides with four cysteine residues, Im10A had only two residues in loop 1 and one residue in loop 2 (CC-loop1-C-loop2-C), which formed a stable disulfide connectivity "I-IV, II- III" (framework X) with a type I β-turn. Interestingly, Im10A exhibited 50.7% analgesic activity on rat partial sciatic nerve ligation (PNL) at 2h after Im10A administration. However, 10μM Im10A exhibited no apparent effect on neuronal nicotinic acetylcholine receptor, and it did not target DRG voltage-dependent sodium, potassium and calcium ion channels and opioid receptor. To our knowledge, Im10A had the most concentrated disulfide bridges among conopeptides with four cysteine residues. This finding provided a new motif for the future development of biomimetic compounds.
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Affiliation(s)
- Shuo Yu
- Beijing Institute of Biotechnology, Beijing 10071, PR China
| | - Tianpeng Du
- Key Laboratory of Magnetic Resonance in Biological Systems, National Center for Magnetic Resonance in Wuhan, State Key laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Science, Wuhan 430071, PR China
| | - Zhuguo Liu
- Beijing Institute of Biotechnology, Beijing 10071, PR China
| | - Qiaoling Wu
- Beijing Institute of Biotechnology, Beijing 10071, PR China
| | - Guixue Feng
- Beijing Institute of Biotechnology, Beijing 10071, PR China
| | - Mingxin Dong
- Beijing Institute of Biotechnology, Beijing 10071, PR China
| | - Xiaowei Zhou
- Beijing Institute of Biotechnology, Beijing 10071, PR China
| | - Ling Jiang
- Key Laboratory of Magnetic Resonance in Biological Systems, National Center for Magnetic Resonance in Wuhan, State Key laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Science, Wuhan 430071, PR China.
| | - Qiuyun Dai
- Beijing Institute of Biotechnology, Beijing 10071, PR China.
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11
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Krejmer M, Skrzecz I, Wasag B, Szewczyk B, Rabalski L. The genome of Dasychira pudibunda nucleopolyhedrovirus (DapuNPV) reveals novel genetic connection between baculoviruses infecting moths of the Lymantriidae family. BMC Genomics 2015; 16:759. [PMID: 26449402 PMCID: PMC4599791 DOI: 10.1186/s12864-015-1963-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 09/29/2015] [Indexed: 11/10/2022] Open
Abstract
Background DapuNPV (Dasychira pudibunda nucleopolyhedrovirus), presented in this report, belongs to Alphabaculovirus group Ib. Its full, newly sequenced genome shows close relationship to baculovirus OpMNPV isolated from douglas-fir tussock moth Orgyia pseudotsugata. Baculovirus DapuNPV is a natural limiter of pale tussock moth Dasychira pudibunda L. (syn. Calliteara pudibunda L.)(Lepidoptera, Lymantriidae), which can occur in a form of an outbreak on many species of deciduous trees and may cause significant economic losses in the forests. Methods Late instars dead larvae of pale tussock moth were mechanically homogenized and polyhedra were purified during series of ultracentrifugation. Viral DNA was extarcted and sequenced using Miseq Illumina platform. 294,902 paired reads were used for de novo assembling. Genome annotation, multiple allingment to others baculoviruses and phylogegentic analises were perform with the use of multiple bioinformatic tools like: Glimmer3, HMMER web server, Geneious 7 and MEGA6. Results The genome of DapuNPV is 136,761 bp long with AT pairs content 45.6 %. The predicted number of encoded putative open reading frames (ORFs) is 161 and six of them demonstrate low or no homology to ORFs previously found in baculoviruses. DapuNPV genome shows very high similarity to OpMNPV in a nucleotide sequence (91.1 % of identity) and gene content (150 homologous ORFs), though some major differences (e.g. lack of he65 in OpMNPV) have also been noted. Conclusions Similarly to other members of the Baculoviridae family, DapuNPV baculovirus possesses highly conserved core genes. Among them, there is a second copy of occluded derived virus envelope 27 protein (odv-e27), which was previously found only in a member of Alphabaculovirus group II – LyxyMNPV (Lymantria xylina MNPV). Surprisingly enough, DapuNPV and LyxyMNPV genomes share also another feature. Phylogenetic analysis of chitin binding family protein (cbpl) indicates significant similarity of those two baculoviruses from distinct evolutionary groups which infect the same hosts from Lymantriidae. The ubiquitin like family gene (ubil), which has not been described until now, is another characteristic component of DapuNPV genome. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1963-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Martyna Krejmer
- Department of Recombinant Vaccines, Intercollegiate Faculty of Biotechnology University of Gdansk and Medical University of Gdansk, 80-822, Gdansk, Kladki Str. 24, Poland.
| | - Iwona Skrzecz
- Forest Research Institute, Department of Forest Protection, 05-090, Raszyn, Braci Lesnej Str. 3, Sekocin Stary, Poland.
| | - Bartosz Wasag
- Department of Biology and Genetics, Medical University of Gdansk, 80-211, Gdansk, Debinki Str. 1, Poland.
| | - Boguslaw Szewczyk
- Department of Recombinant Vaccines, Intercollegiate Faculty of Biotechnology University of Gdansk and Medical University of Gdansk, 80-822, Gdansk, Kladki Str. 24, Poland.
| | - Lukasz Rabalski
- Department of Recombinant Vaccines, Intercollegiate Faculty of Biotechnology University of Gdansk and Medical University of Gdansk, 80-822, Gdansk, Kladki Str. 24, Poland.
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12
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Prashanth JR, Brust A, Jin AH, Alewood PF, Dutertre S, Lewis RJ. Cone snail venomics: from novel biology to novel therapeutics. Future Med Chem 2014; 6:1659-75. [PMID: 25406006 DOI: 10.4155/fmc.14.99] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Peptide neurotoxins from cone snails called conotoxins are renowned for their therapeutic potential to treat pain and several neurodegenerative diseases. Inefficient assay-guided discovery methods have been replaced by high-throughput bioassays integrated with advanced MS and next-generation sequencing, ushering in the era of 'venomics'. In this review, we focus on the impact of venomics on the understanding of cone snail biology as well as the application of venomics to accelerate the discovery of new conotoxins. We also discuss the continued importance of medicinal chemistry approaches to optimize conotoxins for clinical use, with a descriptive case study of MrIA featured.
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13
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Lavergne V, Harliwong I, Jones A, Miller D, Taft RJ, Alewood PF. 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] [What about the content of this article? (0)] [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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14
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Franklin JB, Rajesh RP. A sleep-inducing peptide from the venom of the Indian cone snail Conus araneosus. Toxicon 2015; 103:39-47. [PMID: 26100663 DOI: 10.1016/j.toxicon.2015.06.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 06/15/2015] [Accepted: 06/17/2015] [Indexed: 12/23/2022]
Abstract
The marine snail Conus araneosus has unusual significance due to its confined distribution to coastal regions of southeast India and Sri Lanka. Due to its relative scarceness, this species has been poorly studied. In this work, we characterized the venom of C. araneosus to identify new venom peptides. We identified 14 novel compounds. We determined amino acid sequences from chemically-modified and unmodified crude venom using liquid chromatography-electrospray ionization mass spectrometry and matrix assisted laser desorption ionization time-of-flight mass spectrometry. Ten sequences showed six Cys residues arranged in a pattern that is most commonly associated with the M-superfamily of conotoxins. Four other sequences had four Cys residues in a pattern that is most commonly associated with the T-superfamily of conotoxins. The post-translationally modified residue (pyroglutamate) was determined at the N-terminus of two sequences, ar3h and ar3i respectively. In addition, two sequences, ar3g and ar3h were C-terminally amidated. At a dose of 2 nmol, peptide ar3j elicited sleep when injected intraperitoneally into mice. To our knowledge, this is the first report of a peptide from a molluscivorous cone snail with sleep-inducing effects in mice. The novel peptides characterized herein extend the repertoire of unique peptides derived from cone snails and may add value to the therapeutic promise of conotoxins.
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15
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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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16
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Wang S, Du T, Liu Z, Wang S, Wu Y, Ding J, Jiang L, Dai Q. Characterization of a T-superfamily conotoxin TxVC from Conus textile that selectively targets neuronal nAChR subtypes. Biochem Biophys Res Commun 2014; 454:151-6. [DOI: 10.1016/j.bbrc.2014.10.055] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 10/12/2014] [Indexed: 11/19/2022]
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17
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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: 224] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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18
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Wu Y, Wu X, Yu J, Zhu X, Zhangsun D, Luo S. Influence of disulfide connectivity on structure and bioactivity of α-conotoxin TxIA. Molecules 2014; 19:966-79. [PMID: 24434670 DOI: 10.3390/molecules19010966] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 01/07/2014] [Accepted: 01/09/2014] [Indexed: 11/17/2022] Open
Abstract
Cone snails express a sophisticated arsenal of small bioactive peptides known as conopeptides or conotoxins (CTxs). Through evolutionary selection, these peptides have gained the ability to interact with a range of ion channels and receptors, such as nicotinic acetylcholine receptors (nAChRs). Here, we used reversed-phase high performance liquid chromatography (RP-HPLC) and electrospray ionization-mass spectrometry (ESI-MS) to explore the venom peptide diversity of Conus textile, a species of cone snail native to Hainan, China. One fraction of C. textile crude venom potently blocked α3β2 nAChRs. Subsequent purification, synthesis, and tandem mass spectrometric analysis demonstrated that the most active compound in this fraction was identical to α-CTx TxIA, an antagonist of α3β2 nAChRs. Then three disulfide isoforms of α-CTx TxIA were synthesized and their activities were investigated systematically for the first time. As we observed, disulfide isomerisation was particularly important for α-CTx TxIA potency. Although both globular and ribbon isomers showed similar retention times in RP-HPLC, globular TxIA potently inhibited α3β2 nAChRs with an IC50 of 5.4 nM, while ribbon TxIA had an IC50 of 430 nM. In contrast, beads isomer had little activity towards α3β2 nAChRs. Two-step oxidation synthesis produced the highest yield of α-CTx TxIA native globular isomer, while a one-step production process based on random oxidation folding was not suitable. In summary, this study demonstrated the relationship between conotoxin activity and disulfide connectivity on α-CTx TxIA.
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Nguyen B, Molgó J, Lamthanh H, Benoit E, Khuc TA, Ngo DN, Nguyen NT, Millares P, Le Caer J. High accuracy mass spectrometry comparison of Conus bandanus and Conus marmoreus venoms from the South Central Coast of Vietnam. Toxicon 2013; 75:148-59. [DOI: 10.1016/j.toxicon.2013.06.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 05/10/2013] [Accepted: 06/11/2013] [Indexed: 11/20/2022]
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20
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Peigneur S, Yamaguchi Y, Goto H, Srinivasan KN, Gopalakrishnakone P, Tytgat J, Sato K. Synthesis and characterization of amino acid deletion analogs of κ-hefutoxin 1, a scorpion toxin on potassium channels. Toxicon 2013; 71:25-30. [DOI: 10.1016/j.toxicon.2013.05.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 05/15/2013] [Indexed: 10/26/2022]
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21
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Ng ASA, Kini RM. Structural determinants in protein folding: a single conserved hydrophobic residue determines folding of EGF domains. ACS Chem Biol 2013; 8:161-9. [PMID: 23094971 DOI: 10.1021/cb300445a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The epidermal growth factor (EGF) domain is evolutionarily conserved despite hypervariability in amino acid sequences. They fold into a three-looped conformation with a disulfide pairing of C(1)-C(3), C(2)-C(4) ,and C(5)-C(6). To elucidate the structural determinants that dictate the EGF fold, we selected the fourth and fifth EGF domains of thrombomodulin (TM) as models; the former domain folds into the canonical conformation, while the latter domain folds with alternate disulfide pairing of C(1)-C(2), C(3)-C(4), and C(5)-C(6). Since their third disulfide (C(5)-C(6)) is conserved, we examined the folding tendencies of synthetic peptides corresponding to truncated domain four (t-TMEGF4) and five (t-TMEGF5), encompassing the segment C(1) to C(4). These peptides fold into their respective disulfide isoforms indicating that they contain all the required structural determinants. On the basis of the folding tendencies of these peptides in the absence and presence of 6 M Gn·HCl or 0.5 M NaCl, we determined that hydrophobic interactions are needed for the canonical EGF fold but not for the noncanonical fold. Sequence alignment of extant EGF domains and examination of their three-dimensional structures allowed us to identify a highly conserved hydrophobic residue in intercysteine loop 3 as the key contributor, which nucleates the hydrophobic core and acts as the lynch pin. When this hydrophobic residue (Tyr25) was substituted with a more hydrophilic Thr, the hydrophobic interactions were disrupted, and t-TMEGF4-Y25T folds similar to t-TMEGF5. Taken together, our results for the first time demonstrate that a single conserved hydrophobic residue acts as the key determinant in the folding of EGF domains.
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Affiliation(s)
- A. S. Angie Ng
- Department of Biological Sciences,
Faculty of Science, National University of Singapore, Singapore 117543, Singapore
| | - R. Manjunatha Kini
- Department of Biological Sciences,
Faculty of Science, National University of Singapore, Singapore 117543, Singapore
- Department of Biochemistry,
Medical College of Virginia, Virginia Commonwealth University, Richmond, Virginia 23298-0614, United States
- School of Pharmacy and Medical
Sciences, University of South Australia, Adelaide, South Australia 5000, Australia
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22
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Gyanda R, Banerjee J, Chang YP, Phillips AM, Toll L, Armishaw CJ. Oxidative folding and preparation of α-conotoxins for use in high-throughput structure-activity relationship studies. J Pept Sci 2012. [PMID: 23193084 DOI: 10.1002/psc.2467] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
α-Conotoxins are peptide neurotoxins that selectively inhibit various subtypes of nicotinic acetylcholine receptors. They are important research tools for studying numerous pharmacological disorders, with profound potential for developing drug leads for treating pain, tobacco addiction, and other conditions. They are characterized by the presence of two disulfide bonds connected in a globular arrangement, which stabilizes a bioactive helical conformation. Despite extensive structure-activity relationship studies that have produced α-conotoxin analogs with increased potency and selectivity towards specific nicotinic acetylcholine receptor subtypes, the efficient production of diversity-oriented α-conotoxin combinatorial libraries has been limited by inefficient folding and purification procedures. We have investigated the optimized conditions for the reliable folding of α-conotoxins using simplified oxidation procedures for use in the accelerated production of synthetic combinatorial libraries of α-conotoxins. To this end, the effect of co-solvent, redox reagents, pH, and temperature on the proportion of disulfide bond isomers was determined for α-conotoxins exhibiting commonly known Cys loop spacing frameworks. In addition, we have developed high-throughput 'semi-purification' methods for the quick and efficient parallel preparation of α-conotoxin libraries for use in accelerated structure-activity relationship studies. Our simplified procedures represent an effective strategy for the preparation of large arrays of correctly folded α-conotoxin analogs and permit the rapid identification of active hits directly from high-throughput pharmacological screening assays.
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Affiliation(s)
- Reena Gyanda
- Torrey Pines Institute for Molecular Studies, Port St Lucie, Florida 34987, USA
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23
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Dutertre S, Jin AH, Kaas Q, Jones A, Alewood PF, Lewis RJ. Deep venomics reveals the mechanism for expanded peptide diversity in cone snail venom. Mol Cell Proteomics 2012; 12:312-29. [PMID: 23152539 DOI: 10.1074/mcp.m112.021469] [Citation(s) in RCA: 160] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Cone snails produce highly complex venom comprising mostly small biologically active peptides known as conotoxins or conopeptides. Early estimates that suggested 50-200 venom peptides are produced per species have been recently increased at least 10-fold using advanced mass spectrometry. To uncover the mechanism(s) responsible for generating this impressive diversity, we used an integrated approach combining second-generation transcriptome sequencing with high sensitivity proteomics. From the venom gland transcriptome of Conus marmoreus, a total of 105 conopeptide precursor sequences from 13 gene superfamilies were identified. Over 60% of these precursors belonged to the three gene superfamilies O1, T, and M, consistent with their high levels of expression, which suggests these conotoxins play an important role in prey capture and/or defense. Seven gene superfamilies not previously identified in C. marmoreus, including five novel superfamilies, were also discovered. To confirm the expression of toxins identified at the transcript level, the injected venom of C. marmoreus was comprehensively analyzed by mass spectrometry, revealing 2710 and 3172 peptides using MALDI and ESI-MS, respectively, and 6254 peptides using an ESI-MS TripleTOF 5600 instrument. All conopeptides derived from transcriptomic sequences could be matched to masses obtained on the TripleTOF within 100 ppm accuracy, with 66 (63%) providing MS/MS coverage that unambiguously confirmed these matches. Comprehensive integration of transcriptomic and proteomic data revealed for the first time that the vast majority of the conopeptide diversity arises from a more limited set of genes through a process of variable peptide processing, which generates conopeptides with alternative cleavage sites, heterogeneous post-translational modifications, and highly variable N- and C-terminal truncations. Variable peptide processing is expected to contribute to the evolution of venoms, and explains how a limited set of ∼ 100 gene transcripts can generate thousands of conopeptides in a single species of cone snail.
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Affiliation(s)
- Sébastien Dutertre
- The Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
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24
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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25
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26
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Gupta K, Kumar M, Balaram P. Disulfide Bond Assignments by Mass Spectrometry of Native Natural Peptides: Cysteine Pairing in Disulfide Bonded Conotoxins. Anal Chem 2010; 82:8313-9. [DOI: 10.1021/ac101867e] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Kallol Gupta
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore-560012, India, and National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore-560065, India
| | - Mukesh Kumar
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore-560012, India, and National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore-560065, India
| | - Padmanabhan Balaram
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore-560012, India, and National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore-560065, India
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Brust A, Palant E, Croker DE, Colless B, Drinkwater R, Patterson B, Schroeder CI, Wilson D, Nielsen CK, Smith MT, Alewood D, Alewood PF, Lewis RJ. χ-Conopeptide Pharmacophore Development: Toward a Novel Class of Norepinephrine Transporter Inhibitor (Xen2174) for Pain. J Med Chem 2009; 52:6991-7002. [DOI: 10.1021/jm9003413] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Andreas Brust
- Xenome Ltd., 120 Meiers Road, Indooroopilly, Queensland, Australia 4068
| | - Elka Palant
- Xenome Ltd., 120 Meiers Road, Indooroopilly, Queensland, Australia 4068
| | - Daniel E. Croker
- Xenome Ltd., 120 Meiers Road, Indooroopilly, Queensland, Australia 4068
| | - Barbara Colless
- Xenome Ltd., 120 Meiers Road, Indooroopilly, Queensland, Australia 4068
| | - Roger Drinkwater
- Xenome Ltd., 120 Meiers Road, Indooroopilly, Queensland, Australia 4068
| | - Brad Patterson
- Xenome Ltd., 120 Meiers Road, Indooroopilly, Queensland, Australia 4068
| | | | - David Wilson
- Xenome Ltd., 120 Meiers Road, Indooroopilly, Queensland, Australia 4068
| | | | | | - Dianne Alewood
- Xenome Ltd., 120 Meiers Road, Indooroopilly, Queensland, Australia 4068
| | | | - Richard J. Lewis
- Xenome Ltd., 120 Meiers Road, Indooroopilly, Queensland, Australia 4068
- Institute of Molecular Biosciences
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Kasheverov IE, Zhmak MN, Fish A, Rucktooa P, Khruschov AY, Osipov AV, Ziganshin RH, D'hoedt D, Bertrand D, Sixma TK, Smit AB, Tsetlin VI. Interaction of alpha-conotoxin ImII and its analogs with nicotinic receptors and acetylcholine-binding proteins: additional binding sites on Torpedo receptor. J Neurochem 2009; 111:934-44. [PMID: 19712060 DOI: 10.1111/j.1471-4159.2009.06359.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
alpha-Conotoxins interact with nicotinic acetylcholine receptors (nAChRs) and acetylcholine-binding proteins (AChBPs) at the sites for agonists/competitive antagonists. alpha-Conotoxins blocking muscle-type or alpha7 nAChRs compete with alpha-bungarotoxin. However, alpha-conotoxin ImII, a close homolog of the alpha7 nAChR-targeting alpha-conotoxin ImI, blocked alpha7 and muscle nAChRs without displacing alpha-bungarotoxin (Ellison et al. 2003, 2004), suggesting binding at a different site. We synthesized alpha-conotoxin ImII, its ribbon isomer (ImIIiso), 'mutant' ImII(W10Y) and found similar potencies in blocking human alpha7 and muscle nAChRs in Xenopus oocytes. Both isomers displaced [(125)I]-alpha-bungarotoxin from human alpha7 nAChRs in the cell line GH(4)C(1) (IC(50) 17 and 23 microM, respectively) and from Lymnaea stagnalis and Aplysia californica AChBPs (IC(50) 2.0-9.0 microM). According to SPR measurements, both isomers bound to immobilized AChBPs and competed with AChBP for immobilized alpha-bungarotoxin (K(d) and IC(50) 2.5-8.2 microM). On Torpedo nAChR, alpha-conotoxin [(125)I]-ImII(W10Y) revealed specific binding (K(d) 1.5-6.1 microM) and could be displaced by alpha-conotoxin ImII, ImIIiso and ImII(W10Y) with IC(50) 2.7, 2.2 and 3.1 microM, respectively. As alpha-cobratoxin and alpha-conotoxin ImI displaced [(125)I]-ImII(W10Y) only at higher concentrations (IC(50)> or = 90 microM), our results indicate that alpha-conotoxin ImII and its congeners have an additional binding site on Torpedo nAChR distinct from the site for agonists/competitive antagonists.
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Affiliation(s)
- Igor E Kasheverov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
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Zamora-Bustillos R, Aguilar MB, Falcón A, Heimer de la Cotera EP. Identification, by RT-PCR, of four novel T-1-superfamily conotoxins from the vermivorous snail Conus spurius from the Gulf of Mexico. Peptides 2009; 30:1396-404. [PMID: 19447151 DOI: 10.1016/j.peptides.2009.05.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2009] [Revised: 05/05/2009] [Accepted: 05/05/2009] [Indexed: 11/27/2022]
Abstract
cDNA was prepared from the venom duct of a single Conus spurius specimen collected near the coast of Campeche, Mexico. From it, PCR products were generated, sequenced, and predicted to encode eight distinct precursors of T-1-conotoxins. These precursors contain five different mature toxins, of which four are novel and one (sr5a) has been previously purified and characterized from the venom of this species. Three of the novel toxins are very similar to sr5a: two have one amino acid substitution at position 8, whereas the other is predicted to have one additional residue at the C-terminus; the fourth toxin has five amino acid substitutions and is predicted to have two additional residues at the C-terminus. In general, the precursors include a 22-residue signal peptide, a 24-residue "pro" region, and a 13- to 16-residue mature toxin region; however, the C-termini of two mature toxin regions are predicted to be altered by post-translational processing. Three precursors lack, in the same positions, 15 amino acid residues included in the "pre" (one residue) and "pro" (14 residues) regions, which suggests the existence of an exon encoding the last signal peptide residue and the first 14 residues of the "pro" region. Phylogenetic analysis indicates that the T-1-conotoxin precursors and mature toxins of C. spurius are more similar to certain precursors and toxins from molluscivorous Conus species than to any precursors and toxins from vermivorous cones. The results reported here will be useful for synthesizing the novel toxins in order to identify their molecular targets.
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Affiliation(s)
- Roberto Zamora-Bustillos
- Laboratorio de Neurofarmacología Marina, Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus Juriquilla, Querétaro 76230, Mexico
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31
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Abstract
The last several decades have seen an explosion of knowledge in the field of structural biology. With critical advances in spectroscopic techniques in examining structures of biomacromolecules, in maturation of molecular biology techniques, as well as vast improvements in computation prowess, protein structures are now being elucidated at an unprecedented rate. In spite of all the recent advances, the protein folding puzzle remains as one of the fundamental biochemical challenges. A facet to this empiric problem is the structural determinants of protein folding. What are the driving forces that pivot a polypeptide chain to a specific conformation amongst the vast conformation space? In this review, we shall discuss some of the structural determinants to protein folding that have been identified in the recent decades.
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Affiliation(s)
- Tse Siang Kang
- The Scripps Research Institute, 10550 North Torrey Pines Road GAC 1200, La Jolla, CA 92037 USA
- Department of Pharmacy, National University of Singapore, 18 Science Drive 4, Block S4, Singapore, 117543 Singapore
| | - R. Manjunatha Kini
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Block S3 #03-17, Singapore, 117543 Singapore
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Townsend A, Livett BG, Bingham JP, Truong HT, Karas JA, O’Donnell P, Williamson NA, Purcell AW, Scanlon D. Mass Spectral Identification of Vc1.1 and Differential Distribution of Conopeptides in the Venom Duct of Conus victoriae. Effect of Post-Translational Modifications and Disulfide Isomerisation on Bioactivity. Int J Pept Res Ther 2009. [DOI: 10.1007/s10989-009-9173-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
Conotoxins are well known for their highly variable structures and functions. Here we report the identification of a novel conotoxin named mr1e from Conus marmoreus. mr1e is composed of 11 amino acid residues cross-linked by two disulfide bonds (CCHSSWCKHLC). The spacing of intercysteine loops in mr1e is exactly the same as that in alpha4/3 conotoxins. However, the native mr1e peptide co-eluted on reverse-phase HPLC with the regioselectively synthesized ribbon disulfide linkage isomer (C1-C4, C2-C3) but not the globular linkage isomer (C1-C3, C2-C4). Although this peptide has the same disulfide connectivity as the chi-conotoxins, their sequences do not share significant homology. Thus, mr1e could be defined as a novel conotoxin family. By intracranial injection into mice, mr1e showed an excitatory effect. The characterization of mr1e certainly enriches our understanding of conotoxins, and also opens an avenue for further structural and functional investigation.
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Affiliation(s)
- Yanfang Wang
- Institute of Protein Research, Tongji University, Shanghai 200092, China
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Peng C, Wu X, Han Y, Yuan D, Chi C, Wang C. Identification of six novel T-1 conotoxins from Conus pulicarius by molecular cloning. Peptides 2007; 28:2116-24. [PMID: 17933431 DOI: 10.1016/j.peptides.2007.08.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2007] [Revised: 08/30/2007] [Accepted: 08/31/2007] [Indexed: 10/22/2022]
Abstract
Cone snails are a group of ancient marine gastropods with highly sophisticated defense and prey strategies using conotoxins in their venom. Conotoxins are a diverse array of small peptides, mostly with multiple disulfide bridges. Using a 3' RACE approach, we identified six novel peptides from the venom ducts of a worm-hunting cone snail Conus pulicarius. These peptides are named Pu5.1-Pu5.6 as their primary structures show the typical pattern of T-1 conotoxin family, a large and diverse group of peptides widely distributed in venom ducts of all major feeding types of Conus. Except for the conserved signal peptide sequences in the precursors and unique arrangement of Cys residues (CC-CC) in mature domains, the six novel T-1 conotoxins show remarkable sequence diversity in their pro and mature regions and are, thus, likely to be functionally diversified. Here, we present a simple and fast strategy of gaining novel disulfide-rich conotoxins via molecular cloning and our detailed sequence analysis will pave the way for the future functional characterization of toxin-receptor interaction.
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Affiliation(s)
- Can Peng
- Institute of Protein Research, College of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai, China
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35
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Mandal AK, Ramasamy MRS, Sabareesh V, Openshaw ME, Krishnan KS, Balaram P. Sequencing of T-superfamily conotoxins from Conus virgo: pyroglutamic acid identification and disulfide arrangement by MALDI mass spectrometry. J Am Soc Mass Spectrom 2007; 18:1396-404. [PMID: 17544293 DOI: 10.1016/j.jasms.2007.04.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2006] [Revised: 04/07/2007] [Accepted: 04/11/2007] [Indexed: 05/15/2023]
Abstract
De novo mass spectrometric sequencing of two Conus peptides, Vi1359 and Vi1361, from the vermivorous cone snail Conus virgo, found off the southern Indian coast, is presented. The peptides, whose masses differ only by 2 Da, possess two disulfide bonds and an amidated C-terminus. Simple chemical modifications and enzymatic cleavage coupled with matrix assisted laser desorption ionization (MALDI) mass spectrometric analysis aided in establishing the sequences of Vi1359, ZCCITIPECCRI-NH(2), and Vi1361, ZCCPTMPECCRI-NH(2), which differ only at residues 4 and 6 (Z = pyroglutamic acid). The presence of the pyroglutamyl residue at the N-terminus was unambiguously identified by chemical hydrolysis of the cyclic amide, followed by esterification. The presence of Ile residues in both the peptides was confirmed from high-energy collision induced dissociation (CID) studies, using the observation of w(n)- and d(n)-ions as a diagnostic. Differential cysteine labeling, in conjunction with MALDI-MS/MS, permitted establishment of disulfide connectivity in both peptides as Cys2-Cys9 and Cys3-Cys10. The cysteine pattern clearly reveals that the peptides belong to the class of T-superfamily conotoxins, in particular the T-1 superfamily.
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Affiliation(s)
- Amit Kumar Mandal
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
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36
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Abstract
Conotoxins are small disulfide-rich peptides from the venom of cone snails. Along with other conopeptides, they target a wide range of membrane receptors, ion channels, and transporters, and because of their high potency and selectivity for defined subtypes of these receptors, they have attracted a great deal of attention recently as leads in drug development. However, like most peptides, conopeptides potentially suffer from the disadvantages of poor absorption, poor stability, or short biological half-lives. Recently, various chemical approaches, including residue substitutions, backbone cyclization, and disulfide-bridge modification, have been reported to increase the stability of conopeptides. These manufactured interventions add to the array of post-translational modifications that occur naturally in conopeptides. They enhance the versatility of these peptides as tools in neuroscience and as drug leads.
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Affiliation(s)
- David J Craik
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
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Jin AH, Brandstaetter H, Nevin ST, Tan CC, Clark RJ, Adams DJ, Alewood PF, Craik DJ, Daly NL. Structure of alpha-conotoxin BuIA: influences of disulfide connectivity on structural dynamics. BMC Struct Biol 2007; 7:28. [PMID: 17445276 DOI: 10.1186/1472-6807-7-28] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2006] [Accepted: 04/20/2007] [Indexed: 12/01/2022]
Abstract
Background α-Conotoxins have exciting therapeutic potential based on their high selectivity and affinity for nicotinic acetylcholine receptors. The spacing between the cysteine residues in α-conotoxins is variable, leading to the classification of sub-families. BuIA is the only α-conotoxin containing a 4/4 cysteine spacing and thus it is of significant interest to examine the structure of this conotoxin. Results In the current study we show the native globular disulfide connectivity of BuIA displays multiple conformations in solution whereas the non-native ribbon isomer has a single well-defined conformation. Despite having multiple conformations in solution the globular form of BuIA displays activity at the nicotinic acetylcholine receptor, contrasting with the lack of activity of the structurally well-defined ribbon isomer. Conclusion These findings are opposite to the general trends observed for α-conotoxins where the native isomers have well-defined structures and the ribbon isomers are generally disordered. This study thus highlights the influence of the disulfide connectivity of BuIA on the dynamics of the three-dimensional structure.
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Abstract
The M-superfamily of conotoxins has a typical Cys framework (-CC-C-C-CC-), and is one of the eight major superfamilies found in the venom of the cone snail. Depending on the number of residues located in the last Cys loop (between Cys4 and Cys5), the M-superfamily family can be divided into four branches, namely M-1, -2, -3 and -4. Recently, two M-1 branch conotoxins (mr3e and tx3a) have been reported to possess a new disulfide bond arrangement between Cys1 and Cys5, Cys2 and Cys4, and Cys3 and Cys6, which is different from those seen in the M-2 and M-4 branches. Here we report the 3D structure of mr3e determined by 2D (1)H NMR in aqueous solution. Twenty converged structures of this peptide were obtained on the basis of 190 distance constraints obtained from NOE connectivities, as well as six varphi dihedral angle, three hydrogen bond, and three disulfide bond constraints. The rmsd values about the averaged coordinates of the backbone atoms were 0.43 +/- 0.19 A. Although mr3e has the same Cys arrangement as M-2 and M-4 conotoxins, it adopts a distinctive backbone conformation with the overall molecule resembling a 'flying bird'. Thus, different disulfide linkages may be employed by conotoxins with the same Cys framework to result in a more diversified backbone scaffold.
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Affiliation(s)
- Wei-Hong Du
- Departments of Chemistry, Renmin University of China and Beijing Normal University, Beijing, China
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39
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Kang TS, Radić Z, Talley TT, Jois SDS, Taylor P, Kini RM. Protein folding determinants: structural features determining alternative disulfide pairing in alpha- and chi/lambda-conotoxins. Biochemistry 2007; 46:3338-55. [PMID: 17315952 PMCID: PMC4778399 DOI: 10.1021/bi061969o] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Alpha-conotoxins isolated from Conus venoms contain 11-19 residues and preferentially fold into the globular conformation that possesses a specific disulfide pairing pattern (C1-3, C2-4). We and others isolated a new family of chi-conotoxins (also called lambda conotoxins) with the conserved cysteine framework of alpha-conotoxins but with alternative disulfide pairing (C1-4, C2-3) resulting in the ribbon conformation. In both families, disulfide pairing and hence folding are important for their biological potency. By comparing the structural differences, we identified potential structural determinants responsible for the folding tendencies of these conotoxins. We examined the role of conserved proline in the first intercysteine loop and the conserved C-terminal amide on folding patterns of synthetic analogues of ImI conotoxin by comparing the isoforms with the regiospecifically synthesized conformers. Deamidation at the C-terminus and substitution of proline in the first intercysteine loop switch the folding pattern from the globular form of alpha-conotoxins to the ribbon form of chi/lambda-conotoxins. The findings are corroborated by reciprocal folding of CMrVIA chi/lambda-conotoxins. Substitution of Lys-6 from the first intercysteine loop of CMrVIA conotoxin with proline, as well as the inclusion of an amidated C-terminal shifted the folding preference of CMrVIA conotoxin from its native ribbon conformation toward the globular conformation. Binding assays of ImI conotoxin analogues with Aplysia and Bulinus acetylcholine binding protein indicate that both these substitutions and their consequent conformational change substantially impact the binding affinity of ImI conotoxin. These results strongly indicate that the first intercysteine loop proline and C-terminal amidation act as conformational switches in alpha- and chi/lambda-conotoxins.
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Affiliation(s)
- Tse Siang Kang
- Protein Science Laboratory, Department of Biological Sciences, National University of Singapore, Singapore 117 543
| | - Zoran Radić
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California at San Diego, La Jolla, California 92093
| | - Todd T. Talley
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California at San Diego, La Jolla, California 92093
| | - Seetharama D. S. Jois
- Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore 117 543
| | - Palmer Taylor
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California at San Diego, La Jolla, California 92093
| | - R. Manjunatha Kini
- Protein Science Laboratory, Department of Biological Sciences, National University of Singapore, Singapore 117 543
- Department of Biochemistry, Medical College of Virginia, Virginia Commonwealth University, Richmond, Virginia 13298
- To whom correspondence to should be addressed at Protein Science Laboratory, Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore 117 543. Tel: (65) 6516-5235. Fax: (65) 67792486.
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40
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Nair SS, Nilsson CL, Emmett MR, Schaub TM, Gowd KH, Thakur SS, Krishnan KS, Balaram P, Marshall AG. De novo sequencing and disulfide mapping of a bromotryptophan-containing conotoxin by Fourier transform ion cyclotron resonance mass spectrometry. Anal Chem 2007; 78:8082-8. [PMID: 17134143 PMCID: PMC2518043 DOI: 10.1021/ac0607764] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
T-1-family conotoxins belong to the T-superfamily and are composed of 10-17 amino acids. They share a common cysteine framework and disulfide connectivity and exhibit unusual posttranslational modifications, such as tryptophan bromination, glutamic acid carboxylation, and threonine glycosylation. We have isolated and characterized a novel peptide, Mo1274, containing 11 amino acids, that shows the same cysteine pattern, -CC-CC, and disulfide linkage as those of the T-1-family members. The complete sequence, GNWCCSARVCC, in which W denotes bromotryptophan, was derived from MS-based de novo sequencing. The FT-ICR MS/MS techniques of electron capture dissociation (ECD), infrared multiphoton dissociation, and collision-induced dissociation served to detect and localize the tryptophan bromination. The bromine contributes a distinctive isotopic distribution in all fragments that contain bromotryptophan. ECD fragmentation results in the loss of bromine and return to the normal isotopic distribution. Disulfide connectivity of Mo1274, between cysteine pairs 1-3 and 2-4, was determined by mass spectrometry in combination with chemical derivatization employing tris(2-carboxyethyl)phosphine, followed by differential alkylation with N-ethylmaleimide and iodoacetamide. The ECD spectra of the native and partially modified peptide reveal a loss of bromine in a process that requires the presence of a disulfide bond.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Alan G. Marshall
- To whom correspondence should be addressed. Telephone: 1−850−644−0529. Fax: 1−850−644−1366. E-mail:
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41
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Brust A, Tickle AE. High-throughput synthesis of conopeptides: a safety-catch linker approach enabling disulfide formation in 96-well format. J Pept Sci 2007; 13:133-41. [PMID: 17160973 DOI: 10.1002/psc.825] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Conotoxins exhibit a high degree of selectivity and potency for a range of pharmacologically relevant targets. The rapid access to libraries of conotoxin analogues, containing multiple intramolecular disulfide bridges for use in drug development, can be a very labor intensive, multi-step task. This work describes a high-throughput method for the synthesis of cystine-bridged conopeptides. Peptides were assembled on a peptide synthesizer employing the Fmoc solid-phase strategy using a safety-catch amide linker (SCAL). Side-chain protecting groups were removed on solid phase before SCAL activation with ammonium iodide in TFA, finally releasing the peptide into the TFA solution. Disulfide bond formation was performed in the cleavage mixture employing DMSO. This improved method allows mixtures of oxidized peptides to be obtained in parallel directly from a peptide synthesizer. A single HPLC purification of the resulting crude oxidized material produced peptides of > 95% purity.
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Affiliation(s)
- Andreas Brust
- Xenome Ltd, 120 Meiers Road, Indooroopilly 4068, Australia.
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42
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Pi C, Liu J, Wang L, Jiang X, Liu Y, Peng C, Chen S, Xu A. Soluble expression, purification and functional identification of a disulfide-rich conotoxin derived from Conus litteratus. J Biotechnol 2007; 128:184-93. [PMID: 17069917 DOI: 10.1016/j.jbiotec.2006.09.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2006] [Revised: 08/31/2006] [Accepted: 09/14/2006] [Indexed: 01/24/2023]
Abstract
Conotoxins are a diverse array of small peptides mostly with multiple disulfide bridges. These peptides become an increasing significant source of neuro-pharmacological probes and drugs as a result of the high selectivity for ion channels and receptors. Usually, the analogue of natural conotoxins is produced by means of chemical synthesis. Here, we present a simple and fast strategy of producing disulfide-rich conotoxins via recombinant expression. By fused with thioredoxin and His tag, a novel O-superfamily conotoxin lt7a was successfully expressed in Escherichia coli and purified, resulting in a high yield of recombinant lt7a about 6 mg/l. The purity of target protein is up to 95% as identified by HPLC results. Whole cell patch-clamp recording revealed that the new conotoxin blocked voltage-sensitive sodium channels in rat dorsal root ganglion neurons, indicating it might be a novel microO-conotoxin.
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Affiliation(s)
- Canhui Pi
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory of Therapeutic Functional Genes, Open Laboratory for Marine Functional Genomics, Department of Biochemistry, College of Life Sciences, Sun Yat-sen University, People's Republic of China
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43
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Luo S, Zhangsun D, Lin Q, Xie L, Wu Y, Zhu X. Sequence diversity of O-superfamily conopetides from Conus marmoreus native to Hainan. Peptides 2006; 27:3058-68. [PMID: 17011667 DOI: 10.1016/j.peptides.2006.08.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2006] [Revised: 08/18/2006] [Accepted: 08/22/2006] [Indexed: 10/24/2022]
Abstract
The full-length cDNAs of six new O-superfamily conotoxins (CTX) were cloned and sequenced from Conus marmoreus native to Hainan in China South Sea using RT-PCR and 3'-RACE. Six novel conotoxin precursors encoded by these cDNAs consist of three typical regions of signal, pro-peptide and mature peptide. All the six toxin regions share a common O-superfamily cysteine pattern (C-C-CC-C-C, with three disulfide bridges). The predicted precursors are composed of 73-88 amino acids, and the predicted mature peptides consist of 26-34 amino acids. Phylogenetic analysis of new conotoxins from C. marmoreus from the present study and published homologue T-superfamily sequences from other Conus species was performed systematically. Patterns of sequence divergence for three regions of signal, pro-region and mature peptides, as well as Cys codon usage define the major O-superfamily branches and suggest how these separate branches arose. Percent identities of the amino acid sequences of the signal region exhibited high conservation, whereas the sequences of the mature peptides ranged from almost identical to highly divergent between inter- and intra-species. Notably, the diversity of the pro-region was also high with intermediate divergence between that observed in signal and toxin regions. Amino acid sequences and their mode of action (target) of previously identified conotoxins from molluscivorous C. marmoreus for the known conotoxins classes are discussed in detail. The data presented are new and should pave the way for chemical synthesis of these unique conotoxins for to allow determination of the molecular targets of these peptides, and also to provide clues for a better understanding of the phylogeny of these peptides.
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Affiliation(s)
- Sulan Luo
- Key Laboratory for Tropical Biology Resources, Ministry of Education, Ocean College, Center for Experimental Biotechnology, Hainan University, Haikou, Hainan 570228, China. luosulan@
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Abstract
The O-superfamily of conotoxins includes several subfamilies with different pharmacological targets, all of which are voltage-gated ion channels and distributed widely in varied Conus species. The venom components from any Conus species are quite distinct from those of other species. Seven novel O-superfamily peptides were identified by cDNA cloning from the three vermivorous Conus species of C. betulinus, C. lividus and C. caracteristicus native to Hainan. They share three common signal sequences, and a conserved arrangement of cysteine residues (C-C-CC-C-C). Phylogenetic analysis of newly found conotoxins in this study and known homologue O-superfamily sequences from the other Conus species was performed systematically. Divergence and percentage identity of the amino acid sequences of the signal regions suggest that the novel conotoxins described in this investigation belong to the three broad clades: MSGL, ME-QK and MKLT, each of which has its own characteristic signature signal sequence and cysteine codon conservation. Relative to this work, it is noted that O-superfamily conotoxins are not well represented from vermivorous species. The elucidated cDNAs of these newly found vermivorous toxins would facilitate a better understanding for basic research and drug discovery.
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Affiliation(s)
- Dongting Zhangsun
- Key Laboratory for Tropical Biology Resources (MOE), Ocean College, Center for Experimental Biotechnology, Hainan University, Haikou Hainan 570228, China
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45
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Lovelace ES, Armishaw CJ, Colgrave ML, Wahlstrom ME, Alewood PF, Daly NL, Craik DJ. Cyclic MrIA: A Stable and Potent Cyclic Conotoxin with a Novel Topological Fold that Targets the Norepinephrine Transporter. J Med Chem 2006; 49:6561-8. [PMID: 17064074 DOI: 10.1021/jm060299h] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Conotoxins, disulfide-rich peptides from the venom of cone snails, have created much excitement over recent years due to their potency and specificity for ion channels and their therapeutic potential. One recently identified conotoxin, MrIA, a 13-residue member of the chi-conotoxin family, inhibits the human norepinephrine transporter (NET) and has potential applications in the treatment of pain. In the current study, we show that the beta-hairpin structure of native MrIA is retained in a synthetic cyclic version, as is biological activity at the NET. Furthermore, the cyclic version has increased resistance to trypsin digestion relative to the native peptide, an intriguing result because the cleavage site for the trypsin is not close to the cyclization site. The use of peptides as drugs is generally hampered by susceptibility to proteolysis, and so, the increase in enzymatic stability against trypsin observed in the current study may be useful in improving the therapeutic potential of MrIA. Furthermore, the structure reported here for cyclic MrIA represents a new topology among a growing number of circular disulfide-rich peptides.
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Affiliation(s)
- Erica S Lovelace
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia
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Nair SS, Romanuka J, Billeter M, Skjeldal L, Emmett MR, Nilsson CL, Marshall AG. Structural characterization of an unusually stable cyclic peptide, kalata B2 from Oldenlandia affinis. Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics 2006; 1764:1568-76. [PMID: 16987719 DOI: 10.1016/j.bbapap.2006.07.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2006] [Revised: 06/19/2006] [Accepted: 07/19/2006] [Indexed: 11/19/2022]
Abstract
Kalata peptides are isolated from an African medicinal plant, Oldenlandia affinis, an aqueous decoction of which can be ingested to accelerate uterine contraction during childbirth. The closely packed disulfide core of kalata peptides confers unusual stability against thermal, chemical, and enzymatic degradation. The molecular arrangement may hamper NMR-assisted disulfide connectivity assignment. We have combined NMR with high-resolution mass spectrometry (MS) and MS/MS of native and chemically derivatized kalata B2 to determine its amino acid sequence and disulfide connectivity. Infrared multiphoton dissociation establishes the disulfide bond linkages in kalata B2 as I-IV, II-V and III-VI.
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Abstract
alpha-Conotoxins possess a conserved four-cysteine framework and disulfide linkages (C(1)(-)(3), C(2)(-)(4)) that fold toward the globular conformation with absolute fidelity. Despite the presence of a similar conserved set of cysteine framework, chi/lambda-conotoxins adopt an alternate disulfide-pairing (C(1)(-)(4), C(2)(-)(3)) and its consequent ribbon conformation, exhibiting distinct biological activities from alpha-conotoxins. chi/lambda-Conotoxin CMrVIA (VCCGYKLCHOC-COOH) isolated from the venom of Conus marmoreus natively exists in the ribbon conformation and induces seizures in mice at a potency that is of three orders higher than the non-native globular form. We have chemically synthesized two isoforms of CMrVIA conotoxin in the ribbon and globular conformation and determined their structures by (1)H NMR spectroscopy. The ribbon (PDB ID 2B5P) and globular conformations (PBD ID 2B5Q) were calculated to have paired-wise backbone RMSDs of 0.48 +/- 0.1 and 0.58 +/- 0.1 A respectively. Unlike the native globular alpha-conotoxins, the globular canonical form of CMrVIA chi/lambda-conotoxin exhibited heterogeneity in its solution structure as noted by the presence of minor conformers and poorer RMSD of structure calculation. Paired-wise backbone comparison between the native ribbon and the non-native globular form of CMrVIA conotoxin revealed an RMSD of 4.73 A, emphasizing their distinct conformational differences. These structural data are essential for the understanding of the structure-function activity of chi/lambda-conotoxins, as well as unraveling the folding propensities of these short peptide toxins.
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Affiliation(s)
- Tse Siang Kang
- Protein Science Laboratory, Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Block S3 #03-17 Singapore
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Marx UC, Daly NL, Craik DJ. NMR of conotoxins: structural features and an analysis of chemical shifts of post-translationally modified amino acids. Magn Reson Chem 2006; 44 Spec No:S41-50. [PMID: 16826542 DOI: 10.1002/mrc.1821] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Conotoxins are small conformationally constrained peptides found in the venom of marine snails of the genus Conus. They are usually cysteine rich and frequently contain a high degree of post-translational modifications such as C-terminal amidation, hydroxylation, carboxylation, bromination, epimerisation and glycosylation. Here we review the role of NMR in determining the three-dimensional structures of conotoxins and also provide a compilation and analysis of 1H and 13C chemical shifts of post-translationally modified amino acids and compare them with data from common amino acids. This analysis provides a reference source for chemical shifts of post-translationally modified amino acids.
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Affiliation(s)
- Ute C Marx
- Institute for Molecular Bioscience and Australian Research Council Special Research Centre for Functional and Applied Genomics, University of Queensland, Brisbane QLD 4072, Australia
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Bulaj G, Zhang MM, Green BR, Fiedler B, Layer RT, Wei S, Nielsen JS, Low SJ, Klein BD, Wagstaff JD, Chicoine L, Harty TP, Terlau H, Yoshikami D, Olivera BM. Synthetic μO-Conotoxin MrVIB Blocks TTX-Resistant Sodium Channel NaV1.8 and Has a Long-Lasting Analgesic Activity†. Biochemistry 2006; 45:7404-14. [PMID: 16752929 DOI: 10.1021/bi060159+] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
MuO-conotoxin MrVIB is a blocker of voltage-gated sodium channels, including TTX-sensitive and -resistant subtypes. A comprehensive characterization of this peptide has been hampered by the lack of sufficient synthetic material. Here, we describe the successful chemical synthesis and oxidative folding of MrVIB that has made an investigation of the pharmacological properties and therapeutic potential of the peptide feasible. We show for the first time that synthetic MrVIB blocks rat NaV1.8 sodium channels and has potent and long-lasting local anesthetic effects when tested in two pain assays in rats. Furthermore, MrVIB can block propagation of action potentials in A- and C-fibers in sciatic nerve as well as skeletal muscle in isolated preparations from rat. Our work provides the first example of analgesia produced by a conotoxin that blocks sodium channels. The emerging diversity of antinociceptive mechanisms targeted by different classes of conotoxins is discussed.
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Affiliation(s)
- Grzegorz Bulaj
- Department of Biology, The University of Utah, Salt Lake City, Utah 84112, USA.
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Abstract
The full-length cDNAs of two novel T-superfamily conotoxins, Lp5.1 and Lp5.2, were cloned from a vermivorous cone snail Conus leopardus using 3'/5'-rapid amplification of cDNA ends. The cDNA of Lp5.1 encodes a precursor of 65 residues, including a 22-residue signal peptide, a 28-residue propeptide and a 15-residue mature peptide. Lp5.1 is processed at the common signal site-X-Arg- immediately before the mature peptide sequences. In the case of Lp5.2, the precursor includes a 25-residue signal peptide and a 43-residue sequence comprising the propeptide and mature peptide, which is probably cleaved to yield a 29-residue propeptide and a 14-residue mature toxin. Although these two conotoxins share a similar signal sequence and a conserved disulfide pattern with the known T-superfamily, the pro-region and mature peptides are of low identity, especially Lp5.2 with an identity as low as 10.7% compared with the reference Mr5.1a. The elucidated cDNAs of these two toxins will facilitate a better understanding of the species distribution, the sequence diversity of T-superfamily conotoxins, the special gene structure and the evolution of these peptides.
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Affiliation(s)
- Wei-Hua Chen
- Institute of Protein Research, Tongji University, Shanghai 200092, China
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