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Fiorotti HB, Figueiredo SG, Campos FV, Pimenta DC. Cone snail species off the Brazilian coast and their venoms: a review and update. J Venom Anim Toxins Incl Trop Dis 2023; 29:e20220052. [PMID: 36756364 PMCID: PMC9897318 DOI: 10.1590/1678-9199-jvatitd-2022-0052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 12/14/2022] [Indexed: 01/31/2023] Open
Abstract
The genus Conus includes over 900 species of marine invertebrates known as cone snails, whose venoms are among the most powerful described so far. This potency is mainly due to the concerted action of hundreds of small bioactive peptides named conopeptides, which target different ion channels and membrane receptors and thus interfere with crucial physiological processes. By swiftly harpooning and injecting their prey and predators with such deadly cocktails, the slow-moving cone snails guarantee their survival in the harsh, competitive marine environment. Each cone snail species produces a unique venom, as the mature sequences of conopeptides from the venoms of different species share very little identity. This biochemical diversity, added to the numerous species and conopeptides contained in their venoms, results in an immense biotechnological and therapeutic potential, still largely unexplored. That is especially true regarding the bioprospection of the venoms of cone snail species found off the Brazilian coast - a region widely known for its biodiversity. Of the 31 species described in this region so far, only four - Conus cancellatus, Conus regius, Conus villepinii, and Conus ermineus - have had their venoms partially characterized, and, although many bioactive molecules have been identified, only a few have been actually isolated and studied. In addition to providing an overview on all the cone snail species found off the Brazilian coast to date, this review compiles the information on the structural and pharmacological features of conopeptides and other molecules identified in the venoms of the four aforementioned species, paving the way for future studies.
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Affiliation(s)
- Helena B. Fiorotti
- Laboratory of Biochemistry and Biophysics, Butantan Institute, São
Paulo, SP, Brazil.,Graduate Program in Biochemistry, Laboratory of Protein Chemistry
(LQP), Federal University of Espírito Santo, Vitória, ES, Brazil
| | - Suely G. Figueiredo
- Graduate Program in Biochemistry, Laboratory of Protein Chemistry
(LQP), Federal University of Espírito Santo, Vitória, ES, Brazil
| | - Fabiana V. Campos
- Laboratory of Biochemistry and Biophysics, Butantan Institute, São
Paulo, SP, Brazil.,Graduate Program in Biochemistry, Laboratory of Protein Chemistry
(LQP), Federal University of Espírito Santo, Vitória, ES, Brazil
| | - Daniel C. Pimenta
- Laboratory of Biochemistry and Biophysics, Butantan Institute, São
Paulo, SP, Brazil.,Correspondence:
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2
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Depuydt AS, Peigneur S, Tytgat J. Review: HCN Channels in the Heart. Curr Cardiol Rev 2022; 18:e040222200836. [PMID: 35125083 PMCID: PMC9893134 DOI: 10.2174/1573403x18666220204142436] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 12/13/2021] [Accepted: 12/23/2021] [Indexed: 11/22/2022] Open
Abstract
Pacemaker cells are the basis of rhythm in the heart. Cardiovascular diseases, and in particular, arrhythmias are a leading cause of hospital admissions and have been implicated as a cause of sudden death. The prevalence of people with arrhythmias will increase in the next years due to an increase in the ageing population and risk factors. The current therapies are limited, have a lot of side effects, and thus, are not ideal. Pacemaker channels, also called hyperpolarizationactivated cyclic nucleotide-gated (HCN) channels, are the molecular correlate of the hyperpolarization- activated current, called Ih (from hyperpolarization) or If (from funny), that contribute crucially to the pacemaker activity in cardiac nodal cells and impulse generation and transmission in neurons. HCN channels have emerged as interesting targets for the development of drugs, in particular, to lower the heart rate. Nonetheless, their pharmacology is still rather poorly explored in comparison to many other voltage-gated ion channels or ligand-gated ion channels. Ivabradine is the first and currently the only clinically approved compound that specifically targets HCN channels. The therapeutic indication of ivabradine is the symptomatic treatment of chronic stable angina pectoris in patients with coronary artery disease with a normal sinus rhythm. Several other pharmacological agents have been shown to exert an effect on heart rate, although this effect is not always desired. This review is focused on the pacemaking process taking place in the heart and summarizes the current knowledge on HCN channels.
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Affiliation(s)
- Anne-Sophie Depuydt
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg, O&N2, PO Box 922, Herestraat 49, 3000Leuven, Belgium
| | - Steve Peigneur
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg, O&N2, PO Box 922, Herestraat 49, 3000Leuven, Belgium
| | - Jan Tytgat
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg, O&N2, PO Box 922, Herestraat 49, 3000Leuven, Belgium
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Bjørn-Yoshimoto WE, Ramiro IBL, Yandell M, McIntosh JM, Olivera BM, Ellgaard L, Safavi-Hemami H. Curses or Cures: A Review of the Numerous Benefits Versus the Biosecurity Concerns of Conotoxin Research. Biomedicines 2020; 8:E235. [PMID: 32708023 PMCID: PMC7460000 DOI: 10.3390/biomedicines8080235] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/17/2020] [Accepted: 07/19/2020] [Indexed: 01/18/2023] Open
Abstract
Conotoxins form a diverse group of peptide toxins found in the venom of predatory marine cone snails. Decades of conotoxin research have provided numerous measurable scientific and societal benefits. These include their use as a drug, diagnostic agent, drug leads, and research tools in neuroscience, pharmacology, biochemistry, structural biology, and molecular evolution. Human envenomations by cone snails are rare but can be fatal. Death by envenomation is likely caused by a small set of toxins that induce muscle paralysis of the diaphragm, resulting in respiratory arrest. The potency of these toxins led to concerns regarding the potential development and use of conotoxins as biological weapons. To address this, various regulatory measures have been introduced that limit the use and access of conotoxins within the research community. Some of these regulations apply to all of the ≈200,000 conotoxins predicted to exist in nature of which less than 0.05% are estimated to have any significant toxicity in humans. In this review we provide an overview of the many benefits of conotoxin research, and contrast these to the perceived biosecurity concerns of conotoxins and research thereof.
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Affiliation(s)
- Walden E. Bjørn-Yoshimoto
- Department of Biomedical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark; (W.E.B.-Y.); (I.B.L.R.)
| | - Iris Bea L. Ramiro
- Department of Biomedical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark; (W.E.B.-Y.); (I.B.L.R.)
| | - Mark Yandell
- Eccles Institute of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA;
- Utah Center for Genetic Discovery, University of Utah, Salt Lake City, UT 84112, USA
| | - J. Michael McIntosh
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA; (J.M.M.); (B.M.O.)
- George E. Whalen Veterans Affairs Medical Center, Salt Lake City, UT 84148, USA
- Department of Psychiatry, University of Utah, Salt Lake City, UT 84108, USA
| | - Baldomero M. Olivera
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA; (J.M.M.); (B.M.O.)
| | - Lars Ellgaard
- Department of Biology, Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, 2200 Copenhagen N, Denmark;
| | - Helena Safavi-Hemami
- Department of Biomedical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark; (W.E.B.-Y.); (I.B.L.R.)
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA; (J.M.M.); (B.M.O.)
- Department of Biochemistry, University of Utah, Salt Lake City, UT 84112, USA
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4
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Sudewi AA, Susilawathi NM, Mahardika BK, Mahendra AN, Pharmawati M, Phuong MA, Mahardika GN. Selecting Potential Neuronal Drug Leads from Conotoxins of Various Venomous Marine Cone Snails in Bali, Indonesia. ACS OMEGA 2019; 4:19483-19490. [PMID: 31763573 PMCID: PMC6868881 DOI: 10.1021/acsomega.9b03122] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 10/23/2019] [Indexed: 06/10/2023]
Abstract
Many conotoxins, natural peptides of marine cone snails, have been identified to target neurons. Here, we provide data on pharmacological families of the conotoxins of 11 species of cone snails collected in Bali. The identified definitive pharmacological families possibly targeting neuronal tissues were α (alpha), ι (iota), κ (kappa), and ρ (rho). These classes shall target nicotinic acetylcholine receptors, voltage-gated Na channels, voltage-gated K channels, and α1-adrenoceptors, respectively. The VI/VII-O3 conotoxins might be prospected as an inhibitor of N-methyl-d-aspartate. Con-ikot-ikot could be applied as an α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor blocker medicine. The definitive pharmacology classes of conotoxins as well as those yet to be elucidated need to be further established and verified.
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Affiliation(s)
- Anak A.
R. Sudewi
- Neurology
Department of the Faculty of Medicine and Pharmacology Department of the Faculty
of Medicine, Udayana University, Jl. Sudirman, Denpasar 80226, Bali, Indonesia
| | - Ni M. Susilawathi
- Neurology
Department of the Faculty of Medicine and Pharmacology Department of the Faculty
of Medicine, Udayana University, Jl. Sudirman, Denpasar 80226, Bali, Indonesia
| | - Bayu K. Mahardika
- The
Animal Biomedical and Molecular Biology Laboratory, Udayana University of Bali, Jl. Sesetan-Markisa 6, Denpasar 80223, Bali, Indonesia
| | - Agung N. Mahendra
- Neurology
Department of the Faculty of Medicine and Pharmacology Department of the Faculty
of Medicine, Udayana University, Jl. Sudirman, Denpasar 80226, Bali, Indonesia
| | - Made Pharmawati
- Faculty
of Mathematic and Natural Sciences, Udayana
University of Bali, Kampus
Bukit Jimbaran, Badung 80361, Bali, Indonesia
| | - Mark A. Phuong
- Department
of Ecology and Evolutionary Biology, University
of California, Los Angeles, Los
Angeles 90095, California, United States
| | - Gusti N. Mahardika
- The
Animal Biomedical and Molecular Biology Laboratory, Udayana University of Bali, Jl. Sesetan-Markisa 6, Denpasar 80223, Bali, Indonesia
- The Indonesian
Biodiversity Research Center, Jl. Sudirman, Denpasar 80225, Bali, Indonesia
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5
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Morales Duque H, Campos Dias S, Franco OL. Structural and Functional Analyses of Cone Snail Toxins. Mar Drugs 2019; 17:md17060370. [PMID: 31234371 PMCID: PMC6628382 DOI: 10.3390/md17060370] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 06/16/2019] [Accepted: 06/17/2019] [Indexed: 12/12/2022] Open
Abstract
Cone snails are marine gastropod mollusks with one of the most powerful venoms in nature. The toxins, named conotoxins, must act quickly on the cone snails´ prey due to the fact that snails are extremely slow, reducing their hunting capability. Therefore, the characteristics of conotoxins have become the object of investigation, and as a result medicines have been developed or are in the trialing process. Conotoxins interact with transmembrane proteins, showing specificity and potency. They target ion channels and ionotropic receptors with greater regularity, and when interaction occurs, there is immediate physiological decompensation. In this review we aimed to evaluate the structural features of conotoxins and the relationship with their target types.
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Affiliation(s)
- Harry Morales Duque
- Centro de Análises Proteômicas e Bioquímicas, Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília-DF 70.790-160, Brazil.
| | - Simoni Campos Dias
- Centro de Análises Proteômicas e Bioquímicas, Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília-DF 70.790-160, Brazil.
| | - Octávio Luiz Franco
- Centro de Análises Proteômicas e Bioquímicas, Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília-DF 70.790-160, Brazil.
- S-inova Biotech, Programa de Pós-Graduação em Biotecnologia, Universidade Católica Dom Bosco, Campo Grande-MS 79.117-900, Brazil.
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6
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Yao G, Peng C, Zhu Y, Fan C, Jiang H, Chen J, Cao Y, Shi Q. High-Throughput Identification and Analysis of Novel Conotoxins from Three Vermivorous Cone Snails by Transcriptome Sequencing. Mar Drugs 2019; 17:md17030193. [PMID: 30917600 PMCID: PMC6471451 DOI: 10.3390/md17030193] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 03/19/2019] [Accepted: 03/25/2019] [Indexed: 12/13/2022] Open
Abstract
The venom of each Conus species consists of a diverse array of neurophysiologically active peptides, which are mostly unique to the examined species. In this study, we performed high-throughput transcriptome sequencing to extract and analyze putative conotoxin transcripts from the venom ducts of 3 vermivorous cone snails (C. caracteristicus, C. generalis, and C. quercinus), which are resident in offshore waters of the South China Sea. In total, 118, 61, and 48 putative conotoxins (across 22 superfamilies) were identified from the 3 Conus species, respectively; most of them are novel, and some possess new cysteine patterns. Interestingly, a series of 45 unassigned conotoxins presented with a new framework of C-C-C-C-C-C, and their mature regions were sufficiently distinct from any other known conotoxins, most likely representing a new superfamily. O- and M-superfamily conotoxins were the most abundant in transcript number and transcription level, suggesting their critical roles in the venom functions of these vermivorous cone snails. In addition, we identified numerous functional proteins with potential involvement in the biosynthesis, modification, and delivery process of conotoxins, which may shed light on the fundamental mechanisms for the generation of these important conotoxins within the venom duct of cone snails.
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Affiliation(s)
- Ge Yao
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Chao Peng
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China.
| | - Yabing Zhu
- BGI Genomics, BGI-Shenzhen, Shenzhen 518083, China.
| | - Chongxu Fan
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Hui Jiang
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Jisheng Chen
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Ying Cao
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Qiong Shi
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China.
- Laboratory of Aquatic Genomics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China.
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7
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Conotoxins as Tools to Understand the Physiological Function of Voltage-Gated Calcium (Ca V) Channels. Mar Drugs 2017; 15:md15100313. [PMID: 29027927 PMCID: PMC5666421 DOI: 10.3390/md15100313] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 09/06/2017] [Accepted: 10/04/2017] [Indexed: 12/29/2022] Open
Abstract
Voltage-gated calcium (CaV) channels are widely expressed and are essential for the completion of multiple physiological processes. Close regulation of their activity by specific inhibitors and agonists become fundamental to understand their role in cellular homeostasis as well as in human tissues and organs. CaV channels are divided into two groups depending on the membrane potential required to activate them: High-voltage activated (HVA, CaV1.1–1.4; CaV2.1–2.3) and Low-voltage activated (LVA, CaV3.1–3.3). HVA channels are highly expressed in brain (neurons), heart, and adrenal medulla (chromaffin cells), among others, and are also classified into subtypes which can be distinguished using pharmacological approaches. Cone snails are marine gastropods that capture their prey by injecting venom, “conopeptides”, which cause paralysis in a few seconds. A subset of conopeptides called conotoxins are relatively small polypeptides, rich in disulfide bonds, that target ion channels, transporters and receptors localized at the neuromuscular system of the animal target. In this review, we describe the structure and properties of conotoxins that selectively block HVA calcium channels. We compare their potency on several HVA channel subtypes, emphasizing neuronal calcium channels. Lastly, we analyze recent advances in the therapeutic use of conotoxins for medical treatments.
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8
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Huang Y, Peng C, Yi Y, Gao B, Shi Q. A Transcriptomic Survey of Ion Channel-Based Conotoxins in the Chinese Tubular Cone Snail (Conus betulinus). Mar Drugs 2017; 15:md15070228. [PMID: 28718820 PMCID: PMC5532670 DOI: 10.3390/md15070228] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 07/10/2017] [Accepted: 07/13/2017] [Indexed: 02/06/2023] Open
Abstract
Conotoxins in the venom of cone snails (Conus spp.) are a mixture of active peptides that work as blockers, agonists, antagonists, or inactivators of various ion channels. Recently we reported a high-throughput method to identify 215 conotoxin transcripts from the Chinese tubular cone snail, C. betulinus. Here, based on the previous datasets of four transcriptomes from three venom ducts and one venom bulb, we explored ion channel-based conotoxins and predicted their related ion channel receptors. Homologous analysis was also performed for the most abundant ion channel protein, voltage-gated potassium (Kv; with Kv1.1 as the representative), and the most studied ion channel receptor, nicotinic acetylcholine receptor (nAChR; with α2-nAChR as the representative), in different animals. Our transcriptomic survey demonstrated that ion channel-based conotoxins and related ion channel proteins/receptors transcribe differentially between the venom duct and the venom bulb. In addition, we observed that putative κ-conotoxins were the most common conotoxins with the highest transcription levels in the examined C. betulinus. Furthermore, Kv1.1 and α2-nAChR were conserved in their functional domains of deduced protein sequences, suggesting similar effects of conotoxins via the ion channels in various species, including human beings. In a word, our present work suggests a high-throughput way to develop conotoxins as potential drugs for treatment of ion channel-associated human diseases.
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Affiliation(s)
- Yu Huang
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen 518083, China.
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China.
| | - Chao Peng
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China.
| | - Yunhai Yi
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen 518083, China.
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China.
| | - Bingmiao Gao
- Hainan Provincial Key Laboratory of Research and Development of Tropical Medicinal Plants, Hainan Medical University, Haikou 571199, China.
| | - Qiong Shi
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen 518083, China.
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China.
- Laboratory of Aquatic Genomics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China.
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The Venom Repertoire of Conus gloriamaris (Chemnitz, 1777), the Glory of the Sea. Mar Drugs 2017; 15:md15050145. [PMID: 28531118 PMCID: PMC5450551 DOI: 10.3390/md15050145] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 05/15/2017] [Accepted: 05/17/2017] [Indexed: 12/15/2022] Open
Abstract
The marine cone snail Conus gloriamaris is an iconic species. For over two centuries, its shell was one of the most prized and valuable natural history objects in the world. Today, cone snails have attracted attention for their remarkable venom components. Many conotoxins are proving valuable as research tools, drug leads, and drugs. In this article, we present the venom gland transcriptome of C. gloriamaris, revealing this species' conotoxin repertoire. More than 100 conotoxin sequences were identified, representing a valuable resource for future drug discovery efforts.
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Wu X, Huang Y, Kaas Q, Craik DJ. Cyclisation of Disulfide‐Rich Conotoxins in Drug Design Applications. European J Org Chem 2016. [DOI: 10.1002/ejoc.201600402] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Xiaosa Wu
- Institute for Molecular BioscienceThe University of Queensland306 Carmody Road (Building 80)4072BrisbaneAustralia
| | - Yen‐Hua Huang
- Institute for Molecular BioscienceThe University of Queensland306 Carmody Road (Building 80)4072BrisbaneAustralia
| | - Quentin Kaas
- Institute for Molecular BioscienceThe University of Queensland306 Carmody Road (Building 80)4072BrisbaneAustralia
| | - David J. Craik
- Institute for Molecular BioscienceThe University of Queensland306 Carmody Road (Building 80)4072BrisbaneAustralia
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11
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Bernáldez J, Jiménez S, González LJ, Ferro JN, Soto E, Salceda E, Chávez D, Aguilar MB, Licea-Navarro A. A New Member of Gamma-Conotoxin Family Isolated from Conus princeps Displays a Novel Molecular Target. Toxins (Basel) 2016; 8:39. [PMID: 26861393 PMCID: PMC4773792 DOI: 10.3390/toxins8020039] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 01/22/2016] [Accepted: 01/25/2016] [Indexed: 11/16/2022] Open
Abstract
A novel conotoxin, named as PiVIIA, was isolated from the venom of Conus princeps, a marine predatory cone snail collected in the Pacific Southern Coast of Mexico. Chymotryptic digest of the S-alkylated peptide in combination with liquid chromatography coupled to tandem mass spectrometry, were used to define the sequencing of this peptide. Eleven N-terminal amino acids were verified by automated Edman degradation. PiVIIA is a 25-mer peptide (CDAOTHYCTNYWγCCSGYCγHSHCW) with six cysteine residues forming three disulphide bonds, a hydroxyproline (O) and two gamma carboxyglutamic acid (γ) residues. Based on the arrangement of six Cys residues (C-C-CC-C-C), this conotoxin might belong to the O2-superfamily. Moreover, PiVIIA has a conserved motif (-γCCS-) that characterizes γ-conotoxins from molluscivorous Conus. Peptide PiVIIA has 45% sequence identity with γ-PnVIIA—the prototype of this family. Biological activity of PiVIIA was assessed by voltage-clamp recording in rat dorsal root ganglion neurons. Perfusion of PiVIIA in the µM range produces a significant increase in the Ca2+ currents, without significantly modifying the Na+, K+ or proton-gated acid sensing ionic currents. These results indicate that PiVIIA is a new conotoxin whose activity deserves further studies to define its potential use as a positive modulator of neuronal activity.
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Affiliation(s)
- Johanna Bernáldez
- Departamento de Innovación Biomédica, CICESE, Carretera Ensenada-Tijuana 3918, Ensenada, Baja California, C.P. 22860, Mexico.
| | - Samanta Jiménez
- Departamento de Innovación Biomédica, CICESE, Carretera Ensenada-Tijuana 3918, Ensenada, Baja California, C.P. 22860, Mexico.
| | - Luis Javier González
- Laboratorio de Espectrometría de Masas, Departamento de Proteómica, Centro de Ingeniería Genética y Biotecnología, Avenida 31 e/158 y 190, Cubanacán, Playa, PO Box 6162. C.P. 10600, La Habana, Cuba.
| | - Jesús Noda Ferro
- Laboratorio de Espectrometría de Masas, Departamento de Proteómica, Centro de Ingeniería Genética y Biotecnología, Avenida 31 e/158 y 190, Cubanacán, Playa, PO Box 6162. C.P. 10600, La Habana, Cuba.
| | - Enrique Soto
- Instituto de Fisiología, Benemerita Universidad de Puebla, 14 sur 6301, CU, San Manuel, Puebla, Pue, C.P. 72570, Mexico.
| | - Emilio Salceda
- Instituto de Fisiología, Benemerita Universidad de Puebla, 14 sur 6301, CU, San Manuel, Puebla, Pue, C.P. 72570, Mexico.
| | - Daniela Chávez
- Departamento de Innovación Biomédica, CICESE, Carretera Ensenada-Tijuana 3918, Ensenada, Baja California, C.P. 22860, Mexico.
| | - Manuel B Aguilar
- Laboratorio de Neurofarmacología Marina, Departamento de Neurobiología Celular y Molecular, UNAM, Juriquilla, Queretaro, C.P. 76230, Mexico.
| | - Alexei Licea-Navarro
- Departamento de Innovación Biomédica, CICESE, Carretera Ensenada-Tijuana 3918, Ensenada, Baja California, C.P. 22860, Mexico.
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Abstract
INTRODUCTION Conotoxins are a large family of bioactive peptides derived from cone snail venom. They target specific classes of ion channels and other membrane proteins and may have therapeutic value, primarily in the management of pain. AREAS COVERED The authors surveyed the US patent literature covering conotoxins, and their potential therapeutic applications. They describe the various subclasses of conotoxins that are the subject of current patent applications and their therapeutic indications. Limitations that may preclude broader application of these molecules are discussed and strategies for overcoming these limitations are presented. EXPERT OPINION Despite more than 25 years of intense global conotoxin research, only one molecule has successfully reached the market. Several other conotoxin-derived candidates failed in clinical trials, indicating that 'from the bench into the clinic' translation has been more difficult than originally anticipated. Nevertheless, we are optimistic that the potent activities of these molecules and the potential for improving their biopharmaceutical properties may lead to next-generation drug candidates with favorable pharmacological properties.
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Affiliation(s)
- Thomas Durek
- a The University of Queensland, Institute for Molecular Bioscience , Brisbane 4072, QLD, Australia
| | - David J Craik
- a The University of Queensland, Institute for Molecular Bioscience , Brisbane 4072, QLD, Australia
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13
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Conotoxin gene superfamilies. Mar Drugs 2014; 12:6058-101. [PMID: 25522317 PMCID: PMC4278219 DOI: 10.3390/md12126058] [Citation(s) in RCA: 130] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 11/29/2014] [Accepted: 12/04/2014] [Indexed: 12/16/2022] Open
Abstract
Conotoxins are the peptidic components of the venoms of marine cone snails (genus Conus). They are remarkably diverse in terms of structure and function. Unique potency and selectivity profiles for a range of neuronal targets have made several conotoxins valuable as research tools, drug leads and even therapeutics, and has resulted in a concerted and increasing drive to identify and characterise new conotoxins. Conotoxins are translated from mRNA as peptide precursors, and cDNA sequencing is now the primary method for identification of new conotoxin sequences. As a result, gene superfamily, a classification based on precursor signal peptide identity, has become the most convenient method of conotoxin classification. Here we review each of the described conotoxin gene superfamilies, with a focus on the structural and functional diversity present in each. This review is intended to serve as a practical guide to conotoxin superfamilies and to facilitate interpretation of the increasing number of conotoxin precursor sequences being identified by targeted-cDNA sequencing and more recently high-throughput transcriptome sequencing.
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14
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Thapa P, Espiritu MJ, Cabalteja CC, Bingham JP. Conotoxins and their regulatory considerations. Regul Toxicol Pharmacol 2014; 70:197-202. [PMID: 25013992 DOI: 10.1016/j.yrtph.2014.06.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 06/29/2014] [Accepted: 06/30/2014] [Indexed: 01/21/2023]
Abstract
Venom derived peptides from marine cone snails, conotoxins, have demonstrated unique pharmacological targeting properties that have been pivotal in advancing medical research. The awareness of their true toxic origins and potent pharmacological nature is emphasized by their 'select agent' classification by the US Centers for Disease Control and Prevention. We briefly introduce the biochemical and pharmacological aspects of conotoxins, highlighting current advancements into their biological engineering, and provide details to the present regulations that govern their use in research.
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Affiliation(s)
- Parashar Thapa
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai'i, Honolulu, HI 96822, USA
| | - Michael J Espiritu
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai'i, Honolulu, HI 96822, USA
| | - Chino C Cabalteja
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai'i, Honolulu, HI 96822, 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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15
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Lu A, Yang L, Xu S, Wang C. Various conotoxin diversifications revealed by a venomic study of Conus flavidus. Mol Cell Proteomics 2013; 13:105-18. [PMID: 24126141 DOI: 10.1074/mcp.m113.028647] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Conotoxins are peptide neurotoxins produced by predatory cone snails. They are mostly cysteine-rich short peptides with remarkable structural diversity. The conserved signal peptide sequences of their mRNA-encoded precursors have enabled the grouping of known conotoxins into a limited number of superfamilies. However, the conotoxins within each superfamily often present variable sequences, cysteine frameworks, and post-translational modifications. To understand better how conotoxins are diversified, we performed a venomic study with C. flavidus, an uninvestigated vermivorous Conus species, by combining transcriptomic and proteomic analyses. In order to obtain the full-length conotoxin sequences, protease digestion was not performed with the venom extraction prior to spectra acquisition via tandem mass spectrometry (MS/MS). Because conotoxins are produced from mRNA-encoded precursors by means of proteolytic cleavage, nonspecific digestion of precursors was applied during the database search. Special attention was also paid in interpreting the MS/MS spectra. All together, these analyses identified 69 nonredundant cDNA sequences and 31 conotoxin components with confident MS/MS spectra. A new Q-superfamily was also identified. More importantly, this study revealed that conotoxin-encoding transcripts are diversified by hypermutation, fragment insertion/deletion, and mutation-induced premature termination, and that a single mRNA species can produce multiple toxin products through alternative post-translational modifications and alternative cleavages of the translated precursor. These multiple diversification strategies at different levels may explain, at least in part, the diversity of conotoxins, and provide the basis for further investigation.
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Affiliation(s)
- Aiping Lu
- Institute of Protein Research, School of Life Sciences and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, China
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16
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Aguilar MB, Zugasti-Cruz A, Falcón A, Batista CVF, Olivera BM, de la Cotera EPH. A novel arrangement of Cys residues in a paralytic peptide of Conus cancellatus (jr. syn.: Conus austini), a worm-hunting snail from the Gulf of Mexico. Peptides 2013; 41:38-44. [PMID: 23474143 PMCID: PMC3677226 DOI: 10.1016/j.peptides.2013.02.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Revised: 02/05/2013] [Accepted: 02/05/2013] [Indexed: 12/01/2022]
Abstract
The present study details the purification, the amino acid sequence determination, and a preliminary characterization of the biological effects in mice of a new conotoxin from the venom of Conus cancellatus (jr. syn.: Conus austini), a worm-hunting cone snail collected in the western Gulf of Mexico (Mexico). The 23-amino acid peptide, called as25a, is characterized by the sequence pattern CX1CX2CX8CX1CCX5, which is, for conotoxins, a new arrangement of six cysteines (framework XXV) that form three disulfide bridges. The primary structure (CKCPSCNFNDVTENCKCCIFRQP*; *, amidated C-terminus; calculated monoisotopic mass, 2644.09Da) was established by automated Edman degradation after reduction and alkylation, and MALDI-TOF and ESI mass spectrometry (monoisotopic mass, 2644.12/2644.08Da). Upon intracranial injection in mice, the purified peptide provokes paralysis of the hind limbs and death with a dose of 240 pmol (~0.635 μg, ~24.9 ng/g). In addition, a post-translational variant of this peptide (as25b) was identified and determined to contain two hydroxyproline residues. These peptides may represent a novel conotoxin gene superfamily.
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Affiliation(s)
- Manuel B Aguilar
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus Juriquilla, Querétaro 76230, Mexico.
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17
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Liu Z, Yu Z, Liu N, Zhao C, Hu J, Dai Q. cDNA cloning of conotoxins with framework XII from several Conus species. Acta Biochim Biophys Sin (Shanghai) 2010; 42:656-61. [PMID: 20732855 DOI: 10.1093/abbs/gmq066] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In our efforts for cloning novel I(2)-superfamily conotoxins using the signal peptide sequence, we identified a novel conotoxin Lt12.4 from Conus litteratus. This gene has a framework XII (-C-C-C-C-CC-C-C-), which is distinct from the cysteine pattern I(2)-superfamily conotoxin (-C-C-CC-CC-C-C-). Subsequently, we found the signal peptide sequence of Lt12.4 by 5'-RACE. Using this new sequence, we identified another five novel conotoxins with this cysteine pattern from four Conus species (Conus eburneus, Conus imperialis, Conus marmoreus, and C. litteratus). These novel conotoxins have the same cysteine pattern as the reported Gla-TxX and Gla-MII, and may contain Gla residues. Furthermore, they have the highly conserved signal peptide and hypervariable mature peptide sequences, and widely exist in Conus species. Therefore, it could be defined as a new superfamily of E-conotoxins.
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Affiliation(s)
- Zhuguo Liu
- Beijing Institute of Biotechnology, China
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18
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Kaas Q, Westermann JC, Craik DJ. Conopeptide characterization and classifications: an analysis using ConoServer. Toxicon 2010; 55:1491-509. [PMID: 20211197 DOI: 10.1016/j.toxicon.2010.03.002] [Citation(s) in RCA: 160] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Revised: 02/25/2010] [Accepted: 03/01/2010] [Indexed: 10/19/2022]
Abstract
Cone snails are carnivorous marine gastropods that have evolved potent venoms to capture their prey. These venoms comprise a rich and diverse cocktail of peptide toxins, or conopeptides, whose high diversity has arisen from an efficient hypermutation mechanism, combined with a high frequency of post-translational modifications. Conopeptides bind with high specificity to distinct membrane receptors, ion channels, and transporters of the central and muscular nervous system. As well as serving their natural function in prey capture, conopeptides have been utilized as versatile tools in neuroscience and have proven valuable as drug leads that target the nervous system in humans. This paper examines current knowledge on conopeptide sequences based on an analysis of gene and peptide sequences in ConoServer (http://www.conoserver.org), a specialized database of conopeptide sequences and three-dimensional structures. We describe updates to the content and organization of ConoServer and discuss correlations between gene superfamilies, cysteine frameworks, pharmacological families targeted by conopeptides, and the phylogeny, habitat, and diet of cone snails. The study identifies gaps in current knowledge of conopeptides and points to potential directions for future research.
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Affiliation(s)
- Quentin Kaas
- The University of Queensland, Institute for Molecular Bioscience, Division of Chemistry and Structural Biology, Brisbane, 4072 QLD, Australia
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19
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Bingham JP, Mitsunaga E, Bergeron ZL. Drugs from slugs--past, present and future perspectives of omega-conotoxin research. Chem Biol Interact 2010; 183:1-18. [PMID: 19800874 DOI: 10.1016/j.cbi.2009.09.021] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2009] [Revised: 09/03/2009] [Accepted: 09/24/2009] [Indexed: 12/18/2022]
Abstract
Peptides from the venom of carnivorous cone shells have provided six decades of intense research, which has led to the discovery and development of novel analgesic peptide therapeutics. Our understanding of this unique natural marine resource is however somewhat limited. Given the past pharmacological record, future investigations into the toxinology of these highly venomous tropical marine snails will undoubtedly yield other highly selective ion channel inhibitors and modulators. With over a thousand conotoxin-derived sequences identified to date, those identified as ion channel inhibitors represent only a small fraction of the total. Here we discuss our present understanding of conotoxins, focusing on the omega-conotoxin peptide family, and illustrate how such a seemingly simple snail has yielded a highly effective clinical drug.
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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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20
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Aguilar MB, Flores-Torres A, Batista CVF, Falcón A, López-Vera E, de la Cotera EPH. Structural characterization of five post-translationally modified isomorphs of a novel putative delta-conotoxin from the vermivorous snail Conus delessertii from the Mexican Caribbean Sea. Peptides 2009; 30:458-66. [PMID: 19118590 DOI: 10.1016/j.peptides.2008.12.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2008] [Revised: 12/01/2008] [Accepted: 12/01/2008] [Indexed: 11/22/2022]
Abstract
A novel peptide, de7b, was isolated from the venom of Conus delessertii, a worm-hunting species collected in the Caribbean Sea off the Yucatan Peninsula. Its primary structure was determined by automated Edman degradation and confirmed by mass spectrometry: it contains 28 amino acids, including six Cys residues. Peptide de7b is the second, O-conotoxin-like peptide isolated from the venom of this species, and it exists in different post-translationally modified isomorphs, some of which contain gamma-carboxy-glutamate (gamma) and/or 4-hydroxy-proline (O) at positions 4, 7, and/or 14. Its primary structure is DCI(P/O)GG(E/gamma)NCDVFR(O/P)YRCCSGYCILLLCA, with molecular masses varying from 3078.6 to 3154.6Da, depending on the number and kind of modified amino acid residues. Peptide de7b shows significant sequence identity with several O-conotoxins purified and biologically characterized from molluscivorous and piscivorous cone snails of the Indo-Pacific region, the tropical Atlantic and Eastern Pacific Oceans, especially with the delta-conotoxins but also with the omega-conotoxins from molluscivorous species, which suggests that it might affect voltage-gated Na(+) or Ca(2+)channels. Peptide de7b has 32% sequence identity with putative gamma-conotoxin de7a, previously characterized from the same species; both peptides contain the same number of amino acid residues and of non-Cys residues between the pairs of consecutive Cys residues. However, these peptides have charge differences at seven positions within the N-terminal half indicating that they might have distinct molecular targets that remain to be identified.
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Affiliation(s)
- Manuel B Aguilar
- 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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21
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King GF, Gentz MC, Escoubas P, Nicholson GM. A rational nomenclature for naming peptide toxins from spiders and other venomous animals. Toxicon 2008; 52:264-76. [DOI: 10.1016/j.toxicon.2008.05.020] [Citation(s) in RCA: 230] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2008] [Revised: 05/23/2008] [Accepted: 05/23/2008] [Indexed: 11/25/2022]
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22
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Wallin R, Wajih N, Hutson SM. VKORC1: A Warfarin‐Sensitive Enzyme in Vitamin K Metabolism and Biosynthesis of Vitamin K‐Dependent Blood Coagulation Factors. VITAMINS & HORMONES 2008; 78:227-46. [DOI: 10.1016/s0083-6729(07)00011-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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23
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Bandyopadhyay PK. Vitamin K-dependent gamma-glutamylcarboxylation: an ancient posttranslational modification. VITAMINS AND HORMONES 2008; 78:157-84. [PMID: 18374194 DOI: 10.1016/s0083-6729(07)00008-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The vitamin K-dependent carboxylase carries out the posttranslational modification of specific glutamate residues in proteins to gamma-carboxy glutamic acid (Gla) in the presence of reduced vitamin K, molecular oxygen, and carbon dioxide. In the process, reduced vitamin K is converted to vitamin K epoxide, which is subsequently reduced to vitamin K, by vitamin K epoxide reductase (VKOR) for use in the carboxylation reaction. The modification has a wide range of physiological implications, including hemostasis, bone calcification, and signal transduction. The enzyme interacts with a high affinity gamma-carboxylation recognition sequence (gamma-CRS) of the substrate and carries out multiple modifications of the substrate before the product is released. This mechanism ensures complete carboxylation of the Gla domain of the coagulation factors, which is essential for their biological activity. gamma-Carboxylation, originally discovered in mammals, is widely distributed in the animal kingdom. It has been characterized in sea squirt (Ciona intestinalis), in flies (Drosophila melanogaster), and in marine snails (Conus textile), none of which have a blood coagulation system similar to mammals. The cone snails express a large array of gamma-carboxylated peptides that modulate the activity of ion channels. These findings have led to the suggestion that gamma-carboxylation is an extracellular posttranslational modification that antedates the divergence of molluscs, arthropods, and chordates. I will first summarize recent understanding of gamma-carboxylase and gamma-carboxylation gleaned from experiments using the mammalian enzyme, and then I will briefly describe the available information on gamma-carboxylation in D. melanogaster and C. textile.
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Affiliation(s)
- Pradip K Bandyopadhyay
- Department of Biology, University of Utah, 257 South 1400 East, Salt Lake City, Utah 84112, USA
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24
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Luna-Ramírez KS, Aguilar MB, Falcón A, Heimer de la Cotera EP, Olivera BM, Maillo M. An O-conotoxin from the vermivorous Conus spurius active on mice and mollusks. Peptides 2007; 28:24-30. [PMID: 17166626 DOI: 10.1016/j.peptides.2006.08.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2006] [Revised: 08/22/2006] [Accepted: 08/22/2006] [Indexed: 11/30/2022]
Abstract
Here, we report the purification, amino acid sequence and a preliminary biological characterization of a peptide, sr7a, from the venom of Conus spurius, a vermivorous species collected in the Yucatan Channel, Mexico. The peptide consists of 32 amino acid residues (CLQFGSTCFLGDDDICCSGECFYSGGTFGICS&; &, amidated C-terminus) and contains six cysteines arranged in the pattern (C-C-CC-C-C) that characterizes the O-superfamily of conotoxins. This superfamily includes several pharmacological families (omega-, kappa-, muO-, delta- and gamma-conotoxins) that target Ca(2+), K(+), Na(+) and pacemaker voltage-gated ion channels. Compared with other O-conotoxins that were purified from venoms, this peptide displays sequence similarity with omega-SVIA (from Conus striatus), delta-TxVIA/B (from Conus textile), omega-CVID (from Conus catus) and kappa-PVIIA (from Conus purpurascens). At a dose of 250 pmol, peptide sr7a elicited hyperactivity when injected intracranially into mice and produced paralysis when injected into the pedal muscle of freshwater snails, Pomacea paludosa, but it had no apparent effect after intramuscular injection into the limpet Patella opea or the freshwater fish Lebistes reticulatus.
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Affiliation(s)
- Karen S Luna-Ramírez
- Laboratorio de Neurofarmacología Marina, Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus Juriquilla, Querétaro 76230, México
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25
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Czerwiec E, Kalume DE, Roepstorff P, Hambe B, Furie B, Furie BC, Stenflo J. Novel gamma-carboxyglutamic acid-containing peptides from the venom of Conus textile. FEBS J 2006; 273:2779-88. [PMID: 16817904 DOI: 10.1111/j.1742-4658.2006.05294.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The cone snail is the only invertebrate system in which the vitamin K-dependent carboxylase (or gamma-carboxylase) and its product gamma-carboxyglutamic acid (Gla) have been identified. It remains the sole source of structural information of invertebrate gamma-carboxylase substrates. Four novel Gla-containing peptides were purified from the venom of Conus textile and characterized using biochemical methods and mass spectrometry. The peptides Gla(1)-TxVI, Gla(2)-TxVI/A, Gla(2)-TxVI/B and Gla(3)-TxVI each have six Cys residues and belong to the O-superfamily of conotoxins. All four conopeptides contain 4-trans-hydroxyproline and the unusual amino acid 6-l-bromotryptophan. Gla(2)-TxVI/A and Gla(2)-TxVI/B are isoforms with an amidated C-terminus that differ at positions +1 and +13. Three isoforms of Gla(3)-TxVI were observed that differ at position +7: Gla(3)-TxVI, Glu7-Gla(3)-TxVI and Asp7-Gla(3)-TxVI. The cDNAs encoding the precursors of the four peptides were cloned. The predicted signal sequences (amino acids -46 to -27) were nearly identical and highly hydrophobic. The predicted propeptide region (-20 to -1) that contains the gamma-carboxylation recognition site (gamma-CRS) is very similar in Gla(2)-TxVI/A, Gla(2)-TxVI/B and Gla(3)-TxVI, but is more divergent for Gla(1)-TxVI. Kinetic studies utilizing the Conusgamma-carboxylase and synthetic peptide substrates localized the gamma-CRS of Gla(1)-TxVI to the region -14 to -1 of the polypeptide precursor: the Km was reduced from 1.8 mm for Gla (1)-TxVI lacking a propeptide to 24 microm when a 14-residue propeptide was attached to the substrate. Similarly, addition of an 18-residue propeptide to Gla(2)-TxVI/B reduced the Km value tenfold.
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Affiliation(s)
- Eva Czerwiec
- Marine Biological Laboratory, Woods Hole, MA, USA.
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26
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Abstract
In the four decades since toxinologists in Australia and elsewhere started to investigate the active constituents of venomous cone snails, a wealth of information has emerged on the various classes of peptides and proteins that make their venoms such potent bioactive cocktails. This article provides an overview of the current state of knowledge of these venom constituents, several of which are of interest as potential human therapeutics as a consequence of their high potency and exquisite target specificity. With the promise of as many as 50,000 venom components across the entire Conus genus, many more interesting peptides can be anticipated.
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Affiliation(s)
- Raymond S Norton
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville 3050, Victoria, Australia.
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27
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Zugasti-Cruz A, Maillo M, López-Vera E, Falcón A, Heimer de la Cotera EP, Olivera BM, Aguilar MB. Amino acid sequence and biological activity of a gamma-conotoxin-like peptide from the worm-hunting snail Conus austini. Peptides 2006; 27:506-11. [PMID: 16325964 DOI: 10.1016/j.peptides.2005.07.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2005] [Accepted: 07/20/2005] [Indexed: 11/19/2022]
Abstract
A novel 31-residue toxin, named as7a, was isolated and characterized from the venom of Conus austini, a vermivorous cone snail collected in the western Gulf of Mexico. The complete amino acid sequence, TCKQKGEGCSLDVgammaCCSSSCKPGGPLFDFDC, was determined by automatic Edman sequencing after reduction and alkylation. The sequence shows six Cys residues arranged in the pattern that defines the O-superfamily of conotoxins, and the sequence motif -gammaCCS-, which has only been found in the gamma-conotoxin family. The molecular mass of the native peptide was determined by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry, which confirmed the chemical analyses and suggested a free C-terminus. The purified peptide elicited toxic effects in the freshwater snail Pomacea paludosa after intramuscular injection, but it had no effect when injected intracerebrally into mice. The structural similarity of peptide as7a to other gamma-conotoxins suggests that modulation of pacemaker channels could be responsible for its biological activity.
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Affiliation(s)
- Alejandro Zugasti-Cruz
- Posgrado en Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Ciudad Universitaria, México D.F. 04510, Mexico
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28
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Jones RM, Cartier GE, McIntosh JM, Bulaj G, Farrar VE, Olivera BM. Composition and therapeutic utility of conotoxins from genus Conus. Patent status 1996 - 2000. Expert Opin Ther Pat 2005. [DOI: 10.1517/13543776.11.4.603] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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29
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Aguilar MB, López-Vera E, Imperial JS, Falcón A, Olivera BM, de la Cotera EPH. Putative gamma-conotoxins in vermivorous cone snails: the case of Conus delessertii. Peptides 2005; 26:23-7. [PMID: 15626501 DOI: 10.1016/j.peptides.2004.10.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Peptide de7a was purified from the venom of Conus delessertii, a vermivorous cone snail collected in the Yucatan Channel, Mexico. Its amino acid sequence was determined by automatic Edman degradation after reduction and alkylation. The sequence shows six Cys residues arranged in the pattern that defines the O-superfamily of conotoxins, and several post-translationally modified residues. The determination of its molecular mass by means of laser desorption ionization time-of-flight mass spectrometry (average mass, 3170.0 Da) confirmed the chemical data and suggested amidation of the C-terminus. The primary structure (ACKOKNNLCAITgammaMAgammaCCSGFCLIYRCS*; O, hydroxyproline; gamma, gamma-carboxyglutamate; *, amidated C-terminus; calculated average mass, 3169.66 Da) of de7a contains a motif (gammaCCS) that has previously only been found in two other toxins, both from molluscivorous cone snails: TxVIIA from Conus textile and gamma-PnVIIA from Conus pennaceus. These toxins cause depolarization and increased firing of action potentials in molluscan neuronal systems, and toxin gamma-PnVIIA has been shown to act as an agonist of neuronal pacemaker cation currents. The similarities to toxins TxVIIA and gamma-PnVIIA suggest that peptide de7a might also affect voltage-gated nonspecific cation pacemaker channels.
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Affiliation(s)
- Manuel B Aguilar
- Laboratory of Marine Neuropharmacology, Institute of Neurobiology, Universidad Nacional Autónoma de México, Juriquilla, Qro. 76230, México.
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30
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Hansson K, Ma X, Eliasson L, Czerwiec E, Furie B, Furie BC, Rorsman P, Stenflo J. The First γ-Carboxyglutamic Acid-containing Contryphan. J Biol Chem 2004; 279:32453-63. [PMID: 15155730 DOI: 10.1074/jbc.m313825200] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Contryphans constitute a group of conopeptides that are known to contain an unusual density of post-translational modifications including tryptophan bromination, amidation of the C-terminal residue, leucine, and tryptophan isomerization, and proline hydroxylation. Here we report the identification and characterization of a new member of this family, glacontryphan-M from the venom of Conus marmoreus. This is the first known example of a contryphan peptide carrying glutamyl residues that have been post-translationally carboxylated to gamma-carboxyglutamyl (Gla) residues. The amino acid sequence of glacontryphan-M was determined using automated Edman degradation and electrospray ionization mass spectrometry. The amino acid sequence of the peptide is: Asn-Gla-Ser-Gla-Cys-Pro-D-Trp-His-Pro-Trp-Cys. As with most other contryphans, glacontryphan-M is amidated at the C terminus and maintains the five-residue intercysteine loop. The occurrence of a D-tryptophan residue was confirmed by chemical synthesis and HPLC elution profiles. Using fluorescence spectroscopy we demonstrated that the Gla-containing peptide binds calcium with a K(D) of 0.63 mM. Cloning of the full-length cDNA encoding glacontryphan-M revealed that the primary translation product carries an N-terminal signal/propeptide sequence that is homologous to earlier reported contryphan signal/propeptide sequences up to 10 amino acids preceding the toxin region. Electrophysiological experiments, carried out on mouse pancreatic B-cells, showed that glacontryphan-M blocks L-type voltage-gated calcium ion channel activity in a calcium-dependent manner. Glacontryphan-M is the first contryphan reported to modulate the activity of L-type calcium ion channels.
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MESH Headings
- 1-Carboxyglutamic Acid/metabolism
- Amino Acid Sequence
- Animals
- Base Sequence
- Calcium/chemistry
- Calcium/metabolism
- Calcium Channels/metabolism
- Cations
- Chromatography, High Pressure Liquid
- DNA, Complementary/metabolism
- Disulfides
- Dose-Response Relationship, Drug
- Electrophysiology
- Hydrolysis
- Ions
- Kinetics
- Molecular Sequence Data
- Mollusk Venoms/chemistry
- Mollusk Venoms/metabolism
- Peptide Biosynthesis
- Peptides/chemistry
- Peptides, Cyclic/chemistry
- Peptides, Cyclic/metabolism
- Protein Binding
- Protein Processing, Post-Translational
- Protein Structure, Tertiary
- Sequence Homology, Amino Acid
- Snails
- Spectrometry, Fluorescence
- Spectrometry, Mass, Electrospray Ionization
- Time Factors
- Tryptophan/chemistry
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Affiliation(s)
- Karin Hansson
- Department of Clinical Chemistry, Lund University, University Hospital, Malmö, S-205 02 Malmo, Sweden.
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31
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Hansson K, Furie B, Furie BC, Stenflo J. Isolation and characterization of three novel Gla-containing Conus marmoreus venom peptides, one with a novel cysteine pattern. Biochem Biophys Res Commun 2004; 319:1081-7. [PMID: 15194478 DOI: 10.1016/j.bbrc.2004.05.088] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2004] [Indexed: 11/24/2022]
Abstract
One defining characteristic of Conus venom peptides is the high frequency of posttranslational modifications found. We report the discovery and initial characterization of three novel gamma-carboxyglutamic acid (Gla)-containing conotoxins, Gla-MrII, Gla-MrIII, and Gla-MrIV, isolated from the venom of the mollusc-hunting cone snail Conus marmoreus. Peptide Gla-MrII, a 50 amino acid residue peptide, carries eight cysteine residues arranged in a novel cysteine pattern, and five gamma-carboxyglutamic acid residues. The monoisotopic molecular mass was determined by electrospray ionization mass spectrometry to 5860.23 Da, consistent with the peptide having the cysteine residues disulphide-bonded and having a free acid C-terminus. Peptides Gla-MrIII and Gla-MrIV each contain two gamma-carboxyglutamic acid residues and share little sequence similarity to previously identified conotoxins. Both peptides contain four cysteine residues that are positioned in the linear sequence in a manner reminiscent of conotoxins belonging to cysteine scaffold superfamily T (scaffold T-1). Determination of the monoisotopic molecular masses revealed that Gla-MrIII is amidated at its C-terminus while Gla-MrIV has a free C-terminal acid.
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Affiliation(s)
- Karin Hansson
- Department of Clinical Chemistry, Lund University, University Hospital, Malmö, S-20502 Malmö, Sweden.
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32
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Abstract
The cone snails (genus Conus) are venomous marine molluscs that use small, structured peptide toxins (conotoxins) for prey capture, defense, and competitor deterrence. Each of the 500 Conus can express approximately 100 different conotoxins, with little overlap between species. An overwhelming majority of these peptides are probably targeted selectively to a specific ion channel. Because conotoxins discriminate between closely related subtypes of ion channels, they are widely used as pharmacological agents in ion channel research, and several have direct diagnostic and therapeutic potential. Large conotoxin families can comprise hundreds or thousands of different peptides; most families have a corresponding ion channel family target (i.e., omega-conotoxins and Ca channels, alpha-conotoxins and nicotinic receptors). Different conotoxin families may have different ligand binding sites on the same ion channel target (i.e., mu-conotoxins and delta-conotoxins to sites 1 and 6 of Na channels, respectively). The individual peptides in a conotoxin family are typically each selectively targeted to a diverse set of different molecular isoforms within the same ion channel family. This review focuses on the targeting specificity of conotoxins and their differential binding to different states of an ion channel.
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Affiliation(s)
- Heinrich Terlau
- AG Molekulare und Zelluläre Neuropharmakologie, Max-Planck-Institut für Experimentelle Medizin, Göttingen, Germany
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33
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Czerwiec E, Begley GS, Bronstein M, Stenflo J, Taylor K, Furie BC, Furie B. Expression and characterization of recombinant vitamin K-dependent gamma-glutamyl carboxylase from an invertebrate, Conus textile. EUROPEAN JOURNAL OF BIOCHEMISTRY 2002; 269:6162-72. [PMID: 12473112 DOI: 10.1046/j.1432-1033.2002.03335.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The marine snail Conus is the sole invertebrate wherein both the vitamin K-dependent carboxylase and its product, gamma-carboxyglutamic acid, have been identified. To examine its biosynthesis of gamma-carboxyglutamic acid, we studied the carboxylase from Conus venom ducts. The carboxylase cDNA from Conus textile has an ORF that encodes a 811-amino-acid protein which exhibits sequence similarity to the vertebrate carboxylases, with 41% identity and approximately 60% sequence similarity to the bovine carboxylase. Expression of this cDNA in COS cells or insect cells yielded vitamin K-dependent carboxylase activity and vitamin K-dependent epoxidase activity. The recombinant carboxylase has a molecular mass of approximately 130 kDa. The recombinant Conus carboxylase carboxylated Phe-Leu-Glu-Glu-Leu and the 28-residue peptides based on residues -18 to +10 of human proprothrombin and proFactor IX with Km values of 420 micro m, 1.7 micro m and 6 micro m, respectively; the Km for vitamin K is 52 micro m. The Km values for peptides based on the sequence of the conotoxin epsilon-TxIX and two precursor analogs containing 12 or 29 amino acids of the propeptide region are 565 micro m, 75 micro m and 74 micro m, respectively. The recombinant Conus carboxylase, in the absence of endogenous substrates, is stimulated up to fivefold by vertebrate propeptides but not by Conus propeptides. These results suggest two propeptide-binding sites in the carboxylase, one that binds the Conus and vertebrate propeptides and is required for substrate binding, and the other that binds only the vertebrate propeptide and is required for enzyme stimulation. The marked functional and structural similarities between the Conus carboxylase and vertebrate vitamin K-dependent gamma-carboxylases argue for conservation of a vitamin K-dependent carboxylase across animal species and the importance of gamma-carboxyglutamic acid synthesis in diverse biological systems.
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Affiliation(s)
- Eva Czerwiec
- Marine Biological Laboratory, Woods Hole, MA, USA
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34
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Blandl T, Zajicek J, Prorok M, Castellino FJ. Sequence requirements for the N-methyl-D-aspartate receptor antagonist activity of conantokin-R. J Biol Chem 2001; 276:7391-6. [PMID: 11096077 DOI: 10.1074/jbc.m006648200] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Conantokin-R (con-R), a gamma-carboxyglutamate-containing 27-residue peptide, is a natural peptide inhibitor of the N-methyl-d-aspartate (NMDA) subtype glutamate receptor. Synthetic analogs of con-R were generated to evaluate the importance of the individual structural elements of this peptide in its NMDA receptor antagonist activity, measured by inhibition of the spermine-enhanced binding of the NMDA receptor-specific channel blocker, [(3)H]MK-801, to rat brain membranes. Progressive C-terminal truncations of the 27-residue peptide revealed stages of severe activity loss. These occurred at con-R[1-11] and con-R[1-7], corresponding to the deletions of Leu(12)-Pro(27) and Met(8)-Pro(27) respectively. A second set of analogs featured single Ala substitutions in the fully active con-R[1-17] fragment. The replacement of Met(8) and Leu(12) by Ala resulted in approximate 20- and 55-fold decreases of inhibitor potency, respectively. In addition to these two residues, the only other positions where a single Ala substitution led to substantial losses (from 11-fold to >1000-fold) of activity were those of the first five N-terminal amino acids. Based on the above findings, the binding epitope of con-R was localized to the N-terminal turn of the helix and other residues on one face along two subsequent turns. This contribution pattern of the side chains in activity closely resembles the results obtained with another member of this peptide family, conantokin-T. The secondary structure and metal ion binding properties of the con-R variants were also evaluated using circular dichroism spectroscopy. Divalent cation-dependent increases of alpha-helix content were observed in most analogs. However, analogs with replacement of Gla(11) and Gla(15), as well as truncation fragments shorter than 15 residues, lost the ability to be stabilized by metal ions. These results confirmed the location of the primary divalent cation binding locus at Gla(11) and Gla(15). Additional interactions were indicated by the reduced alpha-helix stability in the Ala analogs of Gla(4), Lys(7), and Arg(14).
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Affiliation(s)
- T Blandl
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
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35
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Metzler DE, Metzler CM, Sauke DJ. Chemical Communication Between Cells. Biochemistry 2001. [DOI: 10.1016/b978-012492543-4/50033-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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36
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Hill JM, Atkins AR, Loughnan ML, Jones A, Adams DA, Martin RC, Lewis RJ, Craik DJ, Alewood PF. Conotoxin TVIIA, a novel peptide from the venom of Conus tulipa 1. Isolation, characterization and chemical synthesis. EUROPEAN JOURNAL OF BIOCHEMISTRY 2000; 267:4642-8. [PMID: 10903496 DOI: 10.1046/j.1432-1327.2000.01508.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A novel conotoxin belonging to the 'four-loop' structural class has been isolated from the venom of the piscivorous cone snail Conus tulipa. It was identified using a chemical-directed strategy based largely on mass spectrometric techniques. The new toxin, conotoxin TVIIA, consists of 30 amino-acid residues and contains three disulfide bonds. The amino-acid sequence was determined by Edman analysis as SCSGRDSRCOOVCCMGLMCSRGKCVSIYGE where O = 4-transL-hydroxyproline. Two under-hydroxylated analogues, [Pro10]TVIIA and [Pro10,11]TVIIA, were also identified in the venom of C. tulipa. The sequences of TVIIA and [Pro10]TVIIA were further verified by chemical synthesis and coelution studies with native material. Conotoxin TVIIA has a six cysteine/four-loop structural framework common to many peptides from Conus venoms including the omega-, delta- and kappa-conotoxins. However, TVIIA displays little sequence homology with these well-characterized pharmacological classes of peptides, but displays striking sequence homology with conotoxin GS, a peptide from Conus geographus that blocks skeletal muscle sodium channels. These new toxins and GS share several biochemical features and represent a distinct subgroup of the four-loop conotoxins.
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Affiliation(s)
- J M Hill
- Centre for Drug Design and Development, The Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
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37
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Blandl T, Warder SE, Prorok M, Castellino FJ. Structure-function relationships of the NMDA receptor antagonist peptide, conantokin-R. FEBS Lett 2000; 470:139-46. [PMID: 10734223 DOI: 10.1016/s0014-5793(00)01309-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Conantokin-R (con-R) is a gamma-carboxyglutamate-containing 27-residue neuroactive peptide present in the venom of Conus radiatus, and acts as a non-competitive antagonist of the N-methyl-D-aspartate (NMDA) receptor. This peptide features a single disulfide bond, a type of structural element found in most classes of conotoxins, but not in other conantokins. The NMDA receptor antagonist activity of chemically synthesized con-R was determined through an assay involving inhibition of the spermine-enhanced binding of the NMDA receptor channel blocker, [(3)H]MK-801, to rat brain membranes, and yielded an IC(50) of 93 nM. This value represents a 2-5 times better potency than con-G or con-T, the other two characterized conantokins. Circular dichroism (CD) analysis of the metal-free form of con-R is indicative of a low alpha-helical content. There is an increase in alpha-helicity upon the addition of divalent cations, such as Ca(2+), Mg(2+), or Zn(2+). Isothermal titration calorimetry experiments showed one detectable Mg(2+) binding site with a K(d) of 6.5 microM, and two binding sites for Zn(2+), with K(d) values of 150 nM and 170 microM. Residue-specific information of the conformational state of con-R was obtained by two-dimensional (1)H-NMR. Analyses of the alpha-proton chemical shifts, NOE patterns, and hydrogen exchange rates of the peptide indicated an alpha-helical conformation for residues 1-19. Synthetic con-R-derived peptide variants, containing deletions of 7 and 10 amino acid residues from the carboxy-terminus of the wild-type peptide, displayed unaltered cation binding and NMDA receptor antagonist properties. The alpha-helical secondary structures of the two truncation peptides were more stable than full-length con-R, as evidenced by CD measurements and reduced backbone hydrogen exchange rates. These results provide experimental evidence that the structural elements common to the three conantokins thus far identified are the primary determinants for receptor function and cation binding/secondary structure stability.
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Affiliation(s)
- T Blandl
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
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38
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Kalume DE, Stenflo J, Czerwiec E, Hambe B, Furie BC, Furie B, Roepstorff P. Structure determination of two conotoxins from Conus textile by a combination of matrix-assisted laser desorption/ionization time-of-flight and electrospray ionization mass spectrometry and biochemical methods. JOURNAL OF MASS SPECTROMETRY : JMS 2000; 35:145-156. [PMID: 10679974 DOI: 10.1002/(sici)1096-9888(200002)35:2<145::aid-jms922>3.0.co;2-i] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Two highly modified conotoxins from the mollusc Conus textile, epsilon-TxIX and Gla(1)-TxVI, were characterized by matrix-assisted laser desorption/ionization and electrospray mass spectrometry and also by electrospray ionization tandem and triple mass spectrometry in combination with enzymatic cleavage and chemical modification reactions. The mass spectrometric studies allowed the confirmation of the sequence determined by Edman degradation and assignment of unidentified amino acid residues, among which bromotryptophan residues and an O-glycosylated threonine residue were observed. Methyl esterification was found necessary for the site-specific assignment of the Gla residues in the peptides.
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Affiliation(s)
- D E Kalume
- Department of Molecular Biology, University of Southern Denmark, Odense University, Campusvej 55, DK-5230 Odense M, Denmark
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39
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Wolfender JL, Chu F, Ball H, Wolfender F, Fainzilber M, Baldwin MA, Burlingame AL. Identification of tyrosine sulfation in Conus pennaceus conotoxins alpha-PnIA and alpha-PnIB: further investigation of labile sulfo- and phosphopeptides by electrospray, matrix-assisted laser desorption/ionization (MALDI) and atmospheric pressure MALDI mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 1999; 34:447-454. [PMID: 10226369 DOI: 10.1002/(sici)1096-9888(199904)34:4<447::aid-jms801>3.0.co;2-1] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Liquid chromatography/electrospray ionization mass spectrometry was used to investigate the peptide composition of the venom of Conus pennaceus, a molluscivorous cone shell from the Red Sea. Based on observed M(r)s, this venom contained all known conotoxins previously isolated and identified from this species. Interestingly, the doubly protonated species of only two of these conotoxins, alpha-PnIA and alpha-PnIB, showed additional related ions at +40 m/z (+80 Da), indicating the presence of either sulfation or phosphorylation in both components. High-performance liquid chromatographic (HPLC) fractions containing these two conotoxins were examined by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry in both positive and negative ion modes, as well as by MALDI high-energy collision-induced dissociation. These experiments established the presence of a single sulfated tyrosine residue within both alpha-PnIA and alpha-PnIB. Hence their post-translationally modified sequences are GCCSLPPCAANNPDY(S)C-NH2 (alpha-PnIA) and GCCSLPPCALSNPDY(S)C-NH2 (alpha-PnIB). This assignment was supported by comparison of their mass spectral behavior with that of known sulfated and phosphorylated peptides. This data clarified further the distinguishing features of the ionization and fragmentation of such modified peptides. Selective disulfide folding of synthetic alpha-PnIB demonstrated that both sulfated and non-sulfated toxins co-elute on reversed-phase HPLC and that alpha-PnIB possesses the same disulfide connectivity as other 'classical' alpha-conotoxins reported previously.
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Affiliation(s)
- J L Wolfender
- Department of Pharmaceutical Chemistry, University of California, San Francisco 94143-0446, USA
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40
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Affiliation(s)
- A L Burlingame
- Department of Pharmaceutical Chemistry, University of California, San Francisco 94143-0446, USA
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