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Baker JG, Summers RJ. Adrenoceptors: Receptors, Ligands and Their Clinical Uses, Molecular Pharmacology and Assays. Handb Exp Pharmacol 2024. [PMID: 38926158 DOI: 10.1007/164_2024_713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2024]
Abstract
The nine G protein-coupled adrenoceptor subtypes are where the endogenous catecholamines adrenaline and noradrenaline interact with cells. Since they are important therapeutic targets, over a century of effort has been put into developing drugs that modify their activity. This chapter provides an outline of how we have arrived at current knowledge of the receptors, their physiological roles and the methods used to develop ligands. Initial studies in vivo and in vitro with isolated organs and tissues progressed to cell-based techniques and the use of cloned adrenoceptor subtypes together with high-throughput assays that allow close examination of receptors and their signalling pathways. The crystal structures of many of the adrenoceptor subtypes have now been determined opening up new possibilities for drug development.
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Affiliation(s)
- Jillian G Baker
- Cell Signalling, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, UK.
- Department of Respiratory Medicine, Nottingham University Hospitals NHS Trust, Nottingham, UK.
| | - Roger J Summers
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia.
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2
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Lebedev AT, Vasileva ID, Samgina TY. FT-MS in the de novo top-down sequencing of natural nontryptic peptides. MASS SPECTROMETRY REVIEWS 2022; 41:284-313. [PMID: 33347655 DOI: 10.1002/mas.21678] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 11/25/2020] [Accepted: 11/25/2020] [Indexed: 06/12/2023]
Abstract
The present review covers available results on the application of FT-MS for the de novo sequencing of natural peptides of various animals: cones, bees, snakes, amphibians, scorpions, and so forth. As these peptides are usually bioactive, the animals efficiently use them as a weapon against microorganisms or higher animals including predators. These peptides represent definite interest as drugs of future generations since the mechanism of their activity is completely different in comparison with that of the modern antibiotics. Utilization of those peptides as antibiotics can eliminate the problem of the bacterial resistance development. Sequence elucidation of these bioactive peptides becomes even more challenging when the species genome is not available and little is known about the protein origin and other properties of those peptides in the study. De novo sequencing may be the only option to obtain sequence information. The benefits of FT-MS for the top-down peptide sequencing, the general approaches of the de novxxo sequencing, the difficult cases involving sequence coverage, isobaric and isomeric amino acids, cyclization of short peptides, the presence of posttranslational modifications will be discussed in the review.
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Affiliation(s)
- Albert T Lebedev
- Organic Chemistry Department, M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Irina D Vasileva
- Organic Chemistry Department, M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Tatiana Y Samgina
- Organic Chemistry Department, M.V. Lomonosov Moscow State University, Moscow, Russia
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3
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Van Baelen AC, Robin P, Kessler P, Maïga A, Gilles N, Servent D. Structural and Functional Diversity of Animal Toxins Interacting With GPCRs. Front Mol Biosci 2022; 9:811365. [PMID: 35198603 PMCID: PMC8859281 DOI: 10.3389/fmolb.2022.811365] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 01/05/2022] [Indexed: 12/12/2022] Open
Abstract
Peptide toxins from venoms have undergone a long evolutionary process allowing host defense or prey capture and making them highly selective and potent for their target. This has resulted in the emergence of a large panel of toxins from a wide diversity of species, with varied structures and multiple associated biological functions. In this way, animal toxins constitute an inexhaustible reservoir of druggable molecules due to their interesting pharmacological properties. One of the most interesting classes of therapeutic targets is the G-protein coupled receptors (GPCRs). GPCRs represent the largest family of membrane receptors in mammals with approximately 800 different members. They are involved in almost all biological functions and are the target of almost 30% of drugs currently on the market. Given the interest of GPCRs in the therapeutic field, the study of toxins that can interact with and modulate their activity with the purpose of drug development is of particular importance. The present review focuses on toxins targeting GPCRs, including peptide-interacting receptors or aminergic receptors, with a particular focus on structural aspects and, when relevant, on potential medical applications. The toxins described here exhibit a great diversity in size, from 10 to 80 amino acids long, in disulfide bridges, from none to five, and belong to a large panel of structural scaffolds. Particular toxin structures developed here include inhibitory cystine knot (ICK), three-finger fold, and Kunitz-type toxins. We summarize current knowledge on the structural and functional diversity of toxins interacting with GPCRs, concerning first the agonist-mimicking toxins that act as endogenous agonists targeting the corresponding receptor, and second the toxins that differ structurally from natural agonists and which display agonist, antagonist, or allosteric properties.
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Affiliation(s)
- Anne-Cécile Van Baelen
- CEA, Département Médicaments et Technologies pour La Santé (DMTS), SIMoS, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Philippe Robin
- CEA, Département Médicaments et Technologies pour La Santé (DMTS), SIMoS, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Pascal Kessler
- CEA, Département Médicaments et Technologies pour La Santé (DMTS), SIMoS, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Arhamatoulaye Maïga
- CEA, Département Médicaments et Technologies pour La Santé (DMTS), SIMoS, Université Paris-Saclay, Gif-sur-Yvette, France
- CHU Sainte Justine, Université de Montréal, Montreal, QC, Canada
| | - Nicolas Gilles
- CEA, Département Médicaments et Technologies pour La Santé (DMTS), SIMoS, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Denis Servent
- CEA, Département Médicaments et Technologies pour La Santé (DMTS), SIMoS, Université Paris-Saclay, Gif-sur-Yvette, France
- *Correspondence: Denis Servent,
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4
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Droctové L, Ciolek J, Mendre C, Chorfa A, Huerta P, Carvalho C, Gouin C, Lancien M, Stanajic-Petrovic G, Braco L, Blanchet G, Upert G, De Pauw E, Barbe P, Keck M, Mourier G, Mouillac B, Servent D, Rodríguez de la Vega RC, Quinton L, Gilles N. A new Kunitz-type snake toxin family associated with an original mode of interaction with the vasopressin 2 receptor. Br J Pharmacol 2022; 179:3470-3481. [PMID: 35122240 DOI: 10.1111/bph.15814] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 01/05/2022] [Accepted: 01/11/2022] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND AND PURPOSE Venomous animals express numerous Kunitz-type peptides. The mambaquaretin-1 (MQ1) identified from the Dendroaspis angusticeps venom is the most selective antagonist of the arginine-vasopressin V2 receptor (V2R) and the unique Kunitz-type peptide active on a GPCR. We aimed to exploit other mamba venoms to enlarge the V2R-Kunitz peptide family and gain insight into the MQ1 molecular mode of action. EXPERIMENTAL APPROACH We used a bio-guided screening assay to identify novel MQs and placed them phylogenetically. MQs were produced by solid phase peptide synthesis and characterized in vitro by binding and functional tests and in vivo by diuresis measurement in rats. KEY RESULTS Eight additional MQs were identified with nanomolar affinities for the V2R, all antagonists. MQs form a new subgroup in the Kunitz family, close to the V2R non-active dendrotoxins and to 2 V2R active cobra toxins. Sequence comparison between active and non-active V2R Kunitz peptides highlighted 5 positions, belong which, four are involved in V2R interaction and which belong to the 2 large MQ1 loops. We finally determined that 8 positions, part of these 2 loops, interact with the V2R. The variant MQ1-K39A showed higher affinity for the hV2R but not for the rat V2R. CONCLUSIONS AND IMPLICATIONS A new function and mode of action is now associated with the Kunitz-peptides. The number of MQ1 residues involved in V2R binding is large and may explain its absolute selectivity. MQ1-K39A represents the first step in the improvement of the MQ1 design for medicinal perspective.
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Affiliation(s)
- Laura Droctové
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SIMoS, Gif-sur-Yvette, France
| | - Justyna Ciolek
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SIMoS, Gif-sur-Yvette, France
| | - Christiane Mendre
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Amélia Chorfa
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Paola Huerta
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SIMoS, Gif-sur-Yvette, France
| | - Chrystelle Carvalho
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SIMoS, Gif-sur-Yvette, France
| | - Charlotte Gouin
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SIMoS, Gif-sur-Yvette, France
| | - Manon Lancien
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SIMoS, Gif-sur-Yvette, France
| | - Goran Stanajic-Petrovic
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SIMoS, Gif-sur-Yvette, France
| | - Lorine Braco
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SIMoS, Gif-sur-Yvette, France
| | - Guillaume Blanchet
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SIMoS, Gif-sur-Yvette, France
| | - Gregory Upert
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SIMoS, Gif-sur-Yvette, France
| | - Edwin De Pauw
- Laboratory of Mass Spectrometry, MolSys Research Unit, University of Liège, Liège, Belgium
| | - Peggy Barbe
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SIMoS, Gif-sur-Yvette, France
| | - Mathilde Keck
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SIMoS, Gif-sur-Yvette, France
| | - Gilles Mourier
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SIMoS, Gif-sur-Yvette, France
| | - Bernard Mouillac
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Denis Servent
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SIMoS, Gif-sur-Yvette, France
| | | | - Loïc Quinton
- Laboratory of Mass Spectrometry, MolSys Research Unit, University of Liège, Liège, Belgium
| | - Nicolas Gilles
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SIMoS, Gif-sur-Yvette, France
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5
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Averin AS, Utkin YN. Cardiovascular Effects of Snake Toxins: Cardiotoxicity and Cardioprotection. Acta Naturae 2021; 13:4-14. [PMID: 34707893 PMCID: PMC8526186 DOI: 10.32607/actanaturae.11375] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 04/13/2021] [Indexed: 12/11/2022] Open
Abstract
Snake venoms, as complex mixtures of peptides and proteins, affect various vital systems of the organism. One of the main targets of the toxic components from snake venoms is the cardiovascular system. Venom proteins and peptides can act in different ways, exhibiting either cardiotoxic or cardioprotective effects. The principal classes of these compounds are cobra cardiotoxins, phospholipases A2, and natriuretic, as well as bradykinin-potentiating peptides. There is another group of proteins capable of enhancing angiogenesis, which include, e.g., vascular endothelial growth factors possessing hypotensive and cardioprotective activities. Venom proteins and peptides exhibiting cardiotropic and vasoactive effects are promising candidates for the design of new drugs capable of preventing or constricting the development of pathological processes in cardiovascular diseases, which are currently the leading cause of death worldwide. For example, a bradykinin-potentiating peptide from Bothrops jararaca snake venom was the first snake venom compound used to create the widely used antihypertensive drugs captopril and enalapril. In this paper, we review the current state of research on snake venom components affecting the cardiovascular system and analyse the mechanisms of physiological action of these toxins and the prospects for their medical application.
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Affiliation(s)
- A. S. Averin
- Institute of Cell Biophysics of the Russian Academy of Sciences PSCBR RAS, Pushchino, Moscow region, 142290 Russia
| | - Yu. N. Utkin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997 Russia
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6
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Trim CM, Byrne LJ, Trim SA. Utilisation of compounds from venoms in drug discovery. PROGRESS IN MEDICINAL CHEMISTRY 2021; 60:1-66. [PMID: 34147202 DOI: 10.1016/bs.pmch.2021.01.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Difficult drug targets are becoming the normal course of business in drug discovery, sometimes due to large interacting surfaces or only small differences in selectivity regions. For these, a different approach is merited: compounds lying somewhere between the small molecule and the large antibody in terms of many properties including stability, biodistribution and pharmacokinetics. Venoms have evolved over millions of years to be complex mixtures of stable molecules derived from other somatic molecules, the stability comes from the pressure to be ready for delivery at a moment's notice. Snakes, spiders, scorpions, jellyfish, wasps, fish and even mammals have evolved independent venom systems with complex mixtures in their chemical arsenal. These venom-derived molecules have been proven to be useful tools, such as for the development of antihypotensive angiotensin converting enzyme (ACE) inhibitors and have also made successful drugs such as Byetta® (Exenatide), Integrilin® (Eptifibatide) and Echistatin. Only a small percentage of the available chemical space from venoms has been investigated so far and this is growing. In a new era of biological therapeutics, venom peptides present opportunities for larger target engagement surface with greater stability than antibodies or human peptides. There are challenges for oral absorption and target engagement, but there are venom structures that overcome these and thus provide substrate for engineering novel molecules that combine all desired properties. Venom researchers are characterising new venoms, species, and functions all the time, these provide great substrate for solving the challenges presented by today's difficult targets.
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Affiliation(s)
- Carol M Trim
- Faculty of Science, Engineering and Social Sciences, Natural and Applied Sciences, School of Psychology and Life Sciences, Canterbury Christ Church University, Canterbury, Kent, United Kingdom
| | - Lee J Byrne
- Faculty of Science, Engineering and Social Sciences, Natural and Applied Sciences, School of Psychology and Life Sciences, Canterbury Christ Church University, Canterbury, Kent, United Kingdom
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7
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Assessing the Binding of Venoms from Aquatic Elapids to the Nicotinic Acetylcholine Receptor Orthosteric Site of Different Prey Models. Int J Mol Sci 2020; 21:ijms21197377. [PMID: 33036249 PMCID: PMC7583753 DOI: 10.3390/ijms21197377] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 09/25/2020] [Accepted: 10/02/2020] [Indexed: 01/19/2023] Open
Abstract
The evolution of an aquatic lifestyle from land dwelling venomous elapids is a radical ecological modification, bringing about many evolutionary changes from morphology to diet. Diet is an important ecological facet which can play a key role in regulating functional traits such as venom composition and prey-specific targeting of venom. In addition to predating upon novel prey (e.g., fish, fish eggs and invertebrates), the venoms of aquatic elapids also face the challenge of increased prey-escape potential in the aquatic environment. Thus, despite the independent radiation into an aquatic niche on four separate occasions, the venoms of aquatic elapids are evolving under convergent selection pressures. Utilising a biolayer interferometry binding assay, this study set out to elucidate whether crude venoms from representative aquatic elapids were target-specific to the orthosteric site of postsynaptic nicotinic acetylcholine receptor mimotopes of fish compared to other terrestrial prey types. Representatives of the four aquatic lineages were: aquatic coral snakes representative was Micrurus surinamensis;, sea kraits representative was Laticauda colubrina; sea snakes representatives were two Aipysurus spp. and eight Hydrophis spp; and water cobras representative was Naja annulata. No prey-specific differences in crude venom binding were observed from any species tested, except for Aipysurus laevis, which showed slight evidence of prey-potency differences. For Hydrophis caerulescens, H. peronii, H. schistosus and M. surinamensis, there was a lack of binding to the orthosteric site of any target lineage. Subsequent testing on the in vitro chick-biventer cervicis muscle preparation suggested that, while the venoms of these species bound postsynaptically, they bound to allosteric sites rather than orthosteric. Allosteric binding is potentially a weaker but faster-acting form of neurotoxicity and we hypothesise that the switch to allosteric binding is likely due to selection pressures related to prey-escape potential. This research has potentially opened up the possibility of a new functional class of toxins which have never been assessed previously while shedding light on the selection pressures shaping venom evolution.
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8
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Reynaud S, Ciolek J, Degueldre M, Saez NJ, Sequeira AF, Duhoo Y, Brás JLA, Meudal H, Cabo Díez M, Fernández Pedrosa V, Verdenaud M, Boeri J, Pereira Ramos O, Ducancel F, Vanden Driessche M, Fourmy R, Violette A, Upert G, Mourier G, Beck-Sickinger AG, Mörl K, Landon C, Fontes CMGA, Miñambres Herráiz R, Rodríguez de la Vega RC, Peigneur S, Tytgat J, Quinton L, De Pauw E, Vincentelli R, Servent D, Gilles N. A Venomics Approach Coupled to High-Throughput Toxin Production Strategies Identifies the First Venom-Derived Melanocortin Receptor Agonists. J Med Chem 2020; 63:8250-8264. [PMID: 32602722 DOI: 10.1021/acs.jmedchem.0c00485] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Animal venoms are rich in hundreds of toxins with extraordinary biological activities. Their exploitation is difficult due to their complexity and the small quantities of venom available from most venomous species. We developed a Venomics approach combining transcriptomic and proteomic characterization of 191 species and identified 20,206 venom toxin sequences. Two complementary production strategies based on solid-phase synthesis and recombinant expression in Escherichia coli generated a physical bank of 3597 toxins. Screened on hMC4R, this bank gave an incredible hit rate of 8%. Here, we focus on two novel toxins: N-TRTX-Preg1a, exhibiting an inhibitory cystine knot (ICK) motif, and N-BUTX-Ptr1a, a short scorpion-CSαβ structure. Neither N-TRTX-Preg1a nor N-BUTX-Ptr1a affects ion channels, the known targets of their toxin scaffolds, but binds to four melanocortin receptors with low micromolar affinities and activates the hMC1R/Gs pathway. Phylogenetically, these two toxins form new groups within their respective families and represent novel hMC1R agonists, structurally unrelated to the natural agonists.
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Affiliation(s)
- Steve Reynaud
- Université Paris-Sud, 15 Rue Georges Clemenceau, Orsay 91405 France.,Université Paris Saclay, CEA, Département Médicaments et Technologies pour la Santé, SIMoS, Gif-sur-Yvette 91191 France
| | - Justyna Ciolek
- Université Paris Saclay, CEA, Département Médicaments et Technologies pour la Santé, SIMoS, Gif-sur-Yvette 91191 France
| | - Michel Degueldre
- Mass Spectrometry Laboratory, Université de Liège, Allée du six Aout 11, Quartier Agora, Liege 4000 Belgium.,Department of Analytical Science Biologicals, UCB, Chemin du Foriest, Braine L'Alleud 1420 Belgium
| | - Natalie J Saez
- Centre National de la Recherche Scientifique, Architecture et Fonction des Macromolécules Biologiques, Campus de Luminy, Marseille 13288 France.,Institute for Molecular Bioscience, The University of Queensland, St Lucia 4072, QLD, Australia
| | - Ana Filipa Sequeira
- Universidade de Lisboa, CIISA - Faculdade de Medicina Veterinária, Avenida da Universidade Técnica, Lisboa 1300-477 Portugal.,NZYTech Lda, Genes & Enzymes, Estrada do Paço do Lumiar, Campus do Lumiar, Edifício E - R/C, Lisboa 1649-038 Portugal
| | - Yoan Duhoo
- Centre National de la Recherche Scientifique, Architecture et Fonction des Macromolécules Biologiques, Campus de Luminy, Marseille 13288 France.,Institute for Molecular Bioscience, The University of Queensland, St Lucia 4072, QLD, Australia
| | - Joana L A Brás
- Universidade de Lisboa, CIISA - Faculdade de Medicina Veterinária, Avenida da Universidade Técnica, Lisboa 1300-477 Portugal.,NZYTech Lda, Genes & Enzymes, Estrada do Paço do Lumiar, Campus do Lumiar, Edifício E - R/C, Lisboa 1649-038 Portugal
| | - Hervé Meudal
- Centre National de la Recherche Scientifique, Centre de Biophysique Moléculaire, rue Charles Sadron, Orléans 45071 France
| | - Miguel Cabo Díez
- Next-Generation Sequencing Laboratory, Sistemas Genómicos Ltd., Ronda de Guglielmo Marconi, 6, Paterna 46980 Spain
| | - Victoria Fernández Pedrosa
- Next-Generation Sequencing Laboratory, Sistemas Genómicos Ltd., Ronda de Guglielmo Marconi, 6, Paterna 46980 Spain
| | - Marion Verdenaud
- Université Paris Saclay, CEA, Département Médicaments et Technologies pour la Santé, SIMoS, Gif-sur-Yvette 91191 France
| | - Julia Boeri
- Université Paris Saclay, CEA, Département Médicaments et Technologies pour la Santé, SIMoS, Gif-sur-Yvette 91191 France
| | - Oscar Pereira Ramos
- Université Paris Saclay, CEA, Département Médicaments et Technologies pour la Santé, SIMoS, Gif-sur-Yvette 91191 France
| | - Frédéric Ducancel
- Université Paris Saclay, CEA, Département IDMIT, 18 route du Panorama, 92265 Fontenay-aux-Roses, France
| | - Margot Vanden Driessche
- Université Paris Saclay, CEA, Département Médicaments et Technologies pour la Santé, SIMoS, Gif-sur-Yvette 91191 France
| | - Rudy Fourmy
- Alphabiotoxine Laboratory sprl, Barberie 15, Montroeul-au-bois 7911 Belgium
| | - Aude Violette
- Alphabiotoxine Laboratory sprl, Barberie 15, Montroeul-au-bois 7911 Belgium
| | - Grégory Upert
- Université Paris Saclay, CEA, Département Médicaments et Technologies pour la Santé, SIMoS, Gif-sur-Yvette 91191 France
| | - Gilles Mourier
- Université Paris Saclay, CEA, Département Médicaments et Technologies pour la Santé, SIMoS, Gif-sur-Yvette 91191 France
| | | | - Karin Mörl
- Institute of Biochemistry, Universitat Leipzig, Leipzig 04103 Germany
| | - Céline Landon
- Centre National de la Recherche Scientifique, Centre de Biophysique Moléculaire, rue Charles Sadron, Orléans 45071 France
| | - Carlos M G A Fontes
- Universidade de Lisboa, CIISA - Faculdade de Medicina Veterinária, Avenida da Universidade Técnica, Lisboa 1300-477 Portugal.,NZYTech Lda, Genes & Enzymes, Estrada do Paço do Lumiar, Campus do Lumiar, Edifício E - R/C, Lisboa 1649-038 Portugal
| | - Rebeca Miñambres Herráiz
- Next-Generation Sequencing Laboratory, Sistemas Genómicos Ltd., Ronda de Guglielmo Marconi, 6, Paterna 46980 Spain
| | | | - Steve Peigneur
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Herestraat 49, Leuven 3000 Belgium
| | - Jan Tytgat
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Herestraat 49, Leuven 3000 Belgium
| | - Loïc Quinton
- Mass Spectrometry Laboratory, Université de Liège, Allée du six Aout 11, Quartier Agora, Liege 4000 Belgium
| | - Edwin De Pauw
- Mass Spectrometry Laboratory, Université de Liège, Allée du six Aout 11, Quartier Agora, Liege 4000 Belgium
| | - Renaud Vincentelli
- Centre National de la Recherche Scientifique, Architecture et Fonction des Macromolécules Biologiques, Campus de Luminy, Marseille 13288 France
| | - Denis Servent
- Université Paris Saclay, CEA, Département Médicaments et Technologies pour la Santé, SIMoS, Gif-sur-Yvette 91191 France
| | - Nicolas Gilles
- Université Paris Saclay, CEA, Département Médicaments et Technologies pour la Santé, SIMoS, Gif-sur-Yvette 91191 France
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9
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Nirthanan S. Snake three-finger α-neurotoxins and nicotinic acetylcholine receptors: molecules, mechanisms and medicine. Biochem Pharmacol 2020; 181:114168. [PMID: 32710970 DOI: 10.1016/j.bcp.2020.114168] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/20/2020] [Accepted: 07/20/2020] [Indexed: 12/13/2022]
Abstract
Snake venom three-finger α-neurotoxins (α-3FNTx) act on postsynaptic nicotinic acetylcholine receptors (nAChRs) at the neuromuscular junction (NMJ) to produce skeletal muscle paralysis. The discovery of the archetypal α-bungarotoxin (α-BgTx), almost six decades ago, exponentially expanded our knowledge of membrane receptors and ion channels. This included the localisation, isolation and characterization of the first receptor (nAChR); and by extension, the pathophysiology and pharmacology of neuromuscular transmission and associated pathologies such as myasthenia gravis, as well as our understanding of the role of α-3FNTxs in snakebite envenomation leading to novel concepts of targeted treatment. Subsequent studies on a variety of animal venoms have yielded a plethora of novel toxins that have revolutionized molecular biomedicine and advanced drug discovery from bench to bedside. This review provides an overview of nAChRs and their subtypes, classification of α-3FNTxs and the challenges of typifying an increasing arsenal of structurally and functionally unique toxins, and the three-finger protein (3FP) fold in the context of the uPAR/Ly6/CD59/snake toxin superfamily. The pharmacology of snake α-3FNTxs including their mechanisms of neuromuscular blockade, variations in reversibility of nAChR interactions, specificity for nAChR subtypes or for distinct ligand-binding interfaces within a subtype and the role of α-3FNTxs in neurotoxic envenomation are also detailed. Lastly, a reconciliation of structure-function relationships between α-3FNTx and nAChRs, derived from historical mutational and biochemical studies and emerging atomic level structures of nAChR models in complex with α-3FNTxs is discussed.
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Affiliation(s)
- Selvanayagam Nirthanan
- School of Medical Science, Griffith Health Group, Griffith University, Gold Coast, Queensland, Australia.
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10
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Kini RM, Koh CY. Snake venom three-finger toxins and their potential in drug development targeting cardiovascular diseases. Biochem Pharmacol 2020; 181:114105. [PMID: 32579959 DOI: 10.1016/j.bcp.2020.114105] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 06/13/2020] [Accepted: 06/17/2020] [Indexed: 12/15/2022]
Abstract
Cardiovascular diseases such as coronary and peripheral artery diseases, venous thrombosis, stroke, hypertension, and heart failure are enormous burden to health and economy globally. Snake venoms have been the sources of discovery of successful therapeutics targeting cardiovascular diseases. For example, the first-in-class angiotensin-converting enzyme inhibitor captopril was designed largely based on bradykinin-potentiating peptides from Bothrops jararaca venom. In the recent years, sensitive and high throughput approaches drive discovery and cataloging of new snake venom toxins. As one of the largest class of snake venom toxin, there are now>700 sequences of three-finger toxins (3FTxs) available, many of which are yet to be studied. While the function of 3FTxs are normally associated with neurotoxicity, increasingly more 3FTxs have been characterized to have pharmacological effects on cardiovascular systems. Here we focus on this family of snake venom toxins and their potential in developing therapeutics against cardiovascular diseases.
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Affiliation(s)
- R Manjunatha Kini
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 117558, Singapore; Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, 117600, Singapore
| | - Cho Yeow Koh
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 119228, Singapore.
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11
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Muratspahić E, Freissmuth M, Gruber CW. Nature-Derived Peptides: A Growing Niche for GPCR Ligand Discovery. Trends Pharmacol Sci 2019; 40:309-326. [PMID: 30955896 DOI: 10.1016/j.tips.2019.03.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 02/26/2019] [Accepted: 03/06/2019] [Indexed: 12/11/2022]
Abstract
G protein-coupled receptors (GPCRs) represent important drug targets, as they regulate pivotal physiological processes and they have proved to be readily druggable. Natural products have been and continue to be amongst the most valuable sources for drug discovery and development. Here, we surveyed small molecules and (poly-)peptides derived from plants, animals, fungi, and bacteria, which modulate GPCR signaling. Among naturally occurring compounds, peptides from plants, cone-snails, snakes, spiders, scorpions, fungi, and bacteria are of particular interest as lead compounds for the development of GPCR ligands, since they cover a chemical space, which differs from that of synthetic small molecules. Peptides, however, face challenges, some of which can be overcome by studying plant-derived compounds. We argue here that the opportunities outweigh the challenges.
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Affiliation(s)
- Edin Muratspahić
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Austria
| | - Michael Freissmuth
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Austria; Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center for Physiology and Pharmacology, Medical University of Vienna, Austria
| | - Christian W Gruber
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Austria.
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12
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Utkin YN. Last decade update for three-finger toxins: Newly emerging structures and biological activities. World J Biol Chem 2019; 10:17-27. [PMID: 30622682 PMCID: PMC6314878 DOI: 10.4331/wjbc.v10.i1.17] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 11/20/2018] [Accepted: 12/05/2018] [Indexed: 02/05/2023] Open
Abstract
Three-finger toxins (TFTs) comprise one of largest families of snake venom toxins. While they are principal to and the most toxic components of the venoms of the Elapidae snake family, their presence has also been detected in the venoms of snakes from other families. The first TFT, α-bungarotoxin, was discovered almost 50 years ago and has since been used widely as a specific marker of the α7 and muscle-type nicotinic acetylcholine receptors. To date, the number of TFT amino acid sequences deposited in the UniProt Knowledgebase free-access database is more than 700, and new members are being added constantly. Although structural variations among the TFTs are not numerous, several new structures have been discovered recently; these include the disulfide-bound dimers of TFTs and toxins with nonstandard pairing of disulfide bonds. New types of biological activities have also been demonstrated for the well-known TFTs, and research on this topic has become a hot topic of TFT studies. The classic TFTs α-bungarotoxin and α-cobratoxin, for example, have now been shown to inhibit ionotropic receptors of γ-aminobutyric acid, and some muscarinic toxins have been shown to interact with adrenoceptors. New, unexpected activities have been demonstrated for some TFTs as well, such as toxin interaction with interleukin or insulin receptors and even TFT-activated motility of sperm. This minireview provides a summarization of the data that has emerged in the last decade on the TFTs and their activities.
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Affiliation(s)
- Yuri N Utkin
- Laboratory of Molecular Toxinology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow 117997, Russia
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In-Depth Glyco-Peptidomics Approach Reveals Unexpected Diversity of Glycosylated Peptides and Atypical Post-Translational Modifications in Dendroaspis angusticeps Snake Venom. Int J Mol Sci 2017; 18:ijms18112453. [PMID: 29156586 PMCID: PMC5713420 DOI: 10.3390/ijms18112453] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 11/08/2017] [Accepted: 11/09/2017] [Indexed: 11/16/2022] Open
Abstract
Animal venoms represent a valuable source of bioactive peptides that can be derived into useful pharmacological tools, or even innovative drugs. In this way, the venom of Dendroaspis angusticeps (DA), the Eastern Green Mamba, has been intensively studied during recent years. It mainly contains hundreds of large toxins from 6 to 9 kDa, each displaying several disulfide bridges. These toxins are the main target of venom-based studies due to their valuable activities obtained by selectively targeting membrane receptors, such as ion channels or G-protein coupled receptors. This study aims to demonstrate that the knowledge of venom composition is still limited and that animal venoms contain unexpected diversity and surprises. A previous study has shown that Dendroaspis angusticeps venom contains not only a cocktail of classical toxins, but also small glycosylated peptides. Following this work, a deep exploration of DA glycopeptidome by a dual nano liquid chromatography coupled to electrospray ionization mass spectrometry (nanoLC-ESI-MS) and Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) analyses was initiated. This study reveals unsuspected structural diversity of compounds such as 221 glycopeptides, displaying different glycan structures. Sequence alignments underline structural similarities with natriuretic peptides already characterized in Elapidae venoms. Finally, the presence of an S-cysteinylation and hydroxylation of proline on four glycopeptides, never described to date in snake venoms, is also revealed by proteomics and affined by nuclear magnetic resonance (NMR) experiments.
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G-Protein Coupled Receptors Targeted by Analgesic Venom Peptides. Toxins (Basel) 2017; 9:toxins9110372. [PMID: 29144441 PMCID: PMC5705987 DOI: 10.3390/toxins9110372] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 11/13/2017] [Accepted: 11/13/2017] [Indexed: 12/14/2022] Open
Abstract
Chronic pain is a complex and debilitating condition associated with a large personal and socioeconomic burden. Current pharmacological approaches to treating chronic pain such as opioids, antidepressants and anticonvulsants exhibit limited efficacy in many patients and are associated with dose-limiting side effects that hinder their clinical use. Therefore, improved strategies for the pharmacological treatment of pathological pain are urgently needed. G-protein coupled receptors (GPCRs) are ubiquitously expressed on the surface of cells and act to transduce extracellular signals and regulate physiological processes. In the context of pain, numerous and diverse families of GPCRs expressed in pain pathways regulate most aspects of physiological and pathological pain and are thus implicated as potential targets for therapy of chronic pain. In the search for novel compounds that produce analgesia via GPCR modulation, animal venoms offer an enormous and virtually untapped source of potent and selective peptide molecules. While many venom peptides target voltage-gated and ligand-gated ion channels to inhibit neuronal excitability and blunt synaptic transmission of pain signals, only a small proportion are known to interact with GPCRs. Of these, only a few have shown analgesic potential in vivo. Here we review the current state of knowledge regarding venom peptides that target GPCRs to produce analgesia, and their development as therapeutic compounds.
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Green mamba peptide targets type-2 vasopressin receptor against polycystic kidney disease. Proc Natl Acad Sci U S A 2017. [PMID: 28630289 DOI: 10.1073/pnas.1620454114] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Polycystic kidney diseases (PKDs) are genetic disorders that can cause renal failure and death in children and adults. Lowering cAMP in cystic tissues through the inhibition of the type-2 vasopressin receptor (V2R) constitutes a validated strategy to reduce disease progression. We identified a peptide from green mamba venom that exhibits nanomolar affinity for the V2R without any activity on 155 other G-protein-coupled receptors or on 15 ionic channels. Mambaquaretin-1 is a full antagonist of the V2R activation pathways studied: cAMP production, beta-arrestin interaction, and MAP kinase activity. This peptide adopts the Kunitz fold known to mostly act on potassium channels and serine proteases. Mambaquaretin-1 interacts selectively with the V2R through its first loop, in the same manner that aprotinin inhibits trypsin. Injected in mice, mambaquaretin-1 increases in a dose-dependent manner urine outflow with concomitant reduction of urine osmolality, indicating a purely aquaretic effect associated with the in vivo blockade of V2R. CD1-pcy/pcy mice, a juvenile model of PKD, daily treated with 13 [Formula: see text]g of mambaquaretin-1 for 99 d, developed less abundant (by 33%) and smaller (by 47%) cysts than control mice. Neither tachyphylaxis nor apparent toxicity has been noted. Mambaquaretin-1 represents a promising therapeutic agent against PKDs.
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Ancestral protein resurrection and engineering opportunities of the mamba aminergic toxins. Sci Rep 2017; 7:2701. [PMID: 28578406 PMCID: PMC5457417 DOI: 10.1038/s41598-017-02953-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 04/25/2017] [Indexed: 12/17/2022] Open
Abstract
Mamba venoms contain a multiplicity of three-finger fold aminergic toxins known to interact with various α-adrenergic, muscarinic and dopaminergic receptors with different pharmacological profiles. In order to generate novel functions on this structural scaffold and to avoid the daunting task of producing and screening an overwhelming number of variants generated by a classical protein engineering strategy, we accepted the challenge of resurrecting ancestral proteins, likely to have possessed functional properties. This innovative approach that exploits molecular evolution models to efficiently guide protein engineering, has allowed us to generate a small library of six ancestral toxin (AncTx) variants and associate their pharmacological profiles to key functional substitutions. Among these variants, we identified AncTx1 as the most α1A-adrenoceptor selective peptide known to date and AncTx5 as the most potent inhibitor of the three α2 adrenoceptor subtypes. Three positions in the ρ-Da1a evolutionary pathway, positions 28, 38 and 43 have been identified as key modulators of the affinities for the α1 and α2C adrenoceptor subtypes. Here, we present a first attempt at rational engineering of the aminergic toxins, revealing an epistasis phenomenon.
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Kessler P, Marchot P, Silva M, Servent D. The three-finger toxin fold: a multifunctional structural scaffold able to modulate cholinergic functions. J Neurochem 2017; 142 Suppl 2:7-18. [PMID: 28326549 DOI: 10.1111/jnc.13975] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 01/12/2017] [Accepted: 01/30/2017] [Indexed: 12/26/2022]
Abstract
Three-finger fold toxins are miniproteins frequently found in Elapidae snake venoms. This fold is characterized by three distinct loops rich in β-strands and emerging from a dense, globular core reticulated by four highly conserved disulfide bridges. The number and diversity of receptors, channels, and enzymes identified as targets of three-finger fold toxins is increasing continuously. Such manifold diversity highlights the specific adaptability of this fold for generating pleiotropic functions. Although this toxin superfamily disturbs many biological functions by interacting with a large diversity of molecular targets, the most significant target is the cholinergic system. By blocking the activity of the nicotinic and muscarinic acetylcholine receptors or by inhibiting the enzyme acetylcholinesterase, three-finger fold toxins interfere most drastically with neuromuscular junction functioning. Several of these toxins have become powerful pharmacological tools for studying the function and structure of their molecular targets. Most importantly, since dysfunction of these receptors/enzyme is involved in many diseases, exploiting the three-finger scaffold to create novel, highly specific therapeutic agents may represent a major future endeavor. This is an article for the special issue XVth International Symposium on Cholinergic Mechanisms.
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Affiliation(s)
- Pascal Kessler
- Service d'Ingénierie Moléculaire des Protéines (SIMOPRO), IBITECS, CEA, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Pascale Marchot
- Aix-Marseille Université/Centre National de la Recherche Scientifique, Architecture et Fonction des Macromolécules Biologiques laboratory, Faculté des Sciences Campus Luminy, Marseille, France
| | - Marcela Silva
- Service d'Ingénierie Moléculaire des Protéines (SIMOPRO), IBITECS, CEA, Université Paris-Saclay, Gif-sur-Yvette, France.,Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Denis Servent
- Service d'Ingénierie Moléculaire des Protéines (SIMOPRO), IBITECS, CEA, Université Paris-Saclay, Gif-sur-Yvette, France
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18
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Upert G, Mourier G, Pastor A, Verdenaud M, Alili D, Servent D, Gilles N. High-throughput production of two disulphide-bridge toxins. Chem Commun (Camb) 2015; 50:8408-11. [PMID: 24947561 DOI: 10.1039/c4cc02679a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A quick and efficient production method compatible with high-throughput screening was developed using 36 toxins belonging to four different families of two disulphide-bridge toxins. Final toxins were characterized using HPLC co-elution, CD and pharmacological studies.
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Affiliation(s)
- Grégory Upert
- CEA, DSV, iBiTec-S, Service d'Ingénierie Moléculaire des Protéines (SIMOPRO), CEA Saclay, Gif sur Yvette F-91191, France.
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19
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Polypharmacology profiles and phylogenetic analysis of three-finger toxins from mamba venom: Case of aminergic toxins. Biochimie 2014; 103:109-17. [DOI: 10.1016/j.biochi.2014.04.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 04/22/2014] [Indexed: 12/21/2022]
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20
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Isolation, Functional Characterization and Proteomic Identification of CC2-PLA2 from Cerastes cerastes Venom: A Basic Platelet-Aggregation-Inhibiting Factor. Protein J 2014; 33:61-74. [DOI: 10.1007/s10930-013-9534-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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21
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Alexander SPH, Benson HE, Faccenda E, Pawson AJ, Sharman JL, Spedding M, Peters JA, Harmar AJ. The Concise Guide to PHARMACOLOGY 2013/14: G protein-coupled receptors. Br J Pharmacol 2013; 170:1459-581. [PMID: 24517644 PMCID: PMC3892287 DOI: 10.1111/bph.12445] [Citation(s) in RCA: 505] [Impact Index Per Article: 45.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The Concise Guide to PHARMACOLOGY 2013/14 provides concise overviews of the key properties of over 2000 human drug targets with their pharmacology, plus links to an open access knowledgebase of drug targets and their ligands (www.guidetopharmacology.org), which provides more detailed views of target and ligand properties. The full contents can be found at http://onlinelibrary.wiley.com/doi/10.1111/bph.12444/full. G protein-coupled receptors are one of the seven major pharmacological targets into which the Guide is divided, with the others being G protein-coupled receptors, ligand-gated ion channels, ion channels, catalytic receptors, nuclear hormone receptors, transporters and enzymes. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. A new landscape format has easy to use tables comparing related targets. It is a condensed version of material contemporary to late 2013, which is presented in greater detail and constantly updated on the website www.guidetopharmacology.org, superseding data presented in previous Guides to Receptors and Channels. It is produced in conjunction with NC-IUPHAR and provides the official IUPHAR classification and nomenclature for human drug targets, where appropriate. It consolidates information previously curated and displayed separately in IUPHAR-DB and the Guide to Receptors and Channels, providing a permanent, citable, point-in-time record that will survive database updates.
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Affiliation(s)
- Stephen PH Alexander
- School of Life Sciences, University of Nottingham Medical SchoolNottingham, NG7 2UH, UK
| | - Helen E Benson
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | - Elena Faccenda
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | - Adam J Pawson
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | - Joanna L Sharman
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | | | - John A Peters
- Neuroscience Division, Medical Education Institute, Ninewells Hospital and Medical School, University of DundeeDundee, DD1 9SY, UK
| | - Anthony J Harmar
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
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Three-fingered RAVERs: Rapid Accumulation of Variations in Exposed Residues of snake venom toxins. Toxins (Basel) 2013; 5:2172-208. [PMID: 24253238 PMCID: PMC3847720 DOI: 10.3390/toxins5112172] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 11/08/2013] [Accepted: 11/11/2013] [Indexed: 12/21/2022] Open
Abstract
Three-finger toxins (3FTx) represent one of the most abundantly secreted and potently toxic components of colubrid (Colubridae), elapid (Elapidae) and psammophid (Psammophiinae subfamily of the Lamprophidae) snake venom arsenal. Despite their conserved structural similarity, they perform a diversity of biological functions. Although they are theorised to undergo adaptive evolution, the underlying diversification mechanisms remain elusive. Here, we report the molecular evolution of different 3FTx functional forms and show that positively selected point mutations have driven the rapid evolution and diversification of 3FTx. These diversification events not only correlate with the evolution of advanced venom delivery systems (VDS) in Caenophidia, but in particular the explosive diversification of the clade subsequent to the evolution of a high pressure, hollow-fanged VDS in elapids, highlighting the significant role of these toxins in the evolution of advanced snakes. We show that Type I, II and III α-neurotoxins have evolved with extreme rapidity under the influence of positive selection. We also show that novel Oxyuranus/Pseudonaja Type II forms lacking the apotypic loop-2 stabilising cysteine doublet characteristic of Type II forms are not phylogenetically basal in relation to other Type IIs as previously thought, but are the result of secondary loss of these apotypic cysteines on at least three separate occasions. Not all 3FTxs have evolved rapidly: κ-neurotoxins, which form non-covalently associated heterodimers, have experienced a relatively weaker influence of diversifying selection; while cytotoxic 3FTx, with their functional sites, dispersed over 40% of the molecular surface, have been extremely constrained by negative selection. We show that the a previous theory of 3FTx molecular evolution (termed ASSET) is evolutionarily implausible and cannot account for the considerable variation observed in very short segments of 3FTx. Instead, we propose a theory of Rapid Accumulation of Variations in Exposed Residues (RAVER) to illustrate the significance of point mutations, guided by focal mutagenesis and positive selection in the evolution and diversification of 3FTx.
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Maïga A, Merlin J, Marcon E, Rouget C, Larregola M, Gilquin B, Fruchart-Gaillard C, Lajeunesse E, Marchetti C, Lorphelin A, Bellanger L, Summers RJ, Hutchinson DS, Evans BA, Servent D, Gilles N. Orthosteric binding of ρ-Da1a, a natural peptide of snake venom interacting selectively with the α1A-adrenoceptor. PLoS One 2013; 8:e68841. [PMID: 23935897 PMCID: PMC3723878 DOI: 10.1371/journal.pone.0068841] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 06/01/2013] [Indexed: 01/02/2023] Open
Abstract
ρ-Da1a is a three-finger fold toxin from green mamba venom that is highly selective for the α1A-adrenoceptor. This toxin has atypical pharmacological properties, including incomplete inhibition of 3H-prazosin or 125I-HEAT binding and insurmountable antagonist action. We aimed to clarify its mode of action at the α1A-adrenoceptor. The affinity (pKi 9.26) and selectivity of ρ-Da1a for the α1A-adrenoceptor were confirmed by comparing binding to human adrenoceptors expressed in eukaryotic cells. Equilibrium and kinetic binding experiments were used to demonstrate that ρ-Da1a, prazosin and HEAT compete at the α1A-adrenoceptor. ρ-Da1a did not affect the dissociation kinetics of 3H-prazosin or 125I-HEAT, and the IC50 of ρ-Da1a, determined by competition experiments, increased linearly with the concentration of radioligands used, while the residual binding by ρ-Da1a remained stable. The effect of ρ-Da1a on agonist-stimulated Ca2+ release was insurmountable in the presence of phenethylamine- or imidazoline-type agonists. Ten mutations in the orthosteric binding pocket of the α1A-adrenoceptor were evaluated for alterations in ρ-Da1a affinity. The D1063.32A and the S1885.42A/S1925.46A receptor mutations reduced toxin affinity moderately (6 and 7.6 times, respectively), while the F862.64A, F2886.51A and F3127.39A mutations diminished it dramatically by 18- to 93-fold. In addition, residue F862.64 was identified as a key interaction point for 125I-HEAT, as the variant F862.64A induced a 23-fold reduction in HEAT affinity. Unlike the M1 muscarinic acetylcholine receptor toxin MT7, ρ-Da1a interacts with the human α1A-adrenoceptor orthosteric pocket and shares receptor interaction points with antagonist (F862.64, F2886.51 and F3127.39) and agonist (F2886.51 and F3127.39) ligands. Its selectivity for the α1A-adrenoceptor may result, at least partly, from its interaction with the residue F862.64, which appears to be important also for HEAT binding.
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Affiliation(s)
- Arhamatoulaye Maïga
- Commissariat à l'énergie atomique et aux énergies alternatives, iBiTec-S, Service d'Ingénierie Moléculaire des Protéines, Gif sur Yvette, France
| | - Jon Merlin
- Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Elodie Marcon
- Commissariat à l'énergie atomique et aux énergies alternatives, iBiTec-S, Service d'Ingénierie Moléculaire des Protéines, Gif sur Yvette, France
| | - Céline Rouget
- Commissariat à l'énergie atomique et aux énergies alternatives, iBiTec-S, Service d'Ingénierie Moléculaire des Protéines, Gif sur Yvette, France
| | - Maud Larregola
- Commissariat à l'énergie atomique et aux énergies alternatives, iBiTec-S, Service d'Ingénierie Moléculaire des Protéines, Gif sur Yvette, France
| | - Bernard Gilquin
- Commissariat à l'énergie atomique et aux énergies alternatives, iBiTec-S, Service de Bioénergétique, Biologie Structurale et Mécanismes, Gif sur Yvette, France
| | - Carole Fruchart-Gaillard
- Commissariat à l'énergie atomique et aux énergies alternatives, iBiTec-S, Service d'Ingénierie Moléculaire des Protéines, Gif sur Yvette, France
| | - Evelyne Lajeunesse
- Commissariat à l'énergie atomique et aux énergies alternatives, iBiTec-S, Service d'Ingénierie Moléculaire des Protéines, Gif sur Yvette, France
| | - Charles Marchetti
- Commissariat à l'énergie atomique et aux énergies alternatives, iBEB, Service de Biochimie et Toxicologie Nucléaire, Bagnols-sur-Cèze Cedex, France
| | - Alain Lorphelin
- Commissariat à l'énergie atomique et aux énergies alternatives, iBEB, Service de Biochimie et Toxicologie Nucléaire, Bagnols-sur-Cèze Cedex, France
| | - Laurent Bellanger
- Commissariat à l'énergie atomique et aux énergies alternatives, iBEB, Service de Biochimie et Toxicologie Nucléaire, Bagnols-sur-Cèze Cedex, France
| | - Roger J. Summers
- Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Dana S. Hutchinson
- Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Bronwyn A. Evans
- Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Denis Servent
- Commissariat à l'énergie atomique et aux énergies alternatives, iBiTec-S, Service d'Ingénierie Moléculaire des Protéines, Gif sur Yvette, France
| | - Nicolas Gilles
- Commissariat à l'énergie atomique et aux énergies alternatives, iBiTec-S, Service d'Ingénierie Moléculaire des Protéines, Gif sur Yvette, France
- * E-mail:
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Palea S, Maiga A, Guilloteau V, Rekik M, Guérard M, Rouget C, Rischmann P, Botto H, Camparo P, Lluel P, Gilles N. Effects of ρ-Da1a a peptidic α(1) (A) -adrenoceptor antagonist in human isolated prostatic adenoma and anaesthetized rats. Br J Pharmacol 2013; 168:618-31. [PMID: 23005263 DOI: 10.1111/j.1476-5381.2012.02231.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Revised: 07/09/2012] [Accepted: 08/08/2012] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE ρ-Da1a, a 65 amino-acid peptide, has subnanomolar affinity and high selectivity for the human α(1) (A) -adrenoceptor subtype. The purpose of this study was to characterize the pharmacological effects of ρ-Da1a on prostatic function, both in vivo and in vitro. EXPERIMENTAL APPROACH ρ-Da1a was tested as an antagonist of adrenaline-induced effects on COS cells transfected with the human α(1) (A) -adrenoceptor as well as on human isolated prostatic adenoma obtained from patients suffering from benign prostatic hyperplasia. Moreover, we compared the effects of ρ-Da1a and tamsulosin on phenylephrine (PHE)-induced increases in intra-urethral (IUP) and arterial pressures (AP) in anaesthetized rats, following i.v. or p.o. administration. KEY RESULTS On COS cells expressing human α(1) (A) -adrenoceptors and on human prostatic strips, ρ-Da1a inhibited adrenaline- and noradrenaline-induced effects. In anaesthetized rats, ρ-Da1a and tamsulosin administered i.v. 30 min before PHE significantly antagonized the effects of PHE on IUP. The pK(B) values for tamsulosin and ρ-Da1a for this effect were similar. With regards to AP, ρ-Da1a only reduced the effect of PHE on AP at the lowest dose tested (10 μg·kg(-1) ), whereas tamsulosin significantly reduced PHE effects at doses between 10 and 150 μg·kg(-1) . CONCLUSIONS AND IMPLICATIONS ρ-Da1a exhibited a relevant effect on IUP and a small effect on AP. In contrast, tamsulosin antagonized the effects of PHE on both IUP and AP. We conclude that ρ-Da1a is more uroselective than tamsulosin. ρ-Da1a is the most selective peptidic antagonist for α(1A) -adenoceptors identified to date and could be a new treatment for various urological diseases.
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Affiliation(s)
- S Palea
- UROsphere, Faculté des Sciences Pharmaceutiques, Toulouse, France.
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Maïga A, Vera L, Marchetti C, Lorphelin A, Bellanger L, Mourier G, Servent D, Gilles N, Stura EA. Crystallization of recombinant green mamba ρ-Da1a toxin during a lyophilization procedure and its structure determination. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:704-9. [PMID: 23722859 PMCID: PMC3668600 DOI: 10.1107/s1744309113011470] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Accepted: 04/26/2013] [Indexed: 11/10/2022]
Abstract
ρ-Da1a toxin from eastern green mamba (Dendroaspis angusticeps) venom is a polypeptide of 65 amino acids with a strong affinity for the G-protein-coupled α(1A)-adrenoceptor. This neurotoxin has been crystallized from resolubilized lyophilized powder, but the best crystals grew spontaneously during lyophilization. The crystals belonged to the trigonal space group P3(1)21, with unit-cell parameters a = b = 37.37, c = 66.05 Å, and diffracted to 1.95 Å resolution. The structure solved by molecular replacement showed strong similarities to green mamba muscarinic toxins.
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Affiliation(s)
- Arhamatoulaye Maïga
- CEA, DSV, iBiTec-S, Service d’Ingénierie Moléculaire des Protéines (SIMOPRO), 91191 Gif-sur-Yvette, France
| | - Laura Vera
- CEA, DSV, iBiTec-S, Service d’Ingénierie Moléculaire des Protéines (SIMOPRO), 91191 Gif-sur-Yvette, France
| | - Charles Marchetti
- CEA, DSV, iBEB, Service de Biochimie et Toxicologie Nucléaire, Centre de Marcoule, BP 17171, 30207 Bagnols-sur-Cèze CEDEX, France
| | - Alain Lorphelin
- CEA, DSV, iBEB, Service de Biochimie et Toxicologie Nucléaire, Centre de Marcoule, BP 17171, 30207 Bagnols-sur-Cèze CEDEX, France
| | - Laurent Bellanger
- CEA, DSV, iBEB, Service de Biochimie et Toxicologie Nucléaire, Centre de Marcoule, BP 17171, 30207 Bagnols-sur-Cèze CEDEX, France
| | - Gilles Mourier
- CEA, DSV, iBiTec-S, Service d’Ingénierie Moléculaire des Protéines (SIMOPRO), 91191 Gif-sur-Yvette, France
| | - Denis Servent
- CEA, DSV, iBiTec-S, Service d’Ingénierie Moléculaire des Protéines (SIMOPRO), 91191 Gif-sur-Yvette, France
| | - Nicolas Gilles
- CEA, DSV, iBiTec-S, Service d’Ingénierie Moléculaire des Protéines (SIMOPRO), 91191 Gif-sur-Yvette, France
| | - Enrico Adriano Stura
- CEA, DSV, iBiTec-S, Service d’Ingénierie Moléculaire des Protéines (SIMOPRO), 91191 Gif-sur-Yvette, France
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Blanchet G, Upert G, Mourier G, Gilquin B, Gilles N, Servent D. New α-adrenergic property for synthetic MTβ and CM-3 three-finger fold toxins from black mamba. Toxicon 2013; 75:160-7. [PMID: 23648423 DOI: 10.1016/j.toxicon.2013.04.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 04/15/2013] [Accepted: 04/19/2013] [Indexed: 12/28/2022]
Abstract
Despite their isolation more than fifteen years ago from the venom of the African mamba Dendroaspis polylepis, very few data are known on the functional activity of MTβ and CM-3 toxins. MTβ was initially classified as a muscarinic toxin interacting non-selectively and with low affinity with the five muscarinic receptor subtypes while no biological function was determined for CM-3. Recent results highlight the multifunctional activity of three-finger fold toxins for muscarinic and adrenergic receptors and reveal some discrepancies in the pharmacological profiles of their venom-purified and synthetic forms. Here, we report the pharmacological characterization of chemically-synthesized MTβ and CM-3 toxins on nine subtypes of muscarinic and adrenergic receptors and demonstrate their high potency for α-adrenoceptors and in particular a sub-nanomolar affinity for the α1A-subtype. Strikingly, no or very weak affinity were found for muscarinic receptors, highlighting that pharmacological characterizations of venom-purified peptides may be risky due to possible contaminations. The biological profile of these two homologous toxins looks like that one previously reported for the Dendroaspis angusticeps ρ-Da1a toxin. Nevertheless, MTβ and CM-3 interact more potently than ρ-Da1a with α1B- and α1D-AR subtypes. A computational analysis of the stability of the MTβ structure suggests that mutation S38I, could be involved in this gain in function.
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Affiliation(s)
- Guillaume Blanchet
- CEA, iBiTec-S, Service d'Ingénierie Moléculaire des Protéines (SIMOPRO), F-91191 Gif sur Yvette, France; UFR Sciences de la Vie, Université Pierre et Marie Curie (UPMC), 4 place Jussieu, Paris, France
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Quinton L, Servent D, Girard E, Molgó J, Le Caer JP, Malosse C, Haidar EA, Lecoq A, Gilles N, Chamot-Rooke J. Identification and functional characterization of a novel α-conotoxin (EIIA) from Conus ermineus. Anal Bioanal Chem 2013; 405:5341-51. [PMID: 23584713 DOI: 10.1007/s00216-013-6926-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 03/14/2013] [Accepted: 03/18/2013] [Indexed: 01/22/2023]
Abstract
Nicotinic acetylcholine receptors (nAChRs) are one of the most important families in the ligand-gated ion channel superfamily due to their involvement in primordial brain functions and in several neurodegenerative pathologies. The discovery of new ligands which can bind with high affinity and selectivity to nAChR subtypes is of prime interest in order to study these receptors and to potentially discover new drugs for treating various pathologies. Predatory cone snails of the genus Conus hunt their prey using venoms containing a large number of small, highly structured peptides called conotoxins. Conotoxins are classified in different structural families and target a large panel of receptors and ion channels. Interestingly, nAChRs represent the only subgroup for which Conus has developed seven distinct families of conotoxins. Conus venoms have thus received much attention as they could represent a potential source of selective ligands of nAChR subtypes. We describe the mass spectrometric-based approaches which led to the discovery of a novel α-conotoxin targeting muscular nAChR from the venom of Conus ermineus. The presence of several posttranslational modifications complicated the N-terminal sequencing. To discriminate between the different possible sequences, analogs with variable N-terminus were synthesized and fragmented by MS/MS. Understanding the fragmentation pathways in the low m/z range appeared crucial to determine the right sequence. The biological activity of this novel α-conotoxin (α-EIIA) that belongs to the unusual α4/4 subfamily was determined by binding experiments. The results revealed not only its selectivity for the muscular nAChR, but also a clear discrimination between the two binding sites described for this receptor.
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Affiliation(s)
- Loïc Quinton
- Laboratoire des Mécanismes Réactionnels, Département de Chimie, Ecole Polytechnique, CNRS UMR7651, 91128 Palaiseau Cedex, France
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Girish VM, Kumar S, Joseph L, Jobichen C, Kini RM, Sivaraman J. Identification and structural characterization of a new three-finger toxin hemachatoxin from Hemachatus haemachatus venom. PLoS One 2012; 7:e48112. [PMID: 23144733 PMCID: PMC3483290 DOI: 10.1371/journal.pone.0048112] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2012] [Accepted: 09/19/2012] [Indexed: 01/26/2023] Open
Abstract
Snake venoms are rich sources of biologically active proteins and polypeptides. Three-finger toxins are non-enzymatic proteins present in elapid (cobras, kraits, mambas and sea snakes) and colubrid venoms. These proteins contain four conserved disulfide bonds in the core to maintain the three-finger folds. Although all three-finger toxins have similar fold, their biological activities are different. A new three-finger toxin (hemachatoxin) was isolated from Hemachatus haemachatus (Ringhals cobra) venom. Its amino acid sequence was elucidated, and crystal structure was determined at 2.43 Å resolution. The overall fold is similar to other three-finger toxins. The structure and sequence analysis revealed that the fold is maintained by four highly conserved disulfide bonds. It exhibited highest similarity to particularly P-type cardiotoxins that are known to associate and perturb the membrane surface with their lipid binding sites. Also, the increased B value of hemachotoxin loop II suggests that loop II is flexible and may remain flexible until its interaction with membrane phospholipids. Based on the analysis, we predict hemachatoxin to be cardiotoxic/cytotoxic and our future experiments will be directed to characterize the activity of hemachatoxin.
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Affiliation(s)
| | - Sundramurthy Kumar
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, Singapore
| | - Lissa Joseph
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, Singapore
| | - Chacko Jobichen
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, Singapore
| | - R. Manjunatha Kini
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, Singapore
- Department of Biochemistry, Medical College of Virginia, Virginia Commonwealth University, Richmond, Virginia, United States of America
- * E-mail: (RMK); (JS)
| | - J. Sivaraman
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, Singapore
- * E-mail: (RMK); (JS)
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Abstract
Three-finger toxins (TFTs) are the main venom components of snakes from Elapidae family. Amino acid sequences of more than five hundreds TFTs are determined; these toxins form one of the largest protein families present in snake venoms. The first TFT α-bungarotoxin was isolated almost half a century ago and so far it remains a valuable tool in the study of nicotinic acetylcholine receptors. TFTs possess diverse biological activities; for example, α-neurotoxins bind specifically with high affinity to nicotinic acetylcholine receptors, while cytotoxins induce non-specific lysis in great variety of cells. These toxins are widely used as instruments in different branches of life sciences. In this review the main landmarks in TFT study are considered. These are the discovery and isolation of TFTs, determination of their structure and mode of action as well as evolution and relationship within the family.
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Affiliation(s)
- Yuri N Utkin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, RAS, ul. Miklukho-Maklaya 16/10, Moscow 117997, Russia.
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Zhang Y, Xu J, Wang Z, Zhang X, Liang X, Civelli O. BmK-YA, an enkephalin-like peptide in scorpion venom. PLoS One 2012; 7:e40417. [PMID: 22792309 PMCID: PMC3392217 DOI: 10.1371/journal.pone.0040417] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 06/07/2012] [Indexed: 11/18/2022] Open
Abstract
By screening extracts of venom from the Asian scorpion Buthus martensii Karsch (BmK) for their abilities to activate opioid receptors, we have identified BmK-YA, an amidated peptide containing an enkephalin-like sequence. BmK-YA is encoded by a precursor that displays a signal sequence and contains four copies of BmK-YA sequences and four of His4-BmK-YA, all flanked by single amino acid residues. BmK-YA and His4-BmK-YA are amidated and thus fulfill the characteristics expected of bioactive peptides. BmK-YA can activate mammalian opioid receptors with selectivity for the δ subtype while His4-BmK-YA is inactive at opioid receptors. The discovery of BmK-YA suggests that scorpion venom may represent a novel source of bioactive molecules targeting G protein-coupled receptors (GPCRs) and reveal additional insights on the evolution of the opioid precursors.
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Affiliation(s)
- Yan Zhang
- Department of Pharmacology, University of California Irvine, Irvine, California, United States of America
| | - Junyan Xu
- Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
| | - Zhiwei Wang
- Department of Pharmacology, University of California Irvine, Irvine, California, United States of America
| | - Xiuli Zhang
- Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
| | - Xinmiao Liang
- Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
- * E-mail: (XL); (OC)
| | - Olivier Civelli
- Department of Pharmacology, University of California Irvine, Irvine, California, United States of America
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, California, United States of America
- Department of Pharmaceutical Sciences, University of California Irvine, Irvine, California, United States of America
- * E-mail: (XL); (OC)
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Fruchart-Gaillard C, Mourier G, Blanchet G, Vera L, Gilles N, Ménez R, Marcon E, Stura EA, Servent D. Engineering of three-finger fold toxins creates ligands with original pharmacological profiles for muscarinic and adrenergic receptors. PLoS One 2012; 7:e39166. [PMID: 22720062 PMCID: PMC3375269 DOI: 10.1371/journal.pone.0039166] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 05/16/2012] [Indexed: 01/26/2023] Open
Abstract
Protein engineering approaches are often a combination of rational design and directed evolution using display technologies. Here, we test “loop grafting,” a rational design method, on three-finger fold proteins. These small reticulated proteins have exceptional affinity and specificity for their diverse molecular targets, display protease-resistance, and are highly stable and poorly immunogenic. The wealth of structural knowledge makes them good candidates for protein engineering of new functionality. Our goal is to enhance the efficacy of these mini-proteins by modifying their pharmacological properties in order to extend their use in imaging, diagnostics and therapeutic applications. Using the interaction of three-finger fold toxins with muscarinic and adrenergic receptors as a model, chimeric toxins have been engineered by substituting loops on toxin MT7 by those from toxin MT1. The pharmacological impact of these grafts was examined using binding experiments on muscarinic receptors M1 and M4 and on the α1A-adrenoceptor. Some of the designed chimeric proteins have impressive gain of function on certain receptor subtypes achieving an original selectivity profile with high affinity for muscarinic receptor M1 and α1A-adrenoceptor. Structure-function analysis supported by crystallographic data for MT1 and two chimeras permits a molecular based interpretation of these gains and details the merits of this protein engineering technique. The results obtained shed light on how loop permutation can be used to design new three-finger proteins with original pharmacological profiles.
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Affiliation(s)
- Carole Fruchart-Gaillard
- CEA, iBiTecS, Service d’Ingénierie Moléculaire des Protéines, Laboratoire de Toxinologie Moléculaire et Biotechnologies, Gif-sur-Yvette, France
| | - Gilles Mourier
- CEA, iBiTecS, Service d’Ingénierie Moléculaire des Protéines, Laboratoire de Toxinologie Moléculaire et Biotechnologies, Gif-sur-Yvette, France
| | - Guillaume Blanchet
- CEA, iBiTecS, Service d’Ingénierie Moléculaire des Protéines, Laboratoire de Toxinologie Moléculaire et Biotechnologies, Gif-sur-Yvette, France
- Université Pierre et Marie Curie, Paris, France
| | - Laura Vera
- CEA, iBiTecS, Service d’Ingénierie Moléculaire des Protéines, Laboratoire de Toxinologie Moléculaire et Biotechnologies, Gif-sur-Yvette, France
| | - Nicolas Gilles
- CEA, iBiTecS, Service d’Ingénierie Moléculaire des Protéines, Laboratoire de Toxinologie Moléculaire et Biotechnologies, Gif-sur-Yvette, France
| | - Renée Ménez
- CEA, iBiTecS, Service d’Ingénierie Moléculaire des Protéines, Laboratoire de Toxinologie Moléculaire et Biotechnologies, Gif-sur-Yvette, France
| | - Elodie Marcon
- CEA, iBiTecS, Service d’Ingénierie Moléculaire des Protéines, Laboratoire de Toxinologie Moléculaire et Biotechnologies, Gif-sur-Yvette, France
| | - Enrico A. Stura
- CEA, iBiTecS, Service d’Ingénierie Moléculaire des Protéines, Laboratoire de Toxinologie Moléculaire et Biotechnologies, Gif-sur-Yvette, France
| | - Denis Servent
- CEA, iBiTecS, Service d’Ingénierie Moléculaire des Protéines, Laboratoire de Toxinologie Moléculaire et Biotechnologies, Gif-sur-Yvette, France
- * E-mail:
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Characterization of α2B-adrenoceptor ligand binding in the presence of Muscarinic toxin α and delineation of structural features of receptor binding selectivity. Eur J Pharmacol 2012; 683:63-70. [DOI: 10.1016/j.ejphar.2012.03.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Revised: 03/09/2012] [Accepted: 03/09/2012] [Indexed: 11/24/2022]
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Näreoja K, Kukkonen JP, Rondinelli S, Toivola DM, Meriluoto J, Näsman J. Adrenoceptor activity of muscarinic toxins identified from mamba venoms. Br J Pharmacol 2012; 164:538-50. [PMID: 21557730 DOI: 10.1111/j.1476-5381.2011.01468.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Muscarinic toxins (MTs) are snake venom peptides named for their ability to interfere with ligand binding to muscarinic acetylcholine receptors (mAChRs). Recent data infer that these toxins may have other G-protein-coupled receptor targets than the mAChRs. The purpose of this study was to systematically investigate the interactions of MTs with the adrenoceptor family members. EXPERIMENTAL APPROACH We studied the interaction of four common MTs, MT1, MT3, MT7 and MTα, with cloned receptors expressed in insect cells by radioligand binding. Toxins showing modest to high-affinity interactions with adrenoceptors were additionally tested for effects on functional receptor responses by way of inhibition of agonist-induced Ca²⁺ increases. KEY RESULTS All MTs behaved non-competitively in radioligand displacement binding. MT1 displayed higher binding affinity for the human α(2B)-adrenoceptor (IC₅₀ = 2.3 nM) as compared with muscarinic receptors (IC₅₀ ≥ 100 nM). MT3 appeared to have a broad spectrum of targets showing high-affinity binding (IC₅₀ = 1-10 nM) to M₄ mAChR, α(1A)-, α(1D)- and α(2A)-adrenoceptors and lower affinity binding (IC₅₀ ≥ 25 nM) to α(1B)- and α(2C)-adrenoceptors and M₁ mAChR. MT7 did not detectably bind to other receptors than M₁, and MTα was specific for the α(2B)-adrenoceptor. None of the toxins showed effects on β₁- or β₂-adrenoceptors. CONCLUSIONS AND IMPLICATIONS Some of the MTs previously found to interact predominantly with mAChRs were shown to bind with high affinity to selected adrenoceptor subtypes. This renders these peptide toxins useful for engineering selective ligands to target various adrenoceptors.
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Affiliation(s)
- K Näreoja
- Department of Biosciences, Biochemistry, Åbo Akademi University, Turku, Finland
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Näreoja K, Näsman J. Selective targeting of G-protein-coupled receptor subtypes with venom peptides. Acta Physiol (Oxf) 2012; 204:186-201. [PMID: 21481193 DOI: 10.1111/j.1748-1716.2011.02305.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The G-protein-coupled receptor (GPCR) family is one of the largest gene superfamilies with approx. 370 members responding to endogenous ligands in humans and a roughly equal amount of receptors sensitive to external stimuli from the surrounding. A number of receptors from this superfamily are well recognized targets for medical treatment of various disease conditions, whereas for many others the potential medical benefit of interference is still obscure. A general problem associated with GPCR research and therapeutics is the insufficient specificity of available ligands to differentiate between closely homologous receptor subtypes. In this context, venom peptides could make a significant contribution to the development of more specific drugs. Venoms from certain animals specialized in biochemical hunting contain a mixture of molecules that are directed towards a variety of membrane proteins. Peptide toxins isolated from these mixtures usually exhibit high specificity for their targets. Muscarinic toxins found from mamba snakes attracted much attention during the 1990s. These are 65-66 amino acid long peptides with a structural three-finger folding similar to the α-neurotoxins and they target the muscarinic acetylcholine receptors in a subtype-selective manner. Recently, several members of the three-finger toxins from mamba snakes as well as conotoxins from marine cone snails have been shown to selectively interact with subtypes of adrenergic receptors. In this review, we will discuss the GPCR-directed peptide toxins found from different venoms and how some of these can be useful in exploring specific roles of receptor subtypes.
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Affiliation(s)
- K Näreoja
- Department of Biosciences, Biochemistry, Åbo Akademi University, Turku, Finland
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Näreoja K, Louhivuori LM, Akerman KEO, Meriluoto J, Näsman J. Glycosylphosphatidylinositol (GPI)-anchoring of mamba toxins enables cell-restricted receptor silencing. Biochem Biophys Res Commun 2011; 417:93-7. [PMID: 22138651 DOI: 10.1016/j.bbrc.2011.11.062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Accepted: 11/12/2011] [Indexed: 01/30/2023]
Abstract
Muscarinic toxins (MTs) are snake venom peptides found to selectively target specific subtypes of G-protein-coupled receptors. In here, we have attached a glycosylphosphatidylinositol (GPI) tail to three different toxin molecules and evaluated their receptor-blocking effects in a heterologous expression system. MT7-GPI remained anchored to the cell surface and selectively inhibited M(1) muscarinic receptor signaling expressed in the same cell. To further demonstrate the utility of the GPI tail, we generated MT3- and MTα-like gene sequences and fused these to the signal sequence for GPI attachment. Functional assessment of these membrane-anchored toxins on coexpressed target receptors indicated a prominent antagonistic effect. In ligand binding experiments the GPI-anchored toxins were found to exhibit similar selection profiles among receptor subtypes as the soluble toxins. The results indicate that GPI attachment of MTs and related receptor toxins could be used to assess the role of receptor subtypes in specific organs or even cells in vivo by transgenic approaches.
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Affiliation(s)
- Katja Näreoja
- Department of Biosciences, Biochemistry, Abo Akademi University, Turku, Finland
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Quinton L, Gilles N, Smargiasso N, Kiehne A, De Pauw E. An unusual family of glycosylated peptides isolated from Dendroaspis angusticeps venom and characterized by combination of collision induced and electron transfer dissociation. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2011; 22:1891-1897. [PMID: 21952754 DOI: 10.1007/s13361-011-0210-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 06/30/2011] [Accepted: 07/05/2011] [Indexed: 05/31/2023]
Abstract
This study describes the structural characterization of a totally new family of peptides from the venom of the snake green mamba (Dendroaspis angusticeps). Interestingly, these peptides differ in several points from other already known mamba toxins. First of all, they exhibit very small molecular masses, ranging from 1.3 to 2.4 kDa. The molecular mass of classical mamba toxins is in the range of 7 to 25 kDa. Second, the new peptides do not contain disulfide bonds, a post-translational modification commonly encountered in animal toxins. The third difference is the very high proportion of proline residues in the sequence accounting for about one-third of the sequence. Finally, these new peptides reveal a carbohydrate moiety, indicating a glycosylation in the sequence. The last two features have made the structural characterization of the new peptides by mass spectrometry a real analytical challenge. Peptides were characterized by a combined use of MALDI- TOF/TOF and nanoESI-IT-ETD experiments to determine not only the peptide sequence but also the composition and the position of the carbohydrate moiety. Anyway, such small glycosylated and proline-rich toxins are totally different from any other known snake peptide and form, as a consequence, a new family of peptides.
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Affiliation(s)
- Loïc Quinton
- Laboratoire de spectrométrie de masse, Département de Chimie-GIGA-R, Université de Liège, Liège 4000, Belgium.
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Rouget C, Quinton L, Maïga A, Gales C, Masuyer G, Malosse C, Chamot-Rooke J, Thai R, Mourier G, De Pauw E, Gilles N, Servent D. Identification of a novel snake peptide toxin displaying high affinity and antagonist behaviour for the α2-adrenoceptors. Br J Pharmacol 2011; 161:1361-74. [PMID: 20659106 DOI: 10.1111/j.1476-5381.2010.00966.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND AND PURPOSE Muscarinic and adrenergic G protein-coupled receptors (GPCRs) are the targets of rare peptide toxins isolated from snake or cone snail venoms. We used a screen to identify novel toxins from Dendroaspis angusticeps targeting aminergic GPCRs. These toxins may offer new candidates for the development of new tools and drugs. EXPERIMENTAL APPROACH In binding experiments with (3) H-rauwolscine, we studied the interactions of green mamba venom fractions with α(2) -adrenoceptors from rat brain synaptosomes. We isolated, sequenced and chemically synthesized a novel peptide, ρ-Da1b. This peptide was pharmacologically characterized using binding experiments and functional tests on human α(2)-adrenoceptors expressed in mammalian cells. KEY RESULTS ρ-Da1b, a 66-amino acid peptide stabilized by four disulphide bridges, belongs to the three-finger-fold peptide family. Its synthetic homologue inhibited 80% of (3) H-rauwolscine binding to the three α(2)-adrenoceptor subtypes, with an affinity between 14 and 73 nM and Hill slopes close to unity. Functional experiments on α(2A) -adrenoceptor demonstrated that ρ-Da1b is an antagonist, shifting adrenaline activation curves to the right. Schild regression revealed slopes of 0.97 and 0.67 and pA(2) values of 5.93 and 5.32 for yohimbine and ρ-Da1b, respectively. CONCLUSIONS AND IMPLICATIONS ρ-Da1b is the first toxin identified to specifically interact with α(2)-adrenoceptors, extending the list of class A GPCRs sensitive to toxins. Additionally, its affinity and atypical mode of interaction open up the possibility of its use as a new pharmacological tool, in the study of the physiological roles of α(2)-adrenoceptor subtypes.
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Affiliation(s)
- Céline Rouget
- CEA, iBiTec-S, Service d'Ingénierie Moléculaire des Protéines, Gif sur Yvette, France
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Servent D, Blanchet G, Mourier G, Marquer C, Marcon E, Fruchart-Gaillard C. Muscarinic toxins. Toxicon 2011; 58:455-63. [PMID: 21906611 DOI: 10.1016/j.toxicon.2011.08.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Revised: 07/12/2011] [Accepted: 08/08/2011] [Indexed: 12/15/2022]
Abstract
Muscarinic toxins isolated from the venom of Dendroaspis snakes may interact with a high affinity, large selectivity and various functional properties with muscarinic receptors. Therefore, these toxins are invaluable tools for studying the physiological role, molecular functioning and structural organization of the five subtypes of these G-Protein Coupled Receptors. We review the data on the most relevant results dealing with the isolation/identification, mode of action, structure/function and exploitation of these toxins and finally highlight the unresolved issues related to their pharmacological studies.
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Affiliation(s)
- Denis Servent
- CEA, Institute of Biology and Technology, Service d'Ingénierie Moléculaire des Protéines, Gif-sur-Yvette 91191, France.
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Maïga A, Mourier G, Quinton L, Rouget C, Gales C, Denis C, Lluel P, Sénard JM, Palea S, Servent D, Gilles N. G protein-coupled receptors, an unexploited animal toxin targets: Exploration of green mamba venom for novel drug candidates active against adrenoceptors. Toxicon 2011; 59:487-96. [PMID: 21419153 DOI: 10.1016/j.toxicon.2011.03.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2010] [Revised: 03/02/2011] [Accepted: 03/08/2011] [Indexed: 02/07/2023]
Abstract
At a time when pharmaceutical companies are having trouble finding new low MW drugs and when biologics are becoming more common, animal venoms could constitute an underexploited source of novel drug candidates. We looked for identifying novel animal toxins active against G protein-coupled receptors (GPCR), the most frequently exploited class of treatment targets, with the aim to develop novel research tools and drug candidates. Screening of green mamba (Dendroaspis angusticeps) venom against adrenoceptors identified two novel venom peptides. ρ-Da1a shown an affinity of 0.35 nM for the α1a-AR while ρ-Da1b displayed affinities between 14 and 73 nM for the three α2-ARs. These two venom peptides have sequences similar to those of muscarinic toxins and belong to the three-finger-fold protein family. α1a-AR is the primary target for the treatment of prostate hypertrophy. In vitro and in vivo tests demonstrated that ρ-Da1a reduced prostatic muscle tone as efficiently as tamsulosin (an antagonist presently used), but with fewer cardiovascular side effects. α2-ARs are the prototype of GPCRs not currently used as treatment targets due to a lack of specific ligands. Blockage of these receptors increases intestinal motility, which may be compromised by abdominal surgery and reduces orthosteric hypotension. In vitro and in vivo tests demonstrated that ρ-Da1b antagonizes α2-ARs in smooth muscles and increased heart rate and blood catecholamine concentrations. These results highlight possible exploitation of ρ-Da1a and ρ-Da1b in important pathologies.
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Affiliation(s)
- Arhamatoulaye Maïga
- CEA, iBiTec-S, Service d'Ingénierie Moléculaire des Protéines (SIMOPRO), F-91191 Gif sur Yvette, France
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Conceição K, Bruni FM, Santos JM, Lopes RM, Marques EE, Fernandez JH, Lopes-Ferreira M. The action of fish peptide Orpotrin analogs on microcirculation. J Pept Sci 2011; 17:192-9. [PMID: 21308875 DOI: 10.1002/psc.1311] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 08/30/2010] [Accepted: 09/10/2010] [Indexed: 11/12/2022]
Abstract
In order to investigate the relationship between the primary structure of Orpotrin, a vasoactive peptide previously isolated from the freshwater stingray Potamotrygon gr. orbignyi, and its microcirculatory effects, three Orpotrin analogs were synthesized. The analogs have a truncated N-terminal with a His residue deletion and two substituted amino acid residues, where one Nle is substituted for one internal Lys residue and the third analog has a substitution of a Pro for an Ala (Orp-desH(1) , Orp-Nle and Orp-Pro/Ala, respectively). Only Orp-desH(1) could induce a lower vasoconstriction effect compared with the natural Orpotrin, indicating that besides the N-terminal, the positive charge of Lys and the Pro residues located at the center of the amino acid chain is crucial for this vasoconstriction effect. Importantly, the suggestions made with bioactive peptides were based on the molecular modeling and dynamics of peptides, the presence of key amino acids and shared activity in microcirculation, characterized by intravital microscopy. Moreover, this study has demonstrated that even subtle changes in the primary structure of Orpotrin alter the biological effects of this native peptide significantly, which could be of interest for biotechnological applications.
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Affiliation(s)
- Katia Conceição
- LETA (Laboratório Especial de Toxinologia Aplicada) Center for Applied Toxinology (CAT/CEPID), Butantan Institute, São Paulo, SP, Brazil
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Ciolek J, Maïga A, Marcon E, Servent D, Gilles N. Pharmacological characterization of zinc and copper interaction with the human alpha(1A)-adrenoceptor. Eur J Pharmacol 2011; 655:1-8. [PMID: 21262225 DOI: 10.1016/j.ejphar.2010.12.042] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Revised: 11/22/2010] [Accepted: 12/15/2010] [Indexed: 01/01/2023]
Abstract
Metal ions have a major role in human health, and interact with many classes of receptors including the G-protein coupled receptors. In the peripheral system, zinc mainly accumulates in the soft prostate organ and, with copper, influences prostate disease progression, from normal to hypertrophic or cancerous states. The development of these pathologies may be influenced by the α(1A)-adrenoceptor, the principal regulator of prostate tonicity. There is currently no information on possible interactions between metals and the α(1A)-adrenoceptor. We therefore studied the effects of several mono- and divalent ions on this receptor subtype using binding and functional experiments performed on expressed cloned human α(1A)-adrenoceptor. Regardless of the counter anion used, Zn(2+) and Cu(2+) interact with α(1A)-adrenoceptor with apparent affinities in the low micromolar range. In addition, using specific binding experiments, we established that these ions acted as negative allosteric ligands on prazosin/α(1A)-adrenoceptor interaction, but in a different manner from the allosteric modulator 5-(N-ethyl-N-isopropyl)-amiloride, suggesting distinct mode of interaction. In addition, the presence of Cu(2+) weakly decreased epinephrine affinity, whereas the addition of Zn(2+) shifted to the left the epinephrine binding curve, revealing a positive allosteric effect but only on half of the binding site. Finally, cell-based functional experiments demonstrated that Zn(2+) and Cu(2+) antagonized epinephrine activation in an insurmountable manner, by reducing agonist efficacy without any shift in the epinephrine activation curves. This study shows the interactions between metal ions and the α(1A)-adrenoceptor with affinities compatible with physiological concentrations and suggests that zinc and copper may have a biological role in prostate function.
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Affiliation(s)
- Justyna Ciolek
- CEA Saclay, iBiTec-S, SIMOPRO, 91191 Gif sur Yvette, France
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Koivula K, Rondinelli S, Näsman J. The three-finger toxin MTalpha is a selective alpha(2B)-adrenoceptor antagonist. Toxicon 2010; 56:440-7. [PMID: 20466015 DOI: 10.1016/j.toxicon.2010.05.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Revised: 04/14/2010] [Accepted: 05/04/2010] [Indexed: 12/16/2022]
Abstract
Muscarinic toxins (MTs) are three-finger folded peptides isolated from mamba snake venoms. In this report we describe a selective antagonistic interaction of MTalpha with the human alpha(2B)-adrenoceptor. In a functional assay, measuring the alpha(2B)-adrenoceptor-induced increase in intracellular [Ca(2+)], we found that both venomous MTalpha and synthetic MTalpha inhibited the response in a concentration-dependent way. MTalpha did not affect the responses of alpha(2A)-, alpha(2C)-, alpha(1A)- or alpha(1B)-adrenoceptors. To further explore the binding of MTalpha to the alpha(2B)-adrenoceptor, we performed ligand binding experiments on Sf9 cell homogenates with [(3)H]RX821002 as reporter ligand. MTalpha bound to the receptor rather slowly requiring about 60 min to reach equilibrium. In equilibrium binding experiments, MTalpha displaced the radioligand with an IC(50) of 3.2 nM, but was not able to displace all bound radioligand. Using a saturation binding protocol, we found that MTalpha suppressed the maximum binding without any greater impact on the affinity of the radioligand, indicating a non-competitive mode of inhibition. The toxin bound reversibly to alpha(2B)-adrenoceptor, but extensive washing was needed for full recovery of binding sites at high toxin concentrations. Surprisingly, MTalpha did not affect [(3)H]-N-methylscopolamine binding to the muscarinic receptor subtypes at concentrations found to fully block alpha(2B)-adrenoceptors, showing that the toxin is a more potent antagonist for the alpha(2B)-adrenoceptor than for muscarinic receptors. These findings should open up new views in terms of selective adrenoceptor drug design as well as in elucidation of alpha(2)-adrenoceptor physiology.
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Affiliation(s)
- Katja Koivula
- Department of Biochemistry and Pharmacy, Abo Akademi University, Tykistökatu 6, FIN-20520 Turku, Finland
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