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Qin C, Yang X, Zuo Z, Yuan P, Sun F, Luo X, Ye X, Cao Z, Chen Z, Wu Y. Differential potassium channel inhibitory activities of a novel thermostable degradation peptide BmKcug1a-P1 from scorpion medicinal material and its N-terminal truncated/restored peptides. Sci Rep 2024; 14:16092. [PMID: 38997408 PMCID: PMC11245557 DOI: 10.1038/s41598-024-66794-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Accepted: 07/03/2024] [Indexed: 07/14/2024] Open
Abstract
Thermally stable full-length scorpion toxin peptides and partially degraded peptides with complete disulfide bond pairing are valuable natural peptide resources in traditional Chinese scorpion medicinal material. However, their pharmacological activities are largely unknown. This study discovered BmKcug1a-P1, a novel N-terminal degraded peptide, in this medicinal material. BmKcug1a-P1 inhibited hKv1.2 and hKv1.3 potassium channels with IC50 values of 2.12 ± 0.27 μM and 1.54 ± 0.28 μM, respectively. To investigate the influence of N-terminal amino acid loss on the potassium channel inhibiting activities, three analogs (i.e., full-length BmKcug1a, BmKcug1a-P1-D2 and BmKcug1a-P1-D4) of BmKcug1a-P1 were prepared, and their potassium channel inhibiting activities on hKv1.3 channel were verified by whole-cell patch clamp technique. Interestingly, the potassium channel inhibiting activity of full-length BmKcug1a on the hKv1.3 channel was significantly improved compared to its N-terminal degraded form (BmKcug1a-P1), while the activities of two truncated analogs (i.e., BmKcug1a-P1-D2 and BmKcug1a-P1-D4) were similar to that of BmKcug1a-P1. Extensive alanine-scanning experiments identified the bonding interface (including two key functional residues, Asn30 and Arg34) of BmKcug1a-P1. Structural and functional dissection further elucidated whether N-terminal residues of the peptide are located at the bonding interface is important in determining whether the N-terminus significantly influences the potassium channel inhibiting activity of the peptide. Altogether, this research identified a novel N-terminal degraded active peptide, BmKcug1a-P1, from traditional Chinese scorpion medicinal material and elucidated how the N-terminus of peptides influences their potassium channel inhibiting activity, contributing to the functional identification and molecular truncation optimization of full-length and degraded peptides from traditional Chinese scorpion medicinal material Buthus martensii Karsch.
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Affiliation(s)
- Chenhu Qin
- Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hubei University of Medicine, Shiyan, 442000, China
- College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Xuhua Yang
- College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Zheng Zuo
- College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Peixin Yuan
- College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Fang Sun
- Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hubei University of Medicine, Shiyan, 442000, China
- College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Xudong Luo
- Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hubei University of Medicine, Shiyan, 442000, China
| | - Xiangdong Ye
- Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hubei University of Medicine, Shiyan, 442000, China
| | - Zhijian Cao
- College of Life Sciences, Wuhan University, Wuhan, 430072, China
- Center for BioDrug Research, Wuhan University, Wuhan, 430072, China
| | - Zongyun Chen
- Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hubei University of Medicine, Shiyan, 442000, China.
- College of Life Sciences, Wuhan University, Wuhan, 430072, China.
| | - Yingliang Wu
- College of Life Sciences, Wuhan University, Wuhan, 430072, China.
- Center for BioDrug Research, Wuhan University, Wuhan, 430072, China.
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Zavarzina II, Kuzmenkov AI, Dobrokhotov NA, Maleeva EE, Korolkova YV, Peigneur S, Tytgat J, Krylov NA, Vassilevski AA, Chugunov AO. The scorpion toxin BeKm-1 blocks hERG cardiac potassium channels using an indispensable arginine residue. FEBS Lett 2024; 598:889-901. [PMID: 38563123 DOI: 10.1002/1873-3468.14850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 02/07/2024] [Accepted: 02/20/2024] [Indexed: 04/04/2024]
Abstract
BeKm-1 is a peptide toxin from scorpion venom that blocks the pore of the potassium channel hERG (Kv11.1) in the human heart. Although individual protein structures have been resolved, the structure of the complex between hERG and BeKm-1 is unknown. Here, we used molecular dynamics and ensemble docking, guided by previous double-mutant cycle analysis data, to obtain an in silico model of the hERG-BeKm-1 complex. Adding to the previous mutagenesis study of BeKm-1, our model uncovers the key role of residue Arg20, which forms three interactions (a salt bridge and hydrogen bonds) with the channel vestibule simultaneously. Replacement of this residue even by lysine weakens the interactions significantly. In accordance, the recombinantly produced BeKm-1R20K mutant exhibited dramatically decreased activity on hERG. Our model may be useful for future drug design attempts.
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Affiliation(s)
- Iana I Zavarzina
- Moscow Institute of Physics and Technology (State University), Dolgoprudny, Russia
| | | | - Nikita A Dobrokhotov
- Moscow Institute of Physics and Technology (State University), Dolgoprudny, Russia
| | | | | | | | - Jan Tytgat
- Toxicology and Pharmacology, KU Leuven, Belgium
| | - Nikolay A Krylov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia
| | - Alexander A Vassilevski
- Moscow Institute of Physics and Technology (State University), Dolgoprudny, Russia
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia
| | - Anton O Chugunov
- Moscow Institute of Physics and Technology (State University), Dolgoprudny, Russia
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia
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Maatoug S, Cheikh A, Khamessi O, Tabka H, Landoulsi Z, Guigonis JM, Diochot S, Bendahhou S, Benkhalifa R. Cross Pharmacological, Biochemical and Computational Studies of a Human Kv3.1b Inhibitor from Androctonus australis Venom. Int J Mol Sci 2021; 22:ijms222212290. [PMID: 34830172 PMCID: PMC8618407 DOI: 10.3390/ijms222212290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 11/05/2021] [Accepted: 11/11/2021] [Indexed: 11/23/2022] Open
Abstract
The voltage-gated K+ channels Kv3.1 display fast activation and deactivation kinetics and are known to have a crucial contribution to the fast-spiking phenotype of certain neurons. AahG50, as a natural product extracted from Androctonus australis hector venom, inhibits selectively Kv3.1 channels. In the present study, we focused on the biochemical and pharmacological characterization of the component in AahG50 scorpion venom that potently and selectively blocks the Kv3.1 channels. We used a combined optimization through advanced biochemical purification and patch-clamp screening steps to characterize the peptide in AahG50 active on Kv3.1 channels. We described the inhibitory effect of a toxin on Kv3.1 unitary current in black lipid bilayers. In silico, docking experiments are used to study the molecular details of the binding. We identified the first scorpion venom peptide inhibiting Kv3.1 current at 170 nM. This toxin is the alpha-KTx 15.1, which occludes the Kv3.1 channel pore by means of the lysine 27 lateral chain. This study highlights, for the first time, the modulation of the Kv3.1 by alpha-KTx 15.1, which could be an interesting starting compound for developing therapeutic biomolecules against Kv3.1-associated diseases.
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Affiliation(s)
- Sonia Maatoug
- Laboratoire Biomolécules, Venins et Applications Théranostiques (LR20IPT01), Institut Pasteur de Tunis, Université Tunis El Manar, 13 Place Pasteur BP74, Tunis 1002, Tunisia; (A.C.); (H.T.); (Z.L.)
- Correspondence: (S.M.); (R.B.); Tel.: +216-98-81-27-32 (R.B.)
| | - Amani Cheikh
- Laboratoire Biomolécules, Venins et Applications Théranostiques (LR20IPT01), Institut Pasteur de Tunis, Université Tunis El Manar, 13 Place Pasteur BP74, Tunis 1002, Tunisia; (A.C.); (H.T.); (Z.L.)
| | - Oussema Khamessi
- Laboratoire des Biomolécules Thérapeutiques, Institut Pasteur de Tunis, Université de Tunis El Manar, 13 Place Pasteur BP74, Tunis 1002, Tunisia;
| | - Hager Tabka
- Laboratoire Biomolécules, Venins et Applications Théranostiques (LR20IPT01), Institut Pasteur de Tunis, Université Tunis El Manar, 13 Place Pasteur BP74, Tunis 1002, Tunisia; (A.C.); (H.T.); (Z.L.)
- Faculté des Sciences de Bizerte, Université de Carthage, Bizerte 7021, Tunisia
| | - Zied Landoulsi
- Laboratoire Biomolécules, Venins et Applications Théranostiques (LR20IPT01), Institut Pasteur de Tunis, Université Tunis El Manar, 13 Place Pasteur BP74, Tunis 1002, Tunisia; (A.C.); (H.T.); (Z.L.)
| | - Jean-Marie Guigonis
- Laboratory Transporter in Imaging and Radiotherapy in Oncology (TIRO), Direction de la Recherche Fondamentale (DRF), Institut des Sciences du Vivant Fréderic Joliot, Commissariat à l′Energie Atomique et aux Énergies Alternatives (CEA), Université Côte d’Azur, F-06107 Nice, France;
| | - Sylvie Diochot
- Institut de Pharmacologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, Université Côte d’Azur, 660 Route des Lucioles, Sophia-Antipolis, 06560 Valbonne, France;
| | - Saïd Bendahhou
- UMR7370 CNRS, LP2M, Université Côte d’Azur, Labex ICST, Nice, France;
| | - Rym Benkhalifa
- Laboratoire Biomolécules, Venins et Applications Théranostiques (LR20IPT01), Institut Pasteur de Tunis, Université Tunis El Manar, 13 Place Pasteur BP74, Tunis 1002, Tunisia; (A.C.); (H.T.); (Z.L.)
- Correspondence: (S.M.); (R.B.); Tel.: +216-98-81-27-32 (R.B.)
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Zhu W, Gao H, Luo X, Ye X, Ding L, Hao J, Shu Z, Li S, Li J, Chen Z. Cloning and identification of a new multifunctional Ascaris-type peptide from the hemolymph of Buthus martensii Karsch. Toxicon 2020; 184:167-174. [PMID: 32565098 DOI: 10.1016/j.toxicon.2020.06.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 06/10/2020] [Accepted: 06/15/2020] [Indexed: 10/24/2022]
Abstract
Only a few work have been done for peptides from non-venom gland tissues of venomous animals. Here, with the help of the whole body transcriptomic and the hemolymph proteomic data of the Chinese scorpion Buthus martensii Karsch, we identified the first Ascaris-type peptide BmHDP from scorpion hemolymph. The precursor of BmHDP has 80 residues, including a 16 residue signal peptide and a 64 residue mature peptide. The mature peptide has 10 conserved cysteines and adopts a conserved Ascaris-type fold. Using combined inclusion body refolding and biochemical identification strategies, recombinant BmHDP was obtained successfully. Protease inhibitory assays showed that BmHDP inhibited chymotrypsin apparently at a concentration of 8 nM. Patch-clamp experiments showed that BmHDP inhibited the Kv1.3 potassium channel apparently at a concentration of 1000 nM. Coagulation experiment assays showed that BmHDP inhibited intrinsic coagulation pathway apparently at a concentration of 500 nM. To the best of our knowledge, BmHDP is the first Ascaris-type peptide from scorpion hemolymph. Our work highlighted a functional link between scorpion non-venom gland peptides and venom gland toxin peptides, and suggested that scorpion hemolymph might be a new source of bioactive peptides.
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Affiliation(s)
- Wen Zhu
- Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, College of Basic Medicine, Hubei University of Medicine, Hubei, China
| | - Huanhuan Gao
- Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, College of Basic Medicine, Hubei University of Medicine, Hubei, China
| | - Xudong Luo
- Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, College of Basic Medicine, Hubei University of Medicine, Hubei, China; Institute of Biomedicine and Hubei Key Laboratory of Wudang Local Chinese Medicine Research, Hubei University of Medicine, Hubei, China
| | - Xiangdong Ye
- Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, College of Basic Medicine, Hubei University of Medicine, Hubei, China; Institute of Biomedicine and Hubei Key Laboratory of Wudang Local Chinese Medicine Research, Hubei University of Medicine, Hubei, China
| | - Li Ding
- Department of Clinical Laboratory, Dongfeng Hospital, Hubei University of Medicine, Hubei, China; Institute of Biomedicine and Hubei Key Laboratory of Wudang Local Chinese Medicine Research, Hubei University of Medicine, Hubei, China
| | - Jinbo Hao
- Department of Clinical Laboratory, Shiyan Occupational Disease Hospital, Hubei, China
| | - Zhan Shu
- Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, College of Basic Medicine, Hubei University of Medicine, Hubei, China
| | - Shan Li
- Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, College of Basic Medicine, Hubei University of Medicine, Hubei, China
| | - Jian Li
- Department of Human Parasitology, College of Basic Medical Sciences, Hubei University of Medicine, Hubei, China
| | - Zongyun Chen
- Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, College of Basic Medicine, Hubei University of Medicine, Hubei, China; Institute of Biomedicine and Hubei Key Laboratory of Wudang Local Chinese Medicine Research, Hubei University of Medicine, Hubei, China.
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Park BG, Peigneur S, Esaki N, Yamaguchi Y, Ryu JH, Tytgat J, Kim JI, Sato K. Solution Structure and Functional Analysis of HelaTx1: The First Toxin Member of the κ-KTx5 Subfamily. BMB Rep 2020. [PMID: 32172732 PMCID: PMC7262511 DOI: 10.5483/bmbrep.2020.53.5.256] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Scorpion venom comprises a cocktail of toxins that have proven to be useful molecular tools for studying the pharmacological properties of membrane ion channels. HelaTx1, a short peptide neurotoxin isolated recently from the venom of the scorpion Heterometrus laoticus, is a 25 amino acid peptide with two disulfide bonds that shares low sequence homology with other scorpion toxins. HelaTx1 effectively decreases the amplitude of the K+ currents of voltage-gated Kv1.1 and Kv1.6 channels expressed in Xenopus oocytes, and was identified as the first toxin member of the κ-KTx5 subfamily, based on a sequence comparison and phylogenetic analysis. In the present study, we report the NMR solution structure of HelaTx1, and the major interaction points for its binding to voltage-gated Kv1.1 channels. The NMR results indicate that HelaTx1 adopts a helix-loop-helix fold linked by two disulfide bonds without any β-sheets, resembling the molecular folding of other cysteine-stabilized helix-loop-helix (Cs α/α) scorpion toxins such as κ-hefutoxin, HeTx, and OmTx, as well as conotoxin pl14a. A series of alanine-scanning analogs revealed a broad surface on the toxin molecule largely comprising positively-charged residues that is crucial for interaction with voltage- gated Kv1.1 channels. Interestingly, the functional dyad, a key molecular determinant for activity against voltage-gated potassium channels in other toxins, is not present in HelaTx1.
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Affiliation(s)
- Bong Gyu Park
- Department of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| | - Steve Peigneur
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg, O&N2, P.O. Box 922, Leuven 3000, Belgium
| | - Nao Esaki
- Department of Environmental Sciences, Fukuoka Women’s University, Fukuoka 813-8529, Japan
| | - Yoko Yamaguchi
- Department of Environmental Sciences, Fukuoka Women’s University, Fukuoka 813-8529, Japan
| | - Jae Ha Ryu
- Department of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| | - Jan Tytgat
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg, O&N2, P.O. Box 922, Leuven 3000, Belgium
| | - Jae Il Kim
- Department of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| | - Kazuki Sato
- Department of Environmental Sciences, Fukuoka Women’s University, Fukuoka 813-8529, Japan
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6
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Aissaoui D, Mlayah-Bellalouna S, Jebali J, Abdelkafi-Koubaa Z, Souid S, Moslah W, Othman H, Luis J, ElAyeb M, Marrakchi N, Essafi-Benkhadir K, Srairi-Abid N. Functional role of Kv1.1 and Kv1.3 channels in the neoplastic progression steps of three cancer cell lines, elucidated by scorpion peptides. Int J Biol Macromol 2018; 111:1146-1155. [DOI: 10.1016/j.ijbiomac.2018.01.144] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 01/19/2018] [Accepted: 01/20/2018] [Indexed: 12/11/2022]
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7
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Deng Y, Gu J, Yan Z, Wang M, Ma C, Zhang J, Jiang G, Ge M, Xu S, Xu Z, Xiao L. De novo transcriptomic analysis of the venomous glands from the scorpion Heterometrus spinifer revealed unique and extremely high diversity of the venom peptides. Toxicon 2018; 143:1-19. [DOI: 10.1016/j.toxicon.2017.12.051] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 12/22/2017] [Accepted: 12/25/2017] [Indexed: 02/07/2023]
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8
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Jiménez-Vargas JM, Possani LD, Luna-Ramírez K. Arthropod toxins acting on neuronal potassium channels. Neuropharmacology 2017; 127:139-160. [PMID: 28941737 DOI: 10.1016/j.neuropharm.2017.09.025] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 09/13/2017] [Accepted: 09/15/2017] [Indexed: 01/01/2023]
Abstract
Arthropod venoms are a rich mixture of biologically active compounds exerting different physiological actions across diverse phyla and affecting multiple organ systems including the central nervous system. Venom compounds can inhibit or activate ion channels, receptors and transporters with high specificity and affinity providing essential insights into ion channel function. In this review, we focus on arthropod toxins (scorpions, spiders, bees and centipedes) acting on neuronal potassium channels. A brief description of the K+ channels classification and structure is included and a compendium of neuronal K+ channels and the arthropod toxins that modify them have been listed. This article is part of the Special Issue entitled 'Venom-derived Peptides as Pharmacological Tools.'
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Affiliation(s)
- Juana María Jiménez-Vargas
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad, 2001, Colonia Chamilpa, Apartado Postal 510-3, Cuernavaca 62210, Mexico
| | - Lourival D Possani
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad, 2001, Colonia Chamilpa, Apartado Postal 510-3, Cuernavaca 62210, Mexico
| | - Karen Luna-Ramírez
- Illawarra Health and Medical Research Institute, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia.
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Zhang S, Gao B, Zhu S. Independent Origins of Scorpion Toxins Affecting Potassium and Sodium Channels. EVOLUTION OF VENOMOUS ANIMALS AND THEIR TOXINS 2017. [DOI: 10.1007/978-94-007-6458-3_12] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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10
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Housley DM, Housley GD, Liddell MJ, Jennings EA. Scorpion toxin peptide action at the ion channel subunit level. Neuropharmacology 2016; 127:46-78. [PMID: 27729239 DOI: 10.1016/j.neuropharm.2016.10.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 09/06/2016] [Accepted: 10/06/2016] [Indexed: 12/19/2022]
Abstract
This review categorizes functionally validated actions of defined scorpion toxin (SCTX) neuropeptides across ion channel subclasses, highlighting key trends in this rapidly evolving field. Scorpion envenomation is a common event in many tropical and subtropical countries, with neuropharmacological actions, particularly autonomic nervous system modulation, causing significant mortality. The primary active agents within scorpion venoms are a diverse group of small neuropeptides that elicit specific potent actions across a wide range of ion channel classes. The identification and functional characterisation of these SCTX peptides has tremendous potential for development of novel pharmaceuticals that advance knowledge of ion channels and establish lead compounds for treatment of excitable tissue disorders. This review delineates the unique specificities of 320 individual SCTX peptides that collectively act on 41 ion channel subclasses. Thus the SCTX research field has significant translational implications for pathophysiology spanning neurotransmission, neurohumoral signalling, sensori-motor systems and excitation-contraction coupling. This article is part of the Special Issue entitled 'Venom-derived Peptides as Pharmacological Tools.'
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Affiliation(s)
- David M Housley
- College of Medicine and Dentistry, Cairns Campus, James Cook University, Cairns, Queensland 4878, Australia; Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia, Sydney, NSW 2052, Australia.
| | - Gary D Housley
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia, Sydney, NSW 2052, Australia
| | - Michael J Liddell
- Centre for Tropical Environmental and Sustainability Science and College of Science & Engineering, Cairns Campus, James Cook University, Cairns, Queensland 4878, Australia
| | - Ernest A Jennings
- College of Medicine and Dentistry, Cairns Campus, James Cook University, Cairns, Queensland 4878, Australia; Centre for Biodiscovery and Molecular Development of Therapeutics, James Cook University, Queensland 4878, Australia; Australian Institute of Tropical Health and Medicine, James Cook University, Cairns Campus, QLD, Australia
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Potassium channel blockers from the venom of the Brazilian scorpion Tityus serrulatus (). Toxicon 2016; 119:253-65. [PMID: 27349167 DOI: 10.1016/j.toxicon.2016.06.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 06/06/2016] [Accepted: 06/24/2016] [Indexed: 02/05/2023]
Abstract
Potassium (K(+)) channels are trans-membrane proteins, which play a key role in cellular excitability and signal transduction pathways. Scorpion toxins blocking the ion-conducting pore from the external side have been invaluable probes to elucidate the structural, functional, and physio-pathological characteristics of these ion channels. This review will focus on the interaction between K(+) channels and their peptide blockers isolated from the venom of the scorpion Tityus serrulatus, which is considered as the most dangerous scorpion in Brazil, in particular in Minas-Gerais State, where many casualties are described each year. The primary mechanisms of action of these K(+) blockers will be discussed in correlation with their structure, very often non-canonical compared to those of other well known K(+) channels blockers purified from other scorpion venoms. Also, special attention will be brought to the most recent data obtained by proteomic and transcriptomic analyses on Tityus serrulatus venoms and venom glands.
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Chen J, Zhang C, Yang W, Cao Z, Li W, Chen Z, Wu Y. SjAPI-2 is the first member of a new neurotoxin family with Ascaris-type fold and KCNQ1 inhibitory activity. Int J Biol Macromol 2015; 79:504-10. [DOI: 10.1016/j.ijbiomac.2015.05.027] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Revised: 05/09/2015] [Accepted: 05/12/2015] [Indexed: 01/12/2023]
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Electrophysiological characterization of Ts6 and Ts7, K⁺ channel toxins isolated through an improved Tityus serrulatus venom purification procedure. Toxins (Basel) 2014; 6:892-913. [PMID: 24590385 PMCID: PMC3968367 DOI: 10.3390/toxins6030892] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 01/24/2014] [Accepted: 02/17/2014] [Indexed: 01/09/2023] Open
Abstract
In Brazil, Tityus serrulatus (Ts) is the species responsible for most of the scorpion related accidents. Among the Ts toxins, the neurotoxins with action on potassium channels (α-KTx) present high interest, due to their effect in the envenoming process and the ion channel specificity they display. The α-KTx toxins family is the most relevant because its toxins can be used as therapeutic tools for specific target cells. The improved isolation method provided toxins with high resolution, obtaining pure Ts6 and Ts7 in two chromatographic steps. The effects of Ts6 and Ts7 toxins were evaluated in 14 different types of potassium channels using the voltage-clamp technique with two-microelectrodes. Ts6 toxin shows high affinity for Kv1.2, Kv1.3 and Shaker IR, blocking these channels in low concentrations. Moreover, Ts6 blocks the Kv1.3 channel in picomolar concentrations with an IC50 of 0.55 nM and therefore could be of valuable assistance to further designing immunosuppressive therapeutics. Ts7 toxin blocks multiple subtypes channels, showing low selectivity among the channels analyzed. This work also stands out in its attempt to elucidate the residues important for interacting with each channel and, in the near future, to model a desired drug.
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Hmed B, Serria HT, Mounir ZK. Scorpion peptides: potential use for new drug development. J Toxicol 2013; 2013:958797. [PMID: 23843786 PMCID: PMC3697785 DOI: 10.1155/2013/958797] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Revised: 05/19/2013] [Accepted: 05/20/2013] [Indexed: 12/13/2022] Open
Abstract
Several peptides contained in scorpion fluids showed diverse array of biological activities with high specificities to their targeted sites. Many investigations outlined their potent effects against microbes and showed their potential to modulate various biological mechanisms that are involved in immune, nervous, cardiovascular, and neoplastic diseases. Because of their important structural and functional diversity, it is projected that scorpion-derived peptides could be used to develop new specific drugs. This review summarizes relevant findings improving their use as valuable tools for new drugs development.
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Affiliation(s)
- BenNasr Hmed
- Laboratory of Pharmacology, Medicine Faculty of Sfax, Street of Majida Boulila, 3029 Sfax, Tunisia
| | - Hammami Turky Serria
- Laboratory of Pharmacology, Medicine Faculty of Sfax, Street of Majida Boulila, 3029 Sfax, Tunisia
| | - Zeghal Khaled Mounir
- Laboratory of Pharmacology, Medicine Faculty of Sfax, Street of Majida Boulila, 3029 Sfax, Tunisia
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15
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Xie S, Feng J, Yu C, Li Z, Wu Y, Cao Z, Li W, He X, Xiang M, Han S. Identification of a new specific Kv1.3 channel blocker, Ctri9577, from the scorpion Chaerilus tricostatus. Peptides 2012; 36:94-9. [PMID: 22580271 DOI: 10.1016/j.peptides.2012.04.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Revised: 04/26/2012] [Accepted: 04/26/2012] [Indexed: 01/04/2023]
Abstract
Scorpion toxins are valuable resources for discovering new ion channel modulators and drug candidates. Potassium channel Kv1.3 is an important pharmacological target of T cell-mediated autoimmune diseases, which are encouraging the screening and design of the specific peptide blockers for Kv1.3 channel. Ctri9577, the first neurotoxin gene of Chaerilidae family was cloned from the venom of the scorpion Chaerilus tricostatus through the constructing its cDNA library. The sequence analysis showed that the mature peptide of Ctri9577 contained 39 amino acid residues including six conserved cysteines, whose low sequence similarity indicated that it was a new member of α-KTx15 subfamily. By using expression and purification technology, the recombinant peptide was obtained. Subsequently, the electrophysiological experiments indicated that the Ctri9577 peptide selectively inhibited Kv1.3 channel current with an IC(50) of 0.49±0.45 nM without effectively blocking potassium channels Kv1.1, Kv1.2, hERG and SK3. All these findings not only enrich the knowledge of toxins from the Chaerilidae family, but also present a novel potential drug candidate targeting Kv1.3 channels for the therapy of autoimmune diseases.
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Affiliation(s)
- Shujun Xie
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, People's Republic of China
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16
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Truchet B, Manrique C, Sreng L, Chaillan FA, Roman FS, Mourre C. Kv4 potassium channels modulate hippocampal EPSP-spike potentiation and spatial memory in rats. Learn Mem 2012; 19:282-93. [PMID: 22700470 DOI: 10.1101/lm.025411.111] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Kv4 channels regulate the backpropagation of action potentials (b-AP) and have been implicated in the modulation of long-term potentiation (LTP). Here we showed that blockade of Kv4 channels by the scorpion toxin AmmTX3 impaired reference memory in a radial maze task. In vivo, AmmTX3 intracerebroventricular (i.c.v.) infusion increased and stabilized the EPSP-spike (E-S) component of LTP in the dentate gyrus (DG), with no effect on basal transmission or short-term plasticity. This increase in E-S potentiation duration could result from the combination of an increase in excitability of DG granular cells with a reduction of GABAergic inhibition, leading to a strong reduction of input specificity. Radioactive in situ hybridization (ISH) was used to evaluate the amounts of Kv4.2 and Kv4.3 mRNA in brain structures at different stages of a spatial learning task in naive, pseudoconditioned, and conditioned rats. Significant differences in Kv4.2 and Kv4.3 mRNA levels were observed between conditioned and pseudoconditioned rats. Kv4.2 and Kv4.3 mRNA levels were transiently up-regulated in the striatum, nucleus accumbens, retrosplenial, and cingulate cortices during early stages of learning, suggesting an involvement in the switch from egocentric to allocentric strategies. Spatial learning performance was positively correlated with the levels of Kv4.2 and Kv4.3 mRNAs in several of these brain structures. Altogether our findings suggest that Kv4 channels could increase the signal-to-noise ratio during information acquisition, thereby allowing a better encoding of the memory trace.
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Affiliation(s)
- Bruno Truchet
- Laboratory of Neuroscience and Cognition-LNC-UMR 7291, Centre National de la Recherche Scientifique-Aix-Marseille Université, Centre Saint-Charles, 13331 Marseille, France
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17
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Potassium Channels Blockers from the Venom of Androctonus mauretanicus mauretanicus. J Toxicol 2012; 2012:103608. [PMID: 22685457 PMCID: PMC3362950 DOI: 10.1155/2012/103608] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Accepted: 03/16/2012] [Indexed: 01/09/2023] Open
Abstract
K+ channels selectively transport K+ ions across cell membranes and play a key role in regulating the physiology of excitable and nonexcitable cells. Their activation allows the cell to repolarize after action potential firing and reduces excitability, whereas channel inhibition increases excitability. In eukaryotes, the pharmacology and pore topology of several structural classes of K+ channels have been well characterized in the past two decades. This information has come about through the extensive use of scorpion toxins. We have participated in the isolation and in the characterization of several structurally distinct families of scorpion toxin peptides exhibiting different K+ channel blocking functions. In particular, the venom from the Moroccan scorpion Androctonus mauretanicus mauretanicus provided several high-affinity blockers selective for diverse K+ channels (SKCa, Kv4.x, and Kv1.x K+ channel families). In this paper, we summarize our work on these toxin/channel interactions.
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18
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Jiménez-Vargas JM, Restano-Cassulini R, Possani LD. Toxin modulators and blockers of hERG K(+) channels. Toxicon 2012; 60:492-501. [PMID: 22497787 DOI: 10.1016/j.toxicon.2012.03.024] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Accepted: 03/27/2012] [Indexed: 12/24/2022]
Abstract
The K(+) channel encoded by the Ether-á-go-go-Related Gene (ERG) is expressed in different tissues of different animal species. There are at least three subtypes of this channel, being the sub-type 1 (ERG1) crucial in the repolarization phase of the cardiac action potential. Mutations in this gene can affect the properties of the channel producing the type II long QT syndrome (LQTS2) and many drugs are also known to affect this channel with a similar side effect. Various scorpion, spider and sea anemone toxins affect the ERG currents by blocking the ion-conducting pore from the external side or by modulating channel gating through binding to the voltage-sensor domain. By doing so, these toxins become very useful tools for better understanding the structural and functional characteristics of these ion channels. This review discusses the interaction between the ERG channels and the peptides isolated from venoms of these animals. Special emphasis is placed on scorpion toxins, although the effects of several spider venom toxins and anemone toxins will be also revised.
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Affiliation(s)
- J M Jiménez-Vargas
- Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico, Av. Universidad 2001, P.O. Box 501-3, Cuernavaca 62210, Mexico.
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19
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Interacting sites of scorpion toxin ErgTx1 with hERG1 K+ channels. Toxicon 2012; 59:633-41. [PMID: 22366117 DOI: 10.1016/j.toxicon.2012.02.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Revised: 01/12/2012] [Accepted: 02/02/2012] [Indexed: 11/23/2022]
Abstract
Peptides purified from scorpion venoms were shown to interact with specific amino acid residues present in the outer vestibule of various sub-types of potassium channels, occluding the pore and causing a decrement of K(+) permeability through the membrane of excitable and non excitable cells. This communication describes the identification of several interacting sites of toxin ErgTx1, a toxin purified from the venom of the scorpion Centruroides noxius, with the human ERG1 K(+) channels, by means of site-directed mutagenesis of specific residues of the toxin. Recombinant mutants of the gene coding for ErgTx1 were expressed heterologously in Escherichia coli, properly folded and their affinities and interactions with hERG1 channels were determined by patch-clamp techniques. Residues in position Y14, Y17 and F37 of the solvent exposed hydrophobic surface, and charged residues at the position K13 and K38 of ErgTx1 were shown to cause a decrement of the affinity from 20 folds to 3 orders of magnitude, thus suggesting that they are certainly participating on the binding surface of this toxin towards the hERG1 channels. Double mutants at positions K13 and F37, Y14 and F37, Y17 and F37 and K13 and K38 were also prepared and assayed, but the results obtained are not much different from the single point mutants of ErgTx1. The results of the present work indicate the most probable surface area of ErgTx1 that makes contact with the hERG channels.
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The potassium channel KcsA: a model protein in studying membrane protein oligomerization and stability of oligomeric assembly? Arch Biochem Biophys 2011; 510:1-10. [PMID: 21458409 DOI: 10.1016/j.abb.2011.03.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2010] [Revised: 03/25/2011] [Accepted: 03/25/2011] [Indexed: 01/01/2023]
Abstract
Many membrane proteins are functional as stable oligomers. An understanding of the conditions that elicit and enhance oligomerization is important in many therapeutics. In this regard, protein-protein and protein-lipid interactions play crucial roles in the assembly and stability of oligomeric complexes. Recent years have seen a rapid increase in the mechanistic information on the importance of cytoplasmic termini in determining subunit assembly and stability of oligomeric complexes. In addition, the role of specific protein-lipid interaction between anionic phospholipids and "hot spots" on the protein surface has also become evident in stabilizing oligomeric assemblies. This review focuses on several contemporary developments of membrane proteins that stabilize oligomers by taking the potassium channel KcsA as an exemplary ion channel.
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Fry BG, Roelants K, Champagne DE, Scheib H, Tyndall JD, King GF, Nevalainen TJ, Norman JA, Lewis RJ, Norton RS, Renjifo C, de la Vega RCR. The Toxicogenomic Multiverse: Convergent Recruitment of Proteins Into Animal Venoms. Annu Rev Genomics Hum Genet 2009; 10:483-511. [DOI: 10.1146/annurev.genom.9.081307.164356] [Citation(s) in RCA: 587] [Impact Index Per Article: 39.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Throughout evolution, numerous proteins have been convergently recruited into the venoms of various animals, including centipedes, cephalopods, cone snails, fish, insects (several independent venom systems), platypus, scorpions, shrews, spiders, toxicoferan reptiles (lizards and snakes), and sea anemones. The protein scaffolds utilized convergently have included AVIT/colipase/prokineticin, CAP, chitinase, cystatin, defensins, hyaluronidase, Kunitz, lectin, lipocalin, natriuretic peptide, peptidase S1, phospholipase A2, sphingomyelinase D, and SPRY. Many of these same venom protein types have also been convergently recruited for use in the hematophagous gland secretions of invertebrates (e.g., fleas, leeches, kissing bugs, mosquitoes, and ticks) and vertebrates (e.g., vampire bats). Here, we discuss a number of overarching structural, functional, and evolutionary generalities of the protein families from which these toxins have been frequently recruited and propose a revised and expanded working definition for venom. Given the large number of striking similarities between the protein compositions of conventional venoms and hematophagous secretions, we argue that the latter should also fall under the same definition.
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Affiliation(s)
- Bryan G. Fry
- Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Melbourne 3010 Australia
| | - Kim Roelants
- Unit of Ecology and Systematics, Vrije Universiteit Brussels, 1050 Brussels, Belgium
| | - Donald E. Champagne
- Department of Entomology and Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia 30602
| | | | - Joel D.A. Tyndall
- National School of Pharmacy, University of Otago, Dunedin 9054, New Zealand
| | - Glenn F. King
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
| | | | - Janette A. Norman
- Sciences Department, Museum Victoria, Melbourne, Victoria 3001, Australia
| | - Richard J. Lewis
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Raymond S. Norton
- The Walter and Eliza Hall Institute of Medical Research, Parkville 3050, Victoria, Australia
| | - Camila Renjifo
- Department of Physiological Sciences, Faculty of Medicine, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Ricardo C. Rodríguez de la Vega
- Structural and Computational Biology/Gene Expression Units, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
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