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Tsetlin V, Shelukhina I, Kozlov S, Kasheverov I. Fifty Years of Animal Toxin Research at the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS. Int J Mol Sci 2023; 24:13884. [PMID: 37762187 PMCID: PMC10530976 DOI: 10.3390/ijms241813884] [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: 08/18/2023] [Revised: 09/04/2023] [Accepted: 09/06/2023] [Indexed: 09/29/2023] Open
Abstract
This review covers briefly the work carried out at our institute (IBCh), in many cases in collaboration with other Russian and foreign laboratories, for the last 50 years. It discusses the discoveries and studies of various animal toxins, including protein and peptide neurotoxins acting on the nicotinic acetylcholine receptors (nAChRs) and on other ion channels. Among the achievements are the determination of the primary structures of the α-bungarotoxin-like three-finger toxins (TFTs), covalently bound dimeric TFTs, glycosylated cytotoxin, inhibitory cystine knot toxins (ICK), modular ICKs, and such giant molecules as latrotoxins and peptide neurotoxins from the snake, as well as from other animal venoms. For a number of toxins, spatial structures were determined, mostly by 1H-NMR spectroscopy. Using this method in combination with molecular modeling, the molecular mechanisms of the interactions of several toxins with lipid membranes were established. In more detail are presented the results of recent years, among which are the discovery of α-bungarotoxin analogs distinguishing the two binding sites in the muscle-type nAChR, long-chain α-neurotoxins interacting with α9α10 nAChRs and with GABA-A receptors, and the strong antiviral effects of dimeric phospholipases A2. A summary of the toxins obtained from arthropod venoms includes only highly cited works describing the molecules' success story, which is associated with IBCh. In marine animals, versatile toxins in terms of structure and molecular targets were discovered, and careful work on α-conotoxins differing in specificity for individual nAChR subtypes gave information about their binding sites.
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Affiliation(s)
- Victor Tsetlin
- Department of Molecular Neuroimmune Signaling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklay Str., 117997 Moscow, Russia; (I.S.); (I.K.)
| | - Irina Shelukhina
- Department of Molecular Neuroimmune Signaling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklay Str., 117997 Moscow, Russia; (I.S.); (I.K.)
| | - Sergey Kozlov
- Department of Molecular Neurobiology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklay Str., 117997 Moscow, Russia;
| | - Igor Kasheverov
- Department of Molecular Neuroimmune Signaling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklay Str., 117997 Moscow, Russia; (I.S.); (I.K.)
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Dubovskii PV, Ignatova AA, Alekseeva AS, Starkov VG, Boldyrev IA, Feofanov AV, Utkin YN. Membrane-Disrupting Activity of Cobra Cytotoxins Is Determined by Configuration of the N-Terminal Loop. Toxins (Basel) 2022; 15:6. [PMID: 36668826 PMCID: PMC9866941 DOI: 10.3390/toxins15010006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/15/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
In aqueous solutions, cobra cytotoxins (CTX), three-finger folded proteins, exhibit conformational equilibrium between conformers with either cis or trans peptide bonds in the N-terminal loop (loop-I). The equilibrium is shifted to the cis form in toxins with a pair of adjacent Pro residues in this loop. It is known that CTX with a single Pro residue in loop-I and a cis peptide bond do not interact with lipid membranes. Thus, if a cis peptide bond is present in loop-I, as in a Pro-Pro containing CTX, this should weaken its lipid interactions and likely cytotoxic activities. To test this, we have isolated seven CTX from Naja naja and N. haje cobra venoms. Antibacterial and cytotoxic activities of these CTX, as well as their capability to induce calcein leakage from phospholipid liposomes, were evaluated. We have found that CTX with a Pro-Pro peptide bond indeed exhibit attenuated membrane-perturbing activity in model membranes and lower cytotoxic/antibacterial activity compared to their counterparts with a single Pro residue in loop-I.
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Affiliation(s)
- Peter V. Dubovskii
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia
| | - Anastasia A. Ignatova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia
| | - Anna S. Alekseeva
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia
| | - Vladislav G. Starkov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia
| | - Ivan A. Boldyrev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia
| | - Alexey V. Feofanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia
- Bioengineering Department, Faculty of Biology, Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Yuri N. Utkin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia
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Dubovskii PV, Dubova KM, Bourenkov G, Starkov VG, Konshina AG, Efremov RG, Utkin YN, Samygina VR. Variability in the Spatial Structure of the Central Loop in Cobra Cytotoxins Revealed by X-ray Analysis and Molecular Modeling. Toxins (Basel) 2022; 14:toxins14020149. [PMID: 35202176 PMCID: PMC8880459 DOI: 10.3390/toxins14020149] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 02/05/2022] [Accepted: 02/16/2022] [Indexed: 02/04/2023] Open
Abstract
Cobra cytotoxins (CTs) belong to the three-fingered protein family and possess membrane activity. Here, we studied cytotoxin 13 from Naja naja cobra venom (CT13Nn). For the first time, a spatial model of CT13Nn with both “water” and “membrane” conformations of the central loop (loop-2) were determined by X-ray crystallography. The “water” conformation of the loop was frequently observed. It was similar to the structure of loop-2 of numerous CTs, determined by either NMR spectroscopy in aqueous solution, or the X-ray method. The “membrane” conformation is rare one and, to date has only been observed by NMR for a single cytotoxin 1 from N. oxiana (CT1No) in detergent micelle. Both CT13Nn and CT1No are S-type CTs. Membrane-binding of these CTs probably involves an additional step—the conformational transformation of the loop-2. To confirm this suggestion, we conducted molecular dynamics simulations of both CT1No and CT13Nn in the Highly Mimetic Membrane Model of palmitoiloleoylphosphatidylglycerol, starting with their “water” NMR models. We found that the both toxins transform their “water” conformation of loop-2 into the “membrane” one during the insertion process. This supports the hypothesis that the S-type CTs, unlike their P-type counterparts, require conformational adaptation of loop-2 during interaction with lipid membranes.
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Affiliation(s)
- Peter V. Dubovskii
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya str., 117997 Moscow, Russia; (V.G.S.); (A.G.K.); (R.G.E.); (Y.N.U.)
- Correspondence: or
| | - Kira M. Dubova
- FSRC “Crystallography and Photonics”, Russian Academy of Sciences, 111933 Moscow, Russia; (K.M.D.); (V.R.S.)
- NRC “Kurchatov Institute”, 123182 Moscow, Russia
| | - Gleb Bourenkov
- European Molecular Biology Laboratory, Hamburg Unit, c/o DESY, 22607 Hamburg, Germany;
| | - Vladislav G. Starkov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya str., 117997 Moscow, Russia; (V.G.S.); (A.G.K.); (R.G.E.); (Y.N.U.)
| | - Anastasia G. Konshina
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya str., 117997 Moscow, Russia; (V.G.S.); (A.G.K.); (R.G.E.); (Y.N.U.)
| | - Roman G. Efremov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya str., 117997 Moscow, Russia; (V.G.S.); (A.G.K.); (R.G.E.); (Y.N.U.)
- Moscow Institute of Physics and Technology (State University), 9 Institutskiy per., 141700 Dolgoprudny, Russia
- Higher School of Economics, National Research University, 20 Myasnitskaya str., 101000 Moscow, Russia
| | - Yuri N. Utkin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya str., 117997 Moscow, Russia; (V.G.S.); (A.G.K.); (R.G.E.); (Y.N.U.)
| | - Valeriya R. Samygina
- FSRC “Crystallography and Photonics”, Russian Academy of Sciences, 111933 Moscow, Russia; (K.M.D.); (V.R.S.)
- NRC “Kurchatov Institute”, 123182 Moscow, Russia
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Gutiérrez JM, Albulescu LO, Clare RH, Casewell NR, Abd El-Aziz TM, Escalante T, Rucavado A. The Search for Natural and Synthetic Inhibitors That Would Complement Antivenoms as Therapeutics for Snakebite Envenoming. Toxins (Basel) 2021; 13:451. [PMID: 34209691 PMCID: PMC8309910 DOI: 10.3390/toxins13070451] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 06/23/2021] [Accepted: 06/27/2021] [Indexed: 12/28/2022] Open
Abstract
A global strategy, under the coordination of the World Health Organization, is being unfolded to reduce the impact of snakebite envenoming. One of the pillars of this strategy is to ensure safe and effective treatments. The mainstay in the therapy of snakebite envenoming is the administration of animal-derived antivenoms. In addition, new therapeutic options are being explored, including recombinant antibodies and natural and synthetic toxin inhibitors. In this review, snake venom toxins are classified in terms of their abundance and toxicity, and priority actions are being proposed in the search for snake venom metalloproteinase (SVMP), phospholipase A2 (PLA2), three-finger toxin (3FTx), and serine proteinase (SVSP) inhibitors. Natural inhibitors include compounds isolated from plants, animal sera, and mast cells, whereas synthetic inhibitors comprise a wide range of molecules of a variable chemical nature. Some of the most promising inhibitors, especially SVMP and PLA2 inhibitors, have been developed for other diseases and are being repurposed for snakebite envenoming. In addition, the search for drugs aimed at controlling endogenous processes generated in the course of envenoming is being pursued. The present review summarizes some of the most promising developments in this field and discusses issues that need to be considered for the effective translation of this knowledge to improve therapies for tackling snakebite envenoming.
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Affiliation(s)
- José María Gutiérrez
- Facultad de Microbiología, Instituto Clodomiro Picado, Universidad de Costa Rica, San José 11501, Costa Rica; (T.E.); (A.R.)
| | - Laura-Oana Albulescu
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK; (L.-O.A.); (R.H.C.); (N.R.C.)
| | - Rachel H. Clare
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK; (L.-O.A.); (R.H.C.); (N.R.C.)
| | - Nicholas R. Casewell
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK; (L.-O.A.); (R.H.C.); (N.R.C.)
| | - Tarek Mohamed Abd El-Aziz
- Zoology Department, Faculty of Science, Minia University, El-Minia 61519, Egypt;
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229-3900, USA
| | - Teresa Escalante
- Facultad de Microbiología, Instituto Clodomiro Picado, Universidad de Costa Rica, San José 11501, Costa Rica; (T.E.); (A.R.)
| | - Alexandra Rucavado
- Facultad de Microbiología, Instituto Clodomiro Picado, Universidad de Costa Rica, San José 11501, Costa Rica; (T.E.); (A.R.)
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Bekbossynova A, Zharylgap A, Filchakova O. Venom-Derived Neurotoxins Targeting Nicotinic Acetylcholine Receptors. Molecules 2021; 26:molecules26113373. [PMID: 34204855 PMCID: PMC8199771 DOI: 10.3390/molecules26113373] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/05/2021] [Accepted: 05/07/2021] [Indexed: 01/02/2023] Open
Abstract
Acetylcholine was the first neurotransmitter described. The receptors targeted by acetylcholine are found within organisms spanning different phyla and position themselves as very attractive targets for predation, as well as for defense. Venoms of snakes within the Elapidae family, as well as those of marine snails within the Conus genus, are particularly rich in proteins and peptides that target nicotinic acetylcholine receptors (nAChRs). Such compounds are invaluable tools for research seeking to understand the structure and function of the cholinergic system. Proteins and peptides of venomous origin targeting nAChR demonstrate high affinity and good selectivity. This review aims at providing an overview of the toxins targeting nAChRs found within venoms of different animals, as well as their activities and the structural determinants important for receptor binding.
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Dubinnyi MA, Dubovskii PV, Starkov VG, Utkin YN. The omega-loop of cobra cytotoxins tolerates multiple amino acid substitutions. Biochem Biophys Res Commun 2021; 558:141-146. [PMID: 33915327 DOI: 10.1016/j.bbrc.2021.04.069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 04/16/2021] [Indexed: 10/21/2022]
Abstract
Cobra cytotoxins (CTs), the three-fingered proteins, feature high amino acid sequence homology in the beta-strands and variations in the loop regions. We selected a pair of cytotoxins from Naja kaouthia crude venom to clarify the sequence-structure relationships. Using chromatography and mass spectroscopy, we separated and identified the mixture of cytotoxins 2 and 3, differentiated by the only Val 41/Ala 41 substitution. Here, using natural abundance 13C, 15N NMR-spectroscopy we performed chemical shift assignments of the signals of the both toxins in aqueous solution in the major and minor forms. Combining NOE and chemical shift data, the toxins' spatial structure was determined. Finally, we proved that the tip of the "finger"-2, or the loop-2 of cytotoxins adopts the shape of an omega-loop with a tightly-bound water molecule in its cavity. Comparison with other NMR and X-ray structures of cytotoxins possessing different amino acid sequences reveals spatial similarity in this family of proteins, including the loop-2 region, previously considered to be flexible.
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Affiliation(s)
- Maxim A Dubinnyi
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya str., Moscow, 117997, Russia; Moscow Institute of Physics and Technology (State University), 9 Institutskiy per., Dolgoprudny, Moscow Region, 141700, Russia
| | - Peter V Dubovskii
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya str., Moscow, 117997, Russia.
| | - Vladislav G Starkov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya str., Moscow, 117997, Russia
| | - Yuri N Utkin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya str., Moscow, 117997, Russia
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Son L, Kryukova E, Ziganshin R, Andreeva T, Kudryavtsev D, Kasheverov I, Tsetlin V, Utkin Y. Novel Three-Finger Neurotoxins from Naja melanoleuca Cobra Venom Interact with GABA A and Nicotinic Acetylcholine Receptors. Toxins (Basel) 2021; 13:toxins13020164. [PMID: 33672715 PMCID: PMC7924340 DOI: 10.3390/toxins13020164] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 02/16/2021] [Accepted: 02/17/2021] [Indexed: 02/08/2023] Open
Abstract
Cobra venoms contain three-finger toxins (TFT) including α-neurotoxins efficiently binding nicotinic acetylcholine receptors (nAChRs). As shown recently, several TFTs block GABAA receptors (GABAARs) with different efficacy, an important role of the TFTs central loop in binding to these receptors being demonstrated. We supposed that the positive charge (Arg36) in this loop of α-cobratoxin may explain its high affinity to GABAAR and here studied α-neurotoxins from African cobra N. melanoleuca venom for their ability to interact with GABAARs and nAChRs. Three α-neurotoxins, close homologues of the known N. melanoleuca long neurotoxins 1 and 2, were isolated and sequenced. Their analysis on Torpedocalifornica and α7 nAChRs, as well as on acetylcholine binding proteins and on several subtypes of GABAARs, showed that all toxins interacted with the GABAAR much weaker than with the nAChR: one neurotoxin was almost as active as α-cobratoxin, while others manifested lower activity. The earlier hypothesis about the essential role of Arg36 as the determinant of high affinity to GABAAR was not confirmed, but the results obtained suggest that the toxin loop III may contribute to the efficient interaction of some long-chain neurotoxins with GABAAR. One of isolated toxins manifested different affinity to two binding sites on Torpedo nAChR.
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Affiliation(s)
- Lina Son
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia; (L.S.); (E.K.); (R.Z.); (T.A.); (D.K.); (I.K.); (V.T.)
- Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia
| | - Elena Kryukova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia; (L.S.); (E.K.); (R.Z.); (T.A.); (D.K.); (I.K.); (V.T.)
| | - Rustam Ziganshin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia; (L.S.); (E.K.); (R.Z.); (T.A.); (D.K.); (I.K.); (V.T.)
| | - Tatyana Andreeva
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia; (L.S.); (E.K.); (R.Z.); (T.A.); (D.K.); (I.K.); (V.T.)
| | - Denis Kudryavtsev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia; (L.S.); (E.K.); (R.Z.); (T.A.); (D.K.); (I.K.); (V.T.)
| | - Igor Kasheverov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia; (L.S.); (E.K.); (R.Z.); (T.A.); (D.K.); (I.K.); (V.T.)
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, ul. Trubetskaya 8, bld. 2, 119991 Moscow, Russia
| | - Victor Tsetlin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia; (L.S.); (E.K.); (R.Z.); (T.A.); (D.K.); (I.K.); (V.T.)
| | - Yuri Utkin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia; (L.S.); (E.K.); (R.Z.); (T.A.); (D.K.); (I.K.); (V.T.)
- Correspondence: ; Tel.: +7-495-3366522
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Mineev KS, Kryukova EV, Kasheverov IE, Egorova NS, Zhmak MN, Ivanov IA, Senko DA, Feofanov AV, Ignatova AA, Arseniev AS, Utkin YN, Tsetlin VI. Spatial Structure and Activity of Synthetic Fragments of Lynx1 and of Nicotinic Receptor Loop C Models. Biomolecules 2020; 11:biom11010001. [PMID: 33374963 PMCID: PMC7821949 DOI: 10.3390/biom11010001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 12/06/2020] [Accepted: 12/19/2020] [Indexed: 11/16/2022] Open
Abstract
Lynx1, membrane-bound protein co-localized with the nicotinic acetylcholine receptors (nAChRs) and regulates their function, is a three-finger protein (TFP) made of three β-structural loops, similarly to snake venom α-neurotoxin TFPs. Since the central loop II of α-neurotoxins is involved in binding to nAChRs, we have recently synthesized the fragments of Lynx1 central loop, including those with the disulfide between Cys residues introduced at N- and C-termini, some of them inhibiting muscle-type nAChR similarly to the whole-size water-soluble Lynx1 (ws-Lynx1). Literature shows that the main fragment interacting with TFPs is the C-loop of both nAChRs and acetylcholine binding proteins (AChBPs) while some ligand-binding capacity is preserved by analogs of this loop, for example, by high-affinity peptide HAP. Here we analyzed the structural organization of these peptide models of ligands and receptors and its role in binding. Thus, fragments of Lynx1 loop II, loop C from the Lymnaea stagnalis AChBP and HAP were synthesized in linear and Cys-cyclized forms and structurally (CD and NMR) and functionally (radioligand assay on Torpedo nAChR) characterized. Connecting the C- and N-termini by disulfide in the ws-Lynx1 fragment stabilized its conformation which became similar to the loop II within the 1H-NMR structure of ws-Lynx1, the activity being higher than for starting linear fragment but lower than for peptide with free cysteines. Introduced disulfides did not considerably change the structure of HAP and of loop C fragments, the former preserving high affinity for α-bungarotoxin, while, surprisingly, no binding was detected with loop C and its analogs.
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Affiliation(s)
- Konstantin S. Mineev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (E.V.K.); (I.E.K.); (N.S.E.); (M.N.Z.); (I.A.I.); (D.A.S.); (A.V.F.); (A.A.I.); (A.S.A.); (Y.N.U.); (V.I.T.)
- Department of Physico-Chemical Biology and Biotechnology, Moscow Institute of Physics and Technology, 141700 Dolgoprudnyi, Russia
- Correspondence: ; Tel.: +7-(495)-330-74-83
| | - Elena V. Kryukova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (E.V.K.); (I.E.K.); (N.S.E.); (M.N.Z.); (I.A.I.); (D.A.S.); (A.V.F.); (A.A.I.); (A.S.A.); (Y.N.U.); (V.I.T.)
| | - Igor E. Kasheverov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (E.V.K.); (I.E.K.); (N.S.E.); (M.N.Z.); (I.A.I.); (D.A.S.); (A.V.F.); (A.A.I.); (A.S.A.); (Y.N.U.); (V.I.T.)
- Laboratory of Molecular Biology and Biochemistry, Institute of Molecular Medicine, Biomedical Science and Technology Park, Sechenov First Moscow State Medical University, 119991 Moscow, Russia
| | - Natalia S. Egorova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (E.V.K.); (I.E.K.); (N.S.E.); (M.N.Z.); (I.A.I.); (D.A.S.); (A.V.F.); (A.A.I.); (A.S.A.); (Y.N.U.); (V.I.T.)
| | - Maxim N. Zhmak
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (E.V.K.); (I.E.K.); (N.S.E.); (M.N.Z.); (I.A.I.); (D.A.S.); (A.V.F.); (A.A.I.); (A.S.A.); (Y.N.U.); (V.I.T.)
| | - Igor A. Ivanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (E.V.K.); (I.E.K.); (N.S.E.); (M.N.Z.); (I.A.I.); (D.A.S.); (A.V.F.); (A.A.I.); (A.S.A.); (Y.N.U.); (V.I.T.)
| | - Dmitry A. Senko
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (E.V.K.); (I.E.K.); (N.S.E.); (M.N.Z.); (I.A.I.); (D.A.S.); (A.V.F.); (A.A.I.); (A.S.A.); (Y.N.U.); (V.I.T.)
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Alexey V. Feofanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (E.V.K.); (I.E.K.); (N.S.E.); (M.N.Z.); (I.A.I.); (D.A.S.); (A.V.F.); (A.A.I.); (A.S.A.); (Y.N.U.); (V.I.T.)
- Biological Faculty, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Anastasia A. Ignatova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (E.V.K.); (I.E.K.); (N.S.E.); (M.N.Z.); (I.A.I.); (D.A.S.); (A.V.F.); (A.A.I.); (A.S.A.); (Y.N.U.); (V.I.T.)
| | - Alexander S. Arseniev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (E.V.K.); (I.E.K.); (N.S.E.); (M.N.Z.); (I.A.I.); (D.A.S.); (A.V.F.); (A.A.I.); (A.S.A.); (Y.N.U.); (V.I.T.)
| | - Yuri N. Utkin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (E.V.K.); (I.E.K.); (N.S.E.); (M.N.Z.); (I.A.I.); (D.A.S.); (A.V.F.); (A.A.I.); (A.S.A.); (Y.N.U.); (V.I.T.)
| | - Victor I. Tsetlin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (E.V.K.); (I.E.K.); (N.S.E.); (M.N.Z.); (I.A.I.); (D.A.S.); (A.V.F.); (A.A.I.); (A.S.A.); (Y.N.U.); (V.I.T.)
- Institute for Physics and Engineering in Biomedicine, National Research Nuclear University MEPhI, 115409 Moscow, Russia
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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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Tsetlin VI, Kasheverov IE, Utkin YN. Three-finger proteins from snakes and humans acting on nicotinic receptors: Old and new. J Neurochem 2020; 158:1223-1235. [PMID: 32648941 DOI: 10.1111/jnc.15123] [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: 03/22/2020] [Revised: 06/25/2020] [Accepted: 07/06/2020] [Indexed: 12/12/2022]
Abstract
The first toxin to give rise to the three-finger protein (TFP) family was α-bungarotoxin (α-Bgt) from Bungarus multicinctus krait venom. α-Bgt was crucial for research on nicotinic acetylcholine receptors (nAChRs), and in this Review article we focus on present data for snake venom TFPs and those of the Ly6/uPAR family from mammalians (membrane-bound Lynx1 and secreted SLURP-1) interacting with nAChRs. Recently isolated from Bungarus candidus venom, αδ-bungarotoxins differ from α-Bgt: they bind more reversibly and distinguish two binding sites in Torpedo californica nAChR. Naja kaouthia α-cobratoxin, classical blocker of nAChRs, was shown to inhibit certain GABA-A receptor subtypes, whereas α-cobratoxin dimer with 2 intermolecular disulfides has a novel type of 3D structure. Non-conventional toxin WTX has additional 5th disulfide not in the central loop, as α-Bgt, but in the N-terminal loop, like all Ly6/uPAR proteins, and inhibits α7 and Torpedo nAChRs. A water-soluble form of Lynx1, ws-Lynx1, was expressed in E. coli, its 1 H-NMR structure and binding to several nAChRs determined. For SLURP-1, similar information was obtained with its recombinant analogue rSLURP-1. A common feature of ws-Lynx1, rSLURP-1, and WTX is their activity against nAChRs and muscarinic acetylcholine receptors. Synthetic SLURP-1, identical to the natural protein, demonstrated some differences from rSLURP-1 in distinguishing nAChR subtypes. The loop II fragment of the Lynx1 was synthesized having the same µM affinity for the Torpedo nAChR as ws-Lynx1. This review illustrates the productivity of parallel research of nAChR interactions with the two TFP groups.
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Affiliation(s)
- Victor I Tsetlin
- Department of Molecular Neuroimmune Signalling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russian Federation.,PhysBio of MePhi, Moscow, Russian Federation
| | - Igor E Kasheverov
- Department of Molecular Neuroimmune Signalling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russian Federation.,Sechenov First Moscow State Medical University, Institute of Molecular Medicine, Moscow, Russian Federation
| | - Yuri N Utkin
- Department of Molecular Neuroimmune Signalling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russian Federation
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11
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Kini RM. Toxinology provides multidirectional and multidimensional opportunities: A personal perspective. Toxicon X 2020; 6:100039. [PMID: 32550594 PMCID: PMC7285919 DOI: 10.1016/j.toxcx.2020.100039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 04/28/2020] [Accepted: 05/05/2020] [Indexed: 01/16/2023] Open
Abstract
In nature, toxins have evolved as weapons to capture and subdue the prey or to counter predators or competitors. When they are inadvertently injected into humans, they cause symptoms ranging from mild discomfort to debilitation and death. Toxinology is the science of studying venoms and toxins that are produced by a wide variety of organisms. In the past, the structure, function and mechanisms of most abundant and/or most toxic components were characterized to understand and to develop strategies to neutralize their toxicity. With recent technical advances, we are able to evaluate and determine the toxin profiles using transcriptomes of venom glands and proteomes of tiny amounts of venom. Enormous amounts of data from these studies have opened tremendous opportunities in many directions of basic and applied research. The lower costs for profiling venoms will further fuel the expansion of toxin database, which in turn will provide greater exciting and bright opportunities in toxin research.
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Affiliation(s)
- R. Manjunatha Kini
- Protein Science Laboratory, Department of Biological Sciences, Faculty of Science and Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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12
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Rusmili MRA, Othman I, Abidin SAZ, Yusof FA, Ratanabanangkoon K, Chanhome L, Hodgson WC, Chaisakul J. Variations in neurotoxicity and proteome profile of Malayan krait (Bungarus candidus) venoms. PLoS One 2019; 14:e0227122. [PMID: 31887191 PMCID: PMC6936869 DOI: 10.1371/journal.pone.0227122] [Citation(s) in RCA: 7] [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: 05/24/2019] [Accepted: 12/12/2019] [Indexed: 11/18/2022] Open
Abstract
Malayan krait (Bungarus candidus) is a medically important snake species found in Southeast Asia. The neurotoxic effects of envenoming present as flaccid paralysis of skeletal muscles. It is unclear whether geographical variation in venom composition plays a significant role in the degree of clinical neurotoxicity. In this study, the effects of geographical variation on neurotoxicity and venom composition of B. candidus venoms from Indonesia, Malaysia and Thailand were examined. In the chick biventer cervicis nerve-muscle preparation, all venoms abolished indirect twitches and attenuated contractile responses to nicotinic receptor agonists, with venom from Indonesia displaying the most rapid neurotoxicity. A proteomic analysis indicated that three finger toxins (3FTx), phospholipase A2 (PLA2) and Kunitz-type serine protease inhibitors were common toxin groups in the venoms. In addition, venom from Thailand contained L-amino acid oxidase (LAAO), cysteine rich secretory protein (CRISP), thrombin-like enzyme (TLE) and snake venom metalloproteinase (SVMP). Short-chain post-synaptic neurotoxins were not detected in any of the venoms. The largest quantity of long-chain post-synaptic neurotoxins and non-conventional toxins was found in the venom from Thailand. Analysis of PLA2 activity did not show any correlation between the amount of PLA2 and the degree of neurotoxicity of the venoms. Our study shows that variation in venom composition is not limited to the degree of neurotoxicity. This investigation provides additional insights into the geographical differences in venom composition and provides information that could be used to improve the management of Malayan krait envenoming in Southeast Asia.
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Affiliation(s)
- Muhamad Rusdi Ahmad Rusmili
- Kulliyyah of Pharmacy, International Islamic University Malaysia, Kuantan Campus, Bandar Indera Mahkota, Kuantan, Pahang Darul Makmur, Malaysia
| | - Iekhsan Othman
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Sunway Campus, Bandar Sunway, Malaysia
| | - Syafiq Asnawi Zainal Abidin
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Sunway Campus, Bandar Sunway, Malaysia
| | - Fathin Athirah Yusof
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Sunway Campus, Bandar Sunway, Malaysia
| | - Kavi Ratanabanangkoon
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Lawan Chanhome
- Snake Farm, Queen Saovabha Memorial Institute, Thai Red Cross Society, Bangkok, Thailand
| | - Wayne C. Hodgson
- Monash Venom Group, Department of Pharmacology, Biomedical Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Janeyuth Chaisakul
- Department of Pharmacology, Phramongkutklao College of Medicine, Bangkok, Thailand
- * E-mail: ,
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13
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Peigneur S, Devi P, Seldeslachts A, Ravichandran S, Quinton L, Tytgat J. Structure-Function Elucidation of a New α-Conotoxin, MilIA, from Conus milneedwardsi. Mar Drugs 2019; 17:md17090535. [PMID: 31527432 PMCID: PMC6780063 DOI: 10.3390/md17090535] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 09/05/2019] [Accepted: 09/07/2019] [Indexed: 12/16/2022] Open
Abstract
The a-Conotoxins are peptide toxins that are found in the venom of marine cone snails and they are potent antagonists of various subtypes of nicotinic acetylcholine receptors (nAChRs). Because nAChRs have an important role in regulating transmitter release, cell excitability, and neuronal integration, nAChR dysfunctions have been implicated in a variety of severe pathologies. We describe the isolation and characterization of α-conotoxin MilIA, the first conopeptide from the venom of Conus milneedwardsi. The peptide was characterized by electrophysiological screening against several types of cloned nAChRs that were expressed in Xenopus laevis oocytes. MilIA, which is a member of the α3/5 family, is an antagonist of muscle type nAChRs with a high selectivity for muscle versus neuronal subtype nAChRs. Several analogues were designed and investigated for their activity in order to determine the key epitopes of MilIA. Native MilIA and analogues both showed activity at the fetal muscle type nAChR. Two single mutations (Met9 and Asn10) allowed for MilIA to strongly discriminate between the two types of muscle nAChRs. Moreover, one analogue, MilIA [∆1,M2R, M9G, N10K, H11K], displayed a remarkable enhanced potency when compared to native peptide. The key residues that are responsible for switching between muscle and neuronal nAChRs preference were elucidated. Interestingly, the same analogue showed a preference for α9α10 nAChRs among the neuronal types.
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Affiliation(s)
- Steve Peigneur
- Toxicology and Pharmacology, KU Leuven, Campus Gasthuisberg, O & N2, Herestraat 49, P.O. Box 922, 3000 Leuven, Belgium.
| | - Prabha Devi
- Toxicology and Pharmacology, KU Leuven, Campus Gasthuisberg, O & N2, Herestraat 49, P.O. Box 922, 3000 Leuven, Belgium.
- CSIR-National Institute of Oceanography, Dona Paula, Goa 403 004, India.
| | - Andrea Seldeslachts
- Toxicology and Pharmacology, KU Leuven, Campus Gasthuisberg, O & N2, Herestraat 49, P.O. Box 922, 3000 Leuven, Belgium.
| | | | - Loïc Quinton
- Laboratory of Mass Spectrometry, Department of Chemistry, University of Liège, 4000 Liège, Belgium.
| | - Jan Tytgat
- Toxicology and Pharmacology, KU Leuven, Campus Gasthuisberg, O & N2, Herestraat 49, P.O. Box 922, 3000 Leuven, Belgium.
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14
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Albulescu LO, Kazandjian T, Slagboom J, Bruyneel B, Ainsworth S, Alsolaiss J, Wagstaff SC, Whiteley G, Harrison RA, Ulens C, Kool J, Casewell NR. A Decoy-Receptor Approach Using Nicotinic Acetylcholine Receptor Mimics Reveals Their Potential as Novel Therapeutics Against Neurotoxic Snakebite. Front Pharmacol 2019; 10:848. [PMID: 31417406 PMCID: PMC6683245 DOI: 10.3389/fphar.2019.00848] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 07/02/2019] [Indexed: 12/24/2022] Open
Abstract
Snakebite is a neglected tropical disease that causes 138,000 deaths each year. Neurotoxic snake venoms contain small neurotoxins, including three-finger toxins (3FTxs), which can cause rapid paralysis in snakebite victims by blocking postsynaptic transmission via nicotinic acetylcholine receptors (nAChRs). These toxins are typically weakly immunogenic and thus are often not effectively targeted by current polyclonal antivenom therapies. We investigated whether nAChR mimics, also known as acetylcholine binding proteins (AChBPs), could effectively capture 3FTxs and therefore be developed as a novel class of snake-generic therapeutics for combatting neurotoxic envenoming. First, we identified the binding specificities of 3FTx from various medically important elapid snake venoms to nAChR using two recombinant nAChR mimics: the AChBP from Lymnaea stagnalis and a humanized neuronal α7 version (α7-AChBP). We next characterized these AChBP-bound and unbound fractions using SDS-PAGE and mass spectrometry. Interestingly, both mimics effectively captured long-chain 3FTxs from multiple snake species but largely failed to capture the highly related short-chain 3FTxs, suggesting a high level of binding specificity. We next investigated whether nAChR mimics could be used as snakebite therapeutics. We showed that while α7-AChBP alone did not protect against Naja haje (Egyptian cobra) venom lethality in vivo, it significantly prolonged survival times when coadministered with a nonprotective dose of antivenom. Thus, nAChR mimics are capable of neutralizing specific venom toxins and may be useful adjunct therapeutics for improving the safety and affordability of existing snakebite treatments by reducing therapeutic doses. Our findings justify exploring the future development of AChBPs as potential snakebite treatments.
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Affiliation(s)
- Laura-Oana Albulescu
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Taline Kazandjian
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Julien Slagboom
- AIMMS Division of BioMolecular Analysis, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Ben Bruyneel
- AIMMS Division of BioMolecular Analysis, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Stuart Ainsworth
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Jaffer Alsolaiss
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Simon C Wagstaff
- Bioinformatics Unit, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Gareth Whiteley
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Robert A Harrison
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom.,Centre for Drugs and Diagnostics, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Chris Ulens
- Laboratory of Structural Neurobiology, Department of Cellular and Molecular Medicine, Faculty of Medicine, KU Leuven, Leuven, Belgium
| | - Jeroen Kool
- AIMMS Division of BioMolecular Analysis, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Nicholas R Casewell
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom.,Centre for Drugs and Diagnostics, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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15
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Kasheverov IE, Oparin PB, Zhmak MN, Egorova NS, Ivanov IA, Gigolaev AM, Nekrasova OV, Serebryakova MV, Kudryavtsev DS, Prokopev NA, Hoang AN, Tsetlin VI, Vassilevski AA, Utkin YN. Scorpion toxins interact with nicotinic acetylcholine receptors. FEBS Lett 2019; 593:2779-2789. [PMID: 31276191 DOI: 10.1002/1873-3468.13530] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 06/30/2019] [Accepted: 07/01/2019] [Indexed: 12/20/2022]
Abstract
Neurotoxins are among the main components of scorpion and snake venoms. Scorpion neurotoxins affect voltage-gated ion channels, while most snake neurotoxins target ligand-gated ion channels, mainly nicotinic acetylcholine receptors (nAChRs). We report that scorpion venoms inhibit α-bungarotoxin binding to both muscle-type nAChR from Torpedo californica and neuronal human α7 nAChR. Toxins inhibiting nAChRs were identified as OSK-1 (α-KTx family) from Orthochirus scrobiculosus and HelaTx1 (κ-KTx family) from Heterometrus laoticus, both being blockers of voltage-gated potassium channels. With an IC50 of 1.6 μm, OSK1 inhibits acetylcholine-induced current through mouse muscle-type nAChR heterologously expressed in Xenopus oocytes. Other well-characterized scorpion toxins from these families also bind to Torpedo nAChR with micromolar affinities. Our results indicate that scorpion neurotoxins present target promiscuity.
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Affiliation(s)
- Igor E Kasheverov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.,Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Peter B Oparin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Maxim N Zhmak
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Natalya S Egorova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Igor A Ivanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Andrei M Gigolaev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Oksana V Nekrasova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Marina V Serebryakova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Russia
| | - Denis S Kudryavtsev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Nikita A Prokopev
- Department of Bioorganic Chemistry, Faculty of Biology, Lomonosov Moscow State University, Russia
| | - Anh N Hoang
- Institute of Applied Materials Science, Vietnam Academy of Science and Technology, Ho Chi Minh City, Vietnam
| | - Victor I Tsetlin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Alexander A Vassilevski
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.,Moscow Institute of Physics and Technology (State University), Dolgoprudny, Moscow Oblast, Russia
| | - Yuri N Utkin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
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16
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Toxins for decoding interface selectivity in nicotinic acetylcholine receptors. Biochem J 2019; 476:1515-1520. [PMID: 31138769 DOI: 10.1042/bcj20190255] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 04/29/2019] [Accepted: 05/03/2019] [Indexed: 01/25/2023]
Abstract
Nicotinic acetylcholine receptors (nAChRs) are pentameric ligand-gated ion channels that play crucial roles in neurotransmission and regulate complex processes in brain functions, including anxiety, learning and memory, food intake, drug addiction, cognition and nociception. To perform these and other functions, a diverse array of nAChR subtypes are generated by homomeric or heteromeric assembly of 17 homologous nAChR subunits. Agonists, acetylcholine and nicotine, bind to the interface formed between two α subunits and between α and non-α subunits to activate the nAChR and allow cation influx. The diversity of subunit interfaces determines the channel properties, the responses to different agonists/antagonists, desensitization and downstream signaling and thus, define specialized properties and functions. Over the last several decades, snake venom neurotoxins have contributed to the purification, localization and characterization of molecular details of various nAChRs. Utkin et al. have described the purification and characterization of αδ-bungarotoxins, a novel class of neurotoxins in a recent paper published in the Biochemical Journal [Biochem. J. (2019) 476, 1285-1302]. These toxins from Bungarus candidus venom preferably bind to α-δ site with two orders of magnitude higher affinity compared with α-γ or α-ε sites. The subtle changes in the structure of αδ-bungarotoxins led to variation in interface selectivity. Such new classes of antagonists will offer us great opportunity to delineate the pharmacophores and design new highly selective antagonists. Thus, their findings provide new impetus to re-evaluate molecular details of pharmacological properties of α-neurotoxins with careful consideration towards subtype-, interface- and species-selectivity.
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