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Cheng Y, Hyodo T, Yamaguchi K, Ohwada T, Otani Y. Complete amide cis- trans switching synchronized with disulfide bond formation and cleavage in a proline-mimicking system. Chem Commun (Camb) 2024; 60:6158-6161. [PMID: 38804552 DOI: 10.1039/d4cc01096e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
A typical naturally occurring disulfide structure in proteins is an 8-membered disulfide ring formed between two adjacent cysteine (Cys-Cys) residues. Based on this structure, we designed 7- to 9-membered disulfide ring molecules, embedded in the 7-azabicyclo[2.2.1]heptane skeleton, that switch their conformation from exclusively trans-amide to exclusively cis-amide upon redox transformation from dithiol to disulfide, and vice versa. Constrained shape of disulfide rings is rare in nature, and the present molecular structure is expected to be a useful fundamental component for the construction of new conformation-switching systems.
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Affiliation(s)
- Yuhe Cheng
- Graduate School of Pharmaceutical Sciences, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
| | - Tadashi Hyodo
- School of Pharmaceutical Sciences at Kagawa Campus, Tokushima Bunri University, 1314-1 Shido, Sanuki, Kagawa 769-2193, Japan
| | - Kentaro Yamaguchi
- School of Pharmaceutical Sciences at Kagawa Campus, Tokushima Bunri University, 1314-1 Shido, Sanuki, Kagawa 769-2193, Japan
| | - Tomohiko Ohwada
- Graduate School of Pharmaceutical Sciences, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
| | - Yuko Otani
- Graduate School of Pharmaceutical Sciences, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
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2
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Reddy KA, Sahoo DK, Moi S, Gowd KH. Conformational change due to replacement of disulfide with selenosulfide and diselenide in dipeptide vicinal cysteine loop. Comput Biol Chem 2022; 97:107635. [DOI: 10.1016/j.compbiolchem.2022.107635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 12/21/2021] [Accepted: 01/17/2022] [Indexed: 11/16/2022]
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3
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Rivera-de-Torre E, Rimbault C, Jenkins TP, Sørensen CV, Damsbo A, Saez NJ, Duhoo Y, Hackney CM, Ellgaard L, Laustsen AH. Strategies for Heterologous Expression, Synthesis, and Purification of Animal Venom Toxins. Front Bioeng Biotechnol 2022; 9:811905. [PMID: 35127675 PMCID: PMC8811309 DOI: 10.3389/fbioe.2021.811905] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 12/24/2021] [Indexed: 11/13/2022] Open
Abstract
Animal venoms are complex mixtures containing peptides and proteins known as toxins, which are responsible for the deleterious effect of envenomations. Across the animal Kingdom, toxin diversity is enormous, and the ability to understand the biochemical mechanisms governing toxicity is not only relevant for the development of better envenomation therapies, but also for exploiting toxin bioactivities for therapeutic or biotechnological purposes. Most of toxinology research has relied on obtaining the toxins from crude venoms; however, some toxins are difficult to obtain because the venomous animal is endangered, does not thrive in captivity, produces only a small amount of venom, is difficult to milk, or only produces low amounts of the toxin of interest. Heterologous expression of toxins enables the production of sufficient amounts to unlock the biotechnological potential of these bioactive proteins. Moreover, heterologous expression ensures homogeneity, avoids cross-contamination with other venom components, and circumvents the use of crude venom. Heterologous expression is also not only restricted to natural toxins, but allows for the design of toxins with special properties or can take advantage of the increasing amount of transcriptomics and genomics data, enabling the expression of dormant toxin genes. The main challenge when producing toxins is obtaining properly folded proteins with a correct disulfide pattern that ensures the activity of the toxin of interest. This review presents the strategies that can be used to express toxins in bacteria, yeast, insect cells, or mammalian cells, as well as synthetic approaches that do not involve cells, such as cell-free biosynthesis and peptide synthesis. This is accompanied by an overview of the main advantages and drawbacks of these different systems for producing toxins, as well as a discussion of the biosafety considerations that need to be made when working with highly bioactive proteins.
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Affiliation(s)
- Esperanza Rivera-de-Torre
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
- *Correspondence: Esperanza Rivera-de-Torre, ; Andreas H. Laustsen,
| | - Charlotte Rimbault
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Timothy P. Jenkins
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Christoffer V. Sørensen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Anna Damsbo
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Natalie J. Saez
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, Australia
| | - Yoan Duhoo
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, Australia
| | - Celeste Menuet Hackney
- Department of Biology, Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, Copenhagen, Denmark
| | - Lars Ellgaard
- Department of Biology, Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, Copenhagen, Denmark
| | - Andreas H. Laustsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
- *Correspondence: Esperanza Rivera-de-Torre, ; Andreas H. Laustsen,
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4
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Prabakaran P, Chowdhury PS. Landscape of Non-canonical Cysteines in Human V H Repertoire Revealed by Immunogenetic Analysis. Cell Rep 2021; 31:107831. [PMID: 32610132 PMCID: PMC7326410 DOI: 10.1016/j.celrep.2020.107831] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 04/02/2020] [Accepted: 06/08/2020] [Indexed: 12/21/2022] Open
Abstract
Human antibody repertoire data captured through next-generation sequencing (NGS) has enabled deeper insights into B cell immunogenetics and paratope diversity. By analyzing large public NGS datasets, we map the landscape of non-canonical cysteines in human variable heavy-chain domains (VHs) at the repertoire level. We identify remarkable usage of non-canonical cysteines within the heavy-chain complementarity-determining region 3 (CDR-H3) and other CDRs and framework regions. Furthermore, our study reveals the diversity and location of non-canonical cysteines and their associated motifs in human VHs, which are reminiscent of and more complex than those found in other non-human species such as chicken, camel, llama, shark, and cow. These results explain how non-canonical cysteines strategically occur in the human antibodyome to expand its paratope space. This study will guide the design of human antibodies harboring disulfide-stabilized long CDR-H3s to access difficult-to-target epitopes and influence a paradigm shift in developability involving non-canonical cysteines. NGS-based non-canonical cysteine landscape in human VHs 1 to 8 non-canonical cysteines and up to 30% in long CDR-H3s An array of potential disulfide motifs adds paratope diversity Non-canonical cysteines in human VHs are reminiscent of lower animals
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Touchard A, Mendel HC, Boulogne I, Herzig V, Braga Emidio N, King GF, Triquigneaux M, Jaquillard L, Beroud R, De Waard M, Delalande O, Dejean A, Muttenthaler M, Duplais C. Heterodimeric Insecticidal Peptide Provides New Insights into the Molecular and Functional Diversity of Ant Venoms. ACS Pharmacol Transl Sci 2020; 3:1211-1224. [PMID: 33344898 DOI: 10.1021/acsptsci.0c00119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Indexed: 12/14/2022]
Abstract
Ants use venom for predation, defense, and communication; however, the molecular diversity, function, and potential applications of ant venom remains understudied compared to other venomous lineages such as arachnids, snakes and cone snails. In this work, we used a multidisciplinary approach that encompassed field work, proteomics, sequencing, chemical synthesis, structural analysis, molecular modeling, stability studies, and in vitro and in vivo bioassays to investigate the molecular diversity of the venom of the Amazonian Pseudomyrmex penetrator ants. We isolated a potent insecticidal heterodimeric peptide Δ-pseudomyrmecitoxin-Pp1a (Δ-PSDTX-Pp1a) composed of a 27-residue long A-chain and a 33-residue long B-chain cross-linked by two disulfide bonds in an antiparallel orientation. We chemically synthesized Δ-PSDTX-Pp1a, its corresponding parallel AA and BB homodimers, and its monomeric chains and demonstrated that Δ-PSDTX-Pp1a had the most potent insecticidal effects in blowfly assays (LD50 = 3 nmol/g). Molecular modeling and circular dichroism studies revealed strong α-helical features, indicating its cytotoxic effects could derive from cell membrane pore formation or disruption. The native heterodimer was substantially more stable against proteolytic degradation (t 1/2 = 13 h) than its homodimers or monomers (t 1/2 < 20 min), indicating an evolutionary advantage of the more complex structure. The proteomic analysis of Pseudomyrmex penetrator venom and in-depth characterization of Δ-PSDTX-Pp1a provide novel insights in the structural complexity of ant venom and further exemplifies how nature exploits disulfide-bond formation and dimerization to gain an evolutionary advantage via improved stability, a concept that is highly relevant for the design and development of peptide therapeutics, molecular probes, and bioinsecticides.
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Affiliation(s)
- Axel Touchard
- CNRS, UMR Ecofog, AgroParisTech, Cirad, INRAE, Université des Antilles, Université de Guyane, Kourou 97310, France
| | - Helen C Mendel
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Isabelle Boulogne
- Université de ROUEN, UFR des Sciences et Techniques, Laboratoire Glycobiologie et Matrice Extracellulaire Végétale, UPRES-EA 4358, Fédération de Recherche Normandie Végétal FED 4277, Mont-Saint-Aignan 76821, France
| | - Volker Herzig
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia.,GeneCology Research Centre, School of Science, Technology and Engineering, University of the Sunshine Coast, Sippy Downs, Queensland 4556, Australia
| | - Nayara Braga Emidio
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | | | - Lucie Jaquillard
- Smartox Biotechnology, 6 rue des Platanes, Saint Egrève 38120, France
| | - Rémy Beroud
- Smartox Biotechnology, 6 rue des Platanes, Saint Egrève 38120, France
| | - Michel De Waard
- Smartox Biotechnology, 6 rue des Platanes, Saint Egrève 38120, France.,Université de Nantes, CNRS, INSERM, L'institut du thorax, Nantes 44000, France.,LabEx, Ion Channels, Science & Therapeutics, Valbonne 06560, France
| | - Olivier Delalande
- Institute of Genetics and Development of Rennes (IGDR), CNRS UMR 6290, Université de Rennes Faculté de Pharmacie, 2 avenue du Professeur Léon Bernard, Rennes 35043, France
| | - Alain Dejean
- CNRS, UMR Ecofog, AgroParisTech, Cirad, INRAE, Université des Antilles, Université de Guyane, Kourou 97310, France.,Ecolab, Université de Toulouse, CNRS, INPT, UPS, Toulouse 31058, France
| | - Markus Muttenthaler
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia.,Institute of Biological Chemistry, Faculty of Chemistry, University of Vienna, Vienna 1090, Austria
| | - Christophe Duplais
- CNRS, UMR Ecofog, AgroParisTech, Cirad, INRAE, Université des Antilles, Université de Guyane, Kourou 97310, France
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6
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McCarthy S, Robinson J, Thalassinos K, Tabor AB. A Chemical Biology Approach to Probing the Folding Pathways of the Inhibitory Cystine Knot (ICK) Peptide ProTx-II. Front Chem 2020; 8:228. [PMID: 32309273 PMCID: PMC7145985 DOI: 10.3389/fchem.2020.00228] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 03/10/2020] [Indexed: 11/24/2022] Open
Abstract
Peptide toxins that adopt the inhibitory cystine knot (ICK) scaffold have very stable three-dimensional structures as a result of the conformational constraints imposed by the configuration of the three disulfide bonds that are the hallmark of this fold. Understanding the oxidative folding pathways of these complex peptides, many of which are important therapeutic leads, is important in order to devise reliable synthetic routes to correctly folded, biologically active peptides. Previous research on the ICK peptide ProTx-II has shown that in the absence of an equilibrating redox buffer, misfolded intermediates form that prevent the formation of the native disulfide bond configuration. In this paper, we used tandem mass spectrometry to examine these misfolded peptides, and identified two non-native singly bridged peptides, one with a Cys(III)-Cys(IV) linkage and one with a Cys(V)-Cys(VI) linkage. Based on these results, we propose that the C-terminus of ProTx-II has an important role in initiating the folding of this peptide. To test this hypothesis, we have also studied the folding pathways of analogs of ProTx-II containing the disulfide-bond directing group penicillamine (Pen) under the same conditions. We find that placing Pen residues at the C-terminus of the ProTx-II analogs directs the folding pathway away from the singly bridged misfolded intermediates that represent a kinetic trap for the native sequence, and allows a fully oxidized final product to be formed with three disulfide bridges. However, multiple two-disulfide peptides were also produced, indicating that further study is required to fully control the folding pathways of this modified scaffold.
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Affiliation(s)
| | | | - Konstantinos Thalassinos
- Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck College, University of London, London, United Kingdom.,Division of Biosciences, Institute of Structural and Molecular Biology, University College London, London, United Kingdom
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Evaluation of Chemical Strategies for Improving the Stability and Oral Toxicity of Insecticidal Peptides. Biomedicines 2018; 6:biomedicines6030090. [PMID: 30154370 PMCID: PMC6164231 DOI: 10.3390/biomedicines6030090] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 08/22/2018] [Accepted: 08/23/2018] [Indexed: 12/18/2022] Open
Abstract
Spider venoms are a rich source of insecticidal peptide toxins. Their development as bioinsecticides has, however, been hampered due to concerns about potential lack of stability and oral bioactivity. We therefore systematically evaluated several synthetic strategies to increase the stability and oral potency of the potent insecticidal spider-venom peptide ω-HXTX-Hv1a (Hv1a). Selective chemical replacement of disulfide bridges with diselenide bonds and N- to C-terminal cyclization were anticipated to improve Hv1a resistance to proteolytic digestion, and thereby its activity when delivered orally. We found that native Hv1a is orally active in blowflies, but 91-fold less potent than when administered by injection. Introduction of a single diselenide bond had no effect on the susceptibility to scrambling or the oral activity of Hv1a. N- to C-terminal cyclization of the peptide backbone did not significantly improve the potency of Hv1a when injected into blowflies and it led to a significant decrease in oral activity. We show that this is likely due to a dramatically reduced rate of translocation of cyclic Hv1a across the insect midgut, highlighting the importance of testing bioavailability in addition to toxin stability.
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8
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Guo S, Herzig V, King GF. Dipteran toxicity assays for determining the oral insecticidal activity of venoms and toxins. Toxicon 2018; 150:297-303. [DOI: 10.1016/j.toxicon.2018.06.077] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 06/07/2018] [Accepted: 06/15/2018] [Indexed: 12/19/2022]
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9
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Structural space of intramolecular peptide disulfides: Analysis of peptide toxins retrieved from venomous peptide databases. Comput Biol Chem 2017; 68:194-203. [DOI: 10.1016/j.compbiolchem.2017.03.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2016] [Revised: 02/21/2017] [Accepted: 03/06/2017] [Indexed: 01/22/2023]
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10
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Ikonomopoulou MP, Smith JJ, Herzig V, Pineda SS, Dziemborowicz S, Er SY, Durek T, Gilchrist J, Alewood PF, Nicholson GM, Bosmans F, King GF. Isolation of two insecticidal toxins from venom of the Australian theraphosid spider Coremiocnemis tropix. Toxicon 2016; 123:62-70. [PMID: 27793656 DOI: 10.1016/j.toxicon.2016.10.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 10/21/2016] [Accepted: 10/25/2016] [Indexed: 01/13/2023]
Abstract
Sheep flystrike is caused by parasitic flies laying eggs on soiled wool or open wounds, after which the hatched maggots feed on the sheep flesh and often cause large lesions. It is a significant economic problem for the livestock industry as infestations are difficult to control due to ongoing cycles of larval development into flies followed by further egg laying. We therefore screened venom fractions from the Australian theraphosid spider Coremiocnemis tropix to identify toxins active against the sheep blowfly Lucilia cuprina, which is the primary cause of flystrike in Australia. This screen led to isolation of two insecticidal peptides, Ct1a and Ct1b, that are lethal to blowflies within 24 h of injection. The primary structure of these peptides was determined using a combination of Edman degradation and sequencing of a C. tropix venom-gland transcriptome. Ct1a and Ct1b contain 39 and 38 amino acid residues, respectively, including six cysteine residues that form three disulfide bonds. Recombinant production in bacteria (Escherichia coli) resulted in low yields of Ct1a whereas solid-phase peptide synthesis using native chemical ligation produced sufficient quantities of Ct1a for functional analyses. Synthetic Ct1a had no effect on voltage-gated sodium channels from the American cockroach Periplanata americana or the German cockroach Blattella germanica, but it was lethal to sheep blowflies with an LD50 of 1687 pmol/g.
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Affiliation(s)
- Maria P Ikonomopoulou
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Jennifer J Smith
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Volker Herzig
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Sandy S Pineda
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
| | | | - Sing-Yan Er
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Thomas Durek
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - John Gilchrist
- Department of Physiology & Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA
| | - Paul F Alewood
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Graham M Nicholson
- School of Life Sciences, University of Technology Sydney, NSW 2007, Australia
| | - Frank Bosmans
- Department of Physiology & Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia.
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11
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Herzig V, Ikonomopoulou M, Smith JJ, Dziemborowicz S, Gilchrist J, Kuhn-Nentwig L, Rezende FO, Moreira LA, Nicholson GM, Bosmans F, King GF. Molecular basis of the remarkable species selectivity of an insecticidal sodium channel toxin from the African spider Augacephalus ezendami. Sci Rep 2016; 6:29538. [PMID: 27383378 PMCID: PMC4935840 DOI: 10.1038/srep29538] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 06/20/2016] [Indexed: 12/30/2022] Open
Abstract
The inexorable decline in the armament of registered chemical insecticides has stimulated research into environmentally-friendly alternatives. Insecticidal spider-venom peptides are promising candidates for bioinsecticide development but it is challenging to find peptides that are specific for targeted pests. In the present study, we isolated an insecticidal peptide (Ae1a) from venom of the African spider Augacephalus ezendami (family Theraphosidae). Injection of Ae1a into sheep blowflies (Lucilia cuprina) induced rapid but reversible paralysis. In striking contrast, Ae1a was lethal to closely related fruit flies (Drosophila melanogaster) but induced no adverse effects in the recalcitrant lepidopteran pest Helicoverpa armigera. Electrophysiological experiments revealed that Ae1a potently inhibits the voltage-gated sodium channel BgNaV1 from the German cockroach Blattella germanica by shifting the threshold for channel activation to more depolarized potentials. In contrast, Ae1a failed to significantly affect sodium currents in dorsal unpaired median neurons from the American cockroach Periplaneta americana. We show that Ae1a interacts with the domain II voltage sensor and that sensitivity to the toxin is conferred by natural sequence variations in the S1–S2 loop of domain II. The phyletic specificity of Ae1a provides crucial information for development of sodium channel insecticides that target key insect pests without harming beneficial species.
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Affiliation(s)
- Volker Herzig
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Maria Ikonomopoulou
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Jennifer J Smith
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Sławomir Dziemborowicz
- School of Medical &Molecular Biosciences, University of Technology, Sydney, NSW 2007, Australia
| | - John Gilchrist
- Department of Physiology &Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA
| | - Lucia Kuhn-Nentwig
- Institute of Ecology &Evolution, University of Bern, CH 3012 Bern, Switzerland
| | | | | | - Graham M Nicholson
- School of Medical &Molecular Biosciences, University of Technology, Sydney, NSW 2007, Australia
| | - Frank Bosmans
- Department of Physiology &Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
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12
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Burnley J, Jackson WR, Robinson AJ. One-Pot Selective Homodimerization/Hydrogenation Strategy for Sequential Dicarba Bridge Formation. J Org Chem 2015; 80:9057-63. [DOI: 10.1021/acs.joc.5b01312] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- James Burnley
- School of Chemistry, Monash University, Clayton, 3800 Victoria, Australia
| | - W. Roy Jackson
- School of Chemistry, Monash University, Clayton, 3800 Victoria, Australia
| | - Andrea J. Robinson
- School of Chemistry, Monash University, Clayton, 3800 Victoria, Australia
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13
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Ruggles EL, Deker PB, Hondal RJ. Conformational analysis of oxidized peptide fragments of the C-terminal redox center in thioredoxin reductases by NMR spectroscopy. J Pept Sci 2014; 20:349-60. [PMID: 24599608 DOI: 10.1002/psc.2620] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 01/25/2014] [Accepted: 01/27/2014] [Indexed: 11/06/2022]
Abstract
Vicinal disulfide rings (VDRs) occur when a disulfide bond forms between adjacent cysteine residues in a protein and results in a rare eight-membered ring structure. This eight-membered ring has been found to exist in four major conformations in solution, divided between cis and trans conformers. Some selenoenzymes use a special type of VDR in which selenium replaces sulfur, generating a vicinal selenosulfide ring (VSeSR). Here, we provide evidence that this substitution reduces ring strain, resulting in a strong preference for the trans conformation relative to cis in a VSeSR (cis:trans - 9:91). This was determined by using the 'γ-gauche effect', which makes use of both (1) H-NMR and two-dimensional (2D) NMR techniques for determining the amide bond conformeric ratio. The presence of selenium in a VSeSR also lowers the dihedral strain energy (DSE) of the selenosulfide bond relative to the disulfide bond of VDRs. While cis amide geometry decreases strain on the amide bond, it increases strain on the scissile disulfide bond of the VDR found in thioredoxin reductase from Drosophila melanogaster (DmTR). We hypothesize that the cis conformation of the VDR is the catalytically competent conformer for thiol/disulfide exchange. This hypothesis was investigated by computing the DSE of VDR and VSeSR conformers, the structure of which was determined by 2D NMR spectroscopy and energy minimization. The computed values of the VDR from DmTR are 16.5 kJ/mol DSE and 14.3 kJ/mol for the C+ and T- conformers, respectively, supporting the hypothesis that the enzyme uses the C+ conformer for thiol/disulfide exchange.
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Affiliation(s)
- Erik L Ruggles
- Department of Biochemistry, University of Vermont, 89 Beaumont Ave, Given Laboratory, Room B413, Burlington, VT, 05405, USA
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14
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Pineda SS, Sollod BL, Wilson D, Darling A, Sunagar K, Undheim EAB, Kely L, Antunes A, Fry BG, King GF. Diversification of a single ancestral gene into a successful toxin superfamily in highly venomous Australian funnel-web spiders. BMC Genomics 2014; 15:177. [PMID: 24593665 PMCID: PMC4029134 DOI: 10.1186/1471-2164-15-177] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 02/26/2014] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND Spiders have evolved pharmacologically complex venoms that serve to rapidly subdue prey and deter predators. The major toxic factors in most spider venoms are small, disulfide-rich peptides. While there is abundant evidence that snake venoms evolved by recruitment of genes encoding normal body proteins followed by extensive gene duplication accompanied by explosive structural and functional diversification, the evolutionary trajectory of spider-venom peptides is less clear. RESULTS Here we present evidence of a spider-toxin superfamily encoding a high degree of sequence and functional diversity that has evolved via accelerated duplication and diversification of a single ancestral gene. The peptides within this toxin superfamily are translated as prepropeptides that are posttranslationally processed to yield the mature toxin. The N-terminal signal sequence, as well as the protease recognition site at the junction of the propeptide and mature toxin are conserved, whereas the remainder of the propeptide and mature toxin sequences are variable. All toxin transcripts within this superfamily exhibit a striking cysteine codon bias. We show that different pharmacological classes of toxins within this peptide superfamily evolved under different evolutionary selection pressures. CONCLUSIONS Overall, this study reinforces the hypothesis that spiders use a combinatorial peptide library strategy to evolve a complex cocktail of peptide toxins that target neuronal receptors and ion channels in prey and predators. We show that the ω-hexatoxins that target insect voltage-gated calcium channels evolved under the influence of positive Darwinian selection in an episodic fashion, whereas the κ-hexatoxins that target insect calcium-activated potassium channels appear to be under negative selection. A majority of the diversifying sites in the ω-hexatoxins are concentrated on the molecular surface of the toxins, thereby facilitating neofunctionalisation leading to new toxin pharmacology.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Bryan G Fry
- Institute for Molecular Bioscience, The University of Queensland, 306 Carmody Road, St Lucia, QLD 4072, Australia.
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