1
|
Kessler P, Marchot P, Silva M, Servent D. The three-finger toxin fold: a multifunctional structural scaffold able to modulate cholinergic functions. J Neurochem 2017; 142 Suppl 2:7-18. [PMID: 28326549 DOI: 10.1111/jnc.13975] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 01/12/2017] [Accepted: 01/30/2017] [Indexed: 12/26/2022]
Abstract
Three-finger fold toxins are miniproteins frequently found in Elapidae snake venoms. This fold is characterized by three distinct loops rich in β-strands and emerging from a dense, globular core reticulated by four highly conserved disulfide bridges. The number and diversity of receptors, channels, and enzymes identified as targets of three-finger fold toxins is increasing continuously. Such manifold diversity highlights the specific adaptability of this fold for generating pleiotropic functions. Although this toxin superfamily disturbs many biological functions by interacting with a large diversity of molecular targets, the most significant target is the cholinergic system. By blocking the activity of the nicotinic and muscarinic acetylcholine receptors or by inhibiting the enzyme acetylcholinesterase, three-finger fold toxins interfere most drastically with neuromuscular junction functioning. Several of these toxins have become powerful pharmacological tools for studying the function and structure of their molecular targets. Most importantly, since dysfunction of these receptors/enzyme is involved in many diseases, exploiting the three-finger scaffold to create novel, highly specific therapeutic agents may represent a major future endeavor. This is an article for the special issue XVth International Symposium on Cholinergic Mechanisms.
Collapse
Affiliation(s)
- Pascal Kessler
- Service d'Ingénierie Moléculaire des Protéines (SIMOPRO), IBITECS, CEA, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Pascale Marchot
- Aix-Marseille Université/Centre National de la Recherche Scientifique, Architecture et Fonction des Macromolécules Biologiques laboratory, Faculté des Sciences Campus Luminy, Marseille, France
| | - Marcela Silva
- Service d'Ingénierie Moléculaire des Protéines (SIMOPRO), IBITECS, CEA, Université Paris-Saclay, Gif-sur-Yvette, France.,Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Denis Servent
- Service d'Ingénierie Moléculaire des Protéines (SIMOPRO), IBITECS, CEA, Université Paris-Saclay, Gif-sur-Yvette, France
| |
Collapse
|
2
|
Fruchart-Gaillard C, Mourier G, Blanchet G, Vera L, Gilles N, Ménez R, Marcon E, Stura EA, Servent D. Engineering of three-finger fold toxins creates ligands with original pharmacological profiles for muscarinic and adrenergic receptors. PLoS One 2012; 7:e39166. [PMID: 22720062 PMCID: PMC3375269 DOI: 10.1371/journal.pone.0039166] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 05/16/2012] [Indexed: 01/26/2023] Open
Abstract
Protein engineering approaches are often a combination of rational design and directed evolution using display technologies. Here, we test “loop grafting,” a rational design method, on three-finger fold proteins. These small reticulated proteins have exceptional affinity and specificity for their diverse molecular targets, display protease-resistance, and are highly stable and poorly immunogenic. The wealth of structural knowledge makes them good candidates for protein engineering of new functionality. Our goal is to enhance the efficacy of these mini-proteins by modifying their pharmacological properties in order to extend their use in imaging, diagnostics and therapeutic applications. Using the interaction of three-finger fold toxins with muscarinic and adrenergic receptors as a model, chimeric toxins have been engineered by substituting loops on toxin MT7 by those from toxin MT1. The pharmacological impact of these grafts was examined using binding experiments on muscarinic receptors M1 and M4 and on the α1A-adrenoceptor. Some of the designed chimeric proteins have impressive gain of function on certain receptor subtypes achieving an original selectivity profile with high affinity for muscarinic receptor M1 and α1A-adrenoceptor. Structure-function analysis supported by crystallographic data for MT1 and two chimeras permits a molecular based interpretation of these gains and details the merits of this protein engineering technique. The results obtained shed light on how loop permutation can be used to design new three-finger proteins with original pharmacological profiles.
Collapse
Affiliation(s)
- Carole Fruchart-Gaillard
- CEA, iBiTecS, Service d’Ingénierie Moléculaire des Protéines, Laboratoire de Toxinologie Moléculaire et Biotechnologies, Gif-sur-Yvette, France
| | - Gilles Mourier
- CEA, iBiTecS, Service d’Ingénierie Moléculaire des Protéines, Laboratoire de Toxinologie Moléculaire et Biotechnologies, Gif-sur-Yvette, France
| | - Guillaume Blanchet
- CEA, iBiTecS, Service d’Ingénierie Moléculaire des Protéines, Laboratoire de Toxinologie Moléculaire et Biotechnologies, Gif-sur-Yvette, France
- Université Pierre et Marie Curie, Paris, France
| | - Laura Vera
- CEA, iBiTecS, Service d’Ingénierie Moléculaire des Protéines, Laboratoire de Toxinologie Moléculaire et Biotechnologies, Gif-sur-Yvette, France
| | - Nicolas Gilles
- CEA, iBiTecS, Service d’Ingénierie Moléculaire des Protéines, Laboratoire de Toxinologie Moléculaire et Biotechnologies, Gif-sur-Yvette, France
| | - Renée Ménez
- CEA, iBiTecS, Service d’Ingénierie Moléculaire des Protéines, Laboratoire de Toxinologie Moléculaire et Biotechnologies, Gif-sur-Yvette, France
| | - Elodie Marcon
- CEA, iBiTecS, Service d’Ingénierie Moléculaire des Protéines, Laboratoire de Toxinologie Moléculaire et Biotechnologies, Gif-sur-Yvette, France
| | - Enrico A. Stura
- CEA, iBiTecS, Service d’Ingénierie Moléculaire des Protéines, Laboratoire de Toxinologie Moléculaire et Biotechnologies, Gif-sur-Yvette, France
| | - Denis Servent
- CEA, iBiTecS, Service d’Ingénierie Moléculaire des Protéines, Laboratoire de Toxinologie Moléculaire et Biotechnologies, Gif-sur-Yvette, France
- * E-mail:
| |
Collapse
|
3
|
Kini RM, Doley R. Structure, function and evolution of three-finger toxins: mini proteins with multiple targets. Toxicon 2010; 56:855-67. [PMID: 20670641 DOI: 10.1016/j.toxicon.2010.07.010] [Citation(s) in RCA: 252] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2010] [Accepted: 07/19/2010] [Indexed: 12/15/2022]
Abstract
Snake venoms are complex mixtures of pharmacologically active peptides and proteins. These protein toxins belong to a small number of superfamilies of proteins. Three-finger toxins belong to a superfamily of non-enzymatic proteins found in all families of snakes. They have a common structure of three beta-stranded loops extending from a central core containing all four conserved disulphide bonds. Despite the common scaffold, they bind to different receptors/acceptors and exhibit a wide variety of biological effects. Thus, the structure-function relationships of this group of toxins are complicated and challenging. Studies have shown that the functional sites in these 'sibling' toxins are located on various segments of the molecular surface. Targeting to a wide variety of receptors and ion channels and hence distinct functions in this group of mini proteins is achieved through a combination of accelerated rate of exchange of segments as well as point mutations in exons. In this review, we describe the structural and functional diversity, structure-function relationships and evolution of this group of snake venom toxins.
Collapse
Affiliation(s)
- R Manjunatha Kini
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore 117543, Singapore.
| | | |
Collapse
|
4
|
Wang J, Gu J, Leszczynski J. A model study of interactions between TcAChE peripheral site segment Tyr70Val71 and loop 1 of Fasciculin 2. J Biomol Struct Dyn 2006; 24:139-48. [PMID: 16928137 DOI: 10.1080/07391102.2006.10507107] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The continuous chain of residues (Thr7 to Ala12) of Loop1 of Fas2 (F1) and its interaction with the peripheral binding sites (Tyr70-Val71) of AChE (P1) has been studied. Our results suggest that the flexibility of Loop1 might be caused by either the partially protonated guanidine group of Arg11 under experimental conditions or by the interaction with the negatively charged center of substrates. The binding energy of F1-P1 is predicted to be -16.6 kcal/mol at the B3LYP/6-311G(d,p) level, which is assumed to originate from one isolated O7...HN10 H-bond, one possible O10...HC71 unconventional O...HC type H-bonding, and the improved pi-bonding cooperativity around the peptide group of the AChE segment Tyr70-Val71. The classical Kitaura-Morokuma energy decomposition analysis, the NPA charge analysis, and the AIM analysis consistently reveal that the peptide group in segment P1 is more polarizable, which might play the key role in the interactions between F1 and P1. The PCM solvent effect corrected results reveal decrease of the interaction energy of the considered model. The importance of Thr8 of Fas2 in the P-site binding of AChE is also concluded. Site-directed mutations on either the Fas2 residue of Thr8 or the AChE residue of Tyr70 are expected to alter the binding behavior of the Loop1 of Fas2 with AChE.
Collapse
Affiliation(s)
- Jing Wang
- Computational Center for Molecular Structure and Interactions, Department of Chemistry, Jackson State University, Jackson, MS 39217, USA
| | | | | |
Collapse
|
5
|
Nirthanan S, Gwee MCE. Three-finger alpha-neurotoxins and the nicotinic acetylcholine receptor, forty years on. J Pharmacol Sci 2004; 94:1-17. [PMID: 14745112 DOI: 10.1254/jphs.94.1] [Citation(s) in RCA: 151] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
The discovery, about forty years ago, of alpha-bungarotoxin, a three-finger alpha-neurotoxin from Bungarus multicinctus venom, enabled the isolation of the nicotinic acetylcholine receptor (nAChR), making it one of the most thoroughly characterized receptors today. Since then, the sites of interaction between alpha-neurotoxins and nAChRs have largely been delineated, revealing the remarkable plasticity of the three-finger toxin fold that has optimally evolved to utilize different combinations of functional groups to generate a panoply of target specificities to discern subtle differences between nAChR subtypes. New facets in toxinology have now broadened the scope for the use of alpha-neurotoxins in scientific discovery. For instance, the development of short, combinatorial library-derived, synthetic peptides that bind with sub-nanomolar affinity to alpha-bungarotoxin and prevent its interaction with muscle nAChRs has led to the in vivo neutralization of experimental alpha-bungarotoxin envenomation, while the successful introduction of pharmatopes bearing "alpha-bungarotoxin-sensitive sites" into toxin-insensitive nAChRs has permitted the use of various alpha-neurotoxin tags to localize and characterize new receptor subtypes. More ambitious strategies can now be envisaged for engineering rationally designed novel activities on three-finger toxin scaffolds to generate lead peptides of therapeutic value that target the nicotinic pharmacopoeia. This review details the progress made towards achieving this goal.
Collapse
|
6
|
Lou X, Liu Q, Tu X, Wang J, Teng M, Niu L, Schuller DJ, Huang Q, Hao Q. The Atomic Resolution Crystal Structure of Atratoxin Determined by Single Wavelength Anomalous Diffraction Phasing. J Biol Chem 2004; 279:39094-104. [PMID: 15252034 DOI: 10.1074/jbc.m403863200] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
By using single wavelength anomalous diffraction phasing based on the anomalous signal from copper atoms, the crystal structure of atratoxin was determined at the resolution of 1.5 A and was refined to an ultrahigh resolution of 0.87 A. The ultrahigh resolution electron density maps allowed the modeling of 38 amino acid residues in alternate conformations and the location of 322 of 870 possible hydrogen atoms. To get accurate information at the atomic level, atratoxin-b (an analog of atratoxin with reduced toxicity) was also refined to an atomic resolution of 0.92 A. By the sequence and structural comparison of these two atratoxins, Arg(33) and Arg(36) were identified to be critical to their varied toxicity. The effect of copper ions on the distribution of hydrogen atoms in atratoxin was discussed, and the interactions between copper ions and protein residues were analyzed based on a statistical method, revealing a novel pentahedral copper-binding motif.
Collapse
Affiliation(s)
- Xiaohua Lou
- Key Laboratory of Structural Biology, Chinese Academy of Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China
| | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Gilquin B, Bourgoin M, Ménez R, Le Du MH, Servent D, Zinn-Justin S, Ménez A. Motions and structural variability within toxins: implication for their use as scaffolds for protein engineering. Protein Sci 2003; 12:266-77. [PMID: 12538890 PMCID: PMC2312431 DOI: 10.1110/ps.0227703] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Animal toxins are small proteins built on the basis of a few disulfide bonded frameworks. Because of their high variability in sequence and biologic function, these proteins are now used as templates for protein engineering. Here we report the extensive characterization of the structure and dynamics of two toxin folds, the "three-finger" fold and the short alpha/beta scorpion fold found in snake and scorpion venoms, respectively. These two folds have a very different architecture; the short alpha/beta scorpion fold is highly compact, whereas the "three-finger" fold is a beta structure presenting large flexible loops. First, the crystal structure of the snake toxin alpha was solved at 1.8-A resolution. Then, long molecular dynamics simulations (10 ns) in water boxes of the snake toxin alpha and the scorpion charybdotoxin were performed, starting either from the crystal or the solution structure. For both proteins, the crystal structure is stabilized by more hydrogen bonds than the solution structure, and the trajectory starting from the X-ray structure is more stable than the trajectory started from the NMR structure. The trajectories started from the X-ray structure are in agreement with the experimental NMR and X-ray data about the protein dynamics. Both proteins exhibit fast motions with an amplitude correlated to their secondary structure. In contrast, slower motions are essentially only observed in toxin alpha. The regions submitted to rare motions during the simulations are those that exhibit millisecond time-scale motions. Lastly, the structural variations within each fold family are described. The localization and the amplitude of these variations suggest that the regions presenting large-scale motions should be those tolerant to large insertions or deletions.
Collapse
Affiliation(s)
- Bernard Gilquin
- Département d'Ingénierie et d'Etude des Protéines, CEA, 91191 Gif sur Yvette, France.
| | | | | | | | | | | | | |
Collapse
|
8
|
Bouhaouala-Zahar B, Benkhalifa R, Srairi N, Zenouaki I, Ligny-Lemaire C, Drevet P, Sampieri F, Pelhate M, El Ayeb M, Ménez A, Karoui H, Ducancel F. A chimeric scorpion alpha-toxin displays de novo electrophysiological properties similar to those of alpha-like toxins. EUROPEAN JOURNAL OF BIOCHEMISTRY 2002; 269:2831-41. [PMID: 12071945 DOI: 10.1046/j.1432-1033.2002.02918.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BotXIV and LqhalphaIT are two structurally related long chain scorpion alpha-toxins that inhibit sodium current inactivation in excitable cells. However, while LqhalphaIT from Leiurus quinquestriatus hebraeus is classified as a true and strong insect alpha-toxin, BotXIV from Buthus occitanus tunetanus is characterized by moderate biological activities. To assess the possibility that structural differences between these two molecules could reflect the localization of particular functional topographies, we compared their sequences. Three structurally deviating segments located in three distinct and exposed loops were identified. They correspond to residues 8-10, 19-22, and 38-43. To evaluate their functional role, three BotXIV/LqhalphaIT chimeras were designed by transferring the corresponding LqhalphaIT sequences into BotXIV. Structural and antigenic characterizations of the resulting recombinant chimera show that BotXIV can accommodate the imposed modifications, confirming the structural flexibility of that particular alpha/beta fold. Interestingly, substitution of residues 8-10 yields to a new electrophysiological profile of the corresponding variant, partially comparable to that one of alpha-like scorpion toxins. Taken together, these results suggest that even limited structural deviations can reflect functional diversity, and also that the structure-function relationships between insect alpha-toxins and alpha-like scorpion toxins are probably more complex than expected.
Collapse
|
9
|
Cheng Y, Meng Q, Wang W, Wang J. Structure-function relationship of three neurotoxins from the venom of Naja kaouthia: a comparison between the NMR-derived structure of NT2 with its homologues, NT1 and NT3. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1594:353-63. [PMID: 11904231 DOI: 10.1016/s0167-4838(01)00326-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Three homologous short-chain neurotoxins, named NT1, NT2 and NT3, were purified from the venom of Naja kaouthia. NT1 has an identical amino acid sequence to cobrotoxin from Naja naja atra [Biochemistry 32 (1993) 2131]. NT3 shares the same sequence with cobrotoxin b [J. Biochem. (Tokyo) 122 (1997) 1252], whereas NT2 is a novel 61-residue neurotoxin. Tests of their physiological functions indicate that NT1 shows a greater inhibition of muscle contraction induced by electrical stimulation of the nerve than do NT2 and NT3. Homonuclear proton two-dimensional NMR methods were utilized to study the solution tertiary structure of NT2. A homology model-building method was employed to predict the structure of NT3. Comparison of the structures of these three toxins shows that the surface conformation of NT1 facilitates the substituted base residues, Arg28, Arg30, and Arg36, to occupy the favorable spatial location in the central region of loop II, and the cation groups of all three arginines face out of the molecular surface of NT1. This may contribute greatly to the higher binding of NT1 with AchR compared to NT2 and NT3.
Collapse
Affiliation(s)
- Yuan Cheng
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, PR China
| | | | | | | |
Collapse
|
10
|
Ricciardi A, le Du MH, Khayati M, Dajas F, Boulain JC, Menez A, Ducancel F. Do structural deviations between toxins adopting the same fold reflect functional differences? J Biol Chem 2000; 275:18302-10. [PMID: 10849442 DOI: 10.1074/jbc.275.24.18302] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Three-finger proteins form a structurally related family of compounds that exhibit a great variety of biological properties. To address the question of the prediction of functional areas on their surfaces, we tentatively conferred the acetylcholinesterase inhibitory activity of fasciculins on a short-chain curaremimetic toxin. For this purpose, we assimilated the three-dimensional structure of fasciculin 2 with the one of toxin alpha. This comparison revealed that the tips of the first and second loops, together with the C terminus residue, deviated most. A first recombinant fasciculin/toxin alpha chimera was designed by transferring loop 1 in its entirety together with the tip of loop 2 of fasciculin 2 into the toxin alpha scaffold. A second chimera (rChII) was obtained by adding the point Asn-61 --> Tyr substitution. Comparison of functional and structural properties of both chimeras show that rChII can accommodate the imposed modifications and displays nearly all the acetylcholinesterase-blocking activities of fasciculins. The three-dimensional structure of rChII demonstrates that rChII adopts a typical three-fingered fold with structural features of both parent toxins. Taken together, these results emphasize the great structural flexibility and functional adaptability of that fold and confirm that structural deviations between fasciculins and short-chain neurotoxins do indeed reflect functional diversity.
Collapse
Affiliation(s)
- A Ricciardi
- Instituto de Investigaciones Biologicas, Clemente Estable, Montevideo, Uruguay 11600, France
| | | | | | | | | | | | | |
Collapse
|