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Maeda S, Xu J, N Kadji FM, Clark MJ, Zhao J, Tsutsumi N, Aoki J, Sunahara RK, Inoue A, Garcia KC, Kobilka BK. Structure and selectivity engineering of the M 1 muscarinic receptor toxin complex. Science 2020; 369:161-167. [PMID: 32646996 DOI: 10.1126/science.aax2517] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Accepted: 04/21/2020] [Indexed: 12/13/2022]
Abstract
Muscarinic toxins (MTs) are natural toxins produced by mamba snakes that primarily bind to muscarinic acetylcholine receptors (MAChRs) and modulate their function. Despite their similar primary and tertiary structures, MTs show distinct binding selectivity toward different MAChRs. The molecular details of how MTs distinguish MAChRs are not well understood. Here, we present the crystal structure of M1AChR in complex with MT7, a subtype-selective anti-M1AChR snake venom toxin. The structure reveals the molecular basis of the extreme subtype specificity of MT7 for M1AChR and the mechanism by which it regulates receptor function. Through in vitro engineering of MT7 finger regions that was guided by the structure, we have converted the selectivity from M1AChR toward M2AChR, suggesting that the three-finger fold is a promising scaffold for developing G protein-coupled receptor modulators.
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Affiliation(s)
- Shoji Maeda
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA.
| | - Jun Xu
- Beijing Advanced Innovation Center for Structural Biology, School of Life Science, Tsinghua University, Beijing, China
| | | | - Mary J Clark
- Department of Pharmacology, University of California San Diego School of Medicine, La Jolla, CA 92093, USA
| | - Jiawei Zhao
- Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Naotaka Tsutsumi
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA.,Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.,Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Junken Aoki
- Graduate School of Pharmaceutical Science, Tohoku University, Sendai, Japan
| | - Roger K Sunahara
- Department of Pharmacology, University of California San Diego School of Medicine, La Jolla, CA 92093, USA
| | - Asuka Inoue
- Graduate School of Pharmaceutical Science, Tohoku University, Sendai, Japan
| | - K Christopher Garcia
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA.,Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.,Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Brian K Kobilka
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA. .,Beijing Advanced Innovation Center for Structural Biology, School of Life Science, Tsinghua University, Beijing, China
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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: 23] [Impact Index Per Article: 5.8] [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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cDNA Display of Disulfide-Containing Peptide Library and In Vitro Evolution. Methods Mol Biol 2019. [PMID: 31625090 DOI: 10.1007/978-1-4939-9853-1_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Directed in vitro evolution (IVE) is now a widely applied technology to obtain molecules that have designed new features of one's demands. We describe here experimental procedures for a cDNA display IVE to select peptide aptamers from a scaffold-based random peptide library. A three-finger (3-F) peptide library is exemplified, which has been shown its pluripotency to various target molecules. Peptide scaffolds including 3-F are refined through evolution, and they are mostly stabilized by disulfide bridges. To utilize such disulfide-containing protein library in IVE, we optimized the translation and folding conditions. Co-translational folding assisted by protein disulfide isomerase was found to have better efficiency than posttranslational refolding in the IVE. Linker is also a key element to make a tight genotype-phenotype linkage. Here, we introduced a whole procedure of IVE to use a newly designed puromycin linker, which was synthesized by a novel branching strategy. The improved linker enabled rapid and highly efficient ligation of mRNA and synthesis of protein fusions.
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Utkin YN. Last decade update for three-finger toxins: Newly emerging structures and biological activities. World J Biol Chem 2019; 10:17-27. [PMID: 30622682 PMCID: PMC6314878 DOI: 10.4331/wjbc.v10.i1.17] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 11/20/2018] [Accepted: 12/05/2018] [Indexed: 02/05/2023] Open
Abstract
Three-finger toxins (TFTs) comprise one of largest families of snake venom toxins. While they are principal to and the most toxic components of the venoms of the Elapidae snake family, their presence has also been detected in the venoms of snakes from other families. The first TFT, α-bungarotoxin, was discovered almost 50 years ago and has since been used widely as a specific marker of the α7 and muscle-type nicotinic acetylcholine receptors. To date, the number of TFT amino acid sequences deposited in the UniProt Knowledgebase free-access database is more than 700, and new members are being added constantly. Although structural variations among the TFTs are not numerous, several new structures have been discovered recently; these include the disulfide-bound dimers of TFTs and toxins with nonstandard pairing of disulfide bonds. New types of biological activities have also been demonstrated for the well-known TFTs, and research on this topic has become a hot topic of TFT studies. The classic TFTs α-bungarotoxin and α-cobratoxin, for example, have now been shown to inhibit ionotropic receptors of γ-aminobutyric acid, and some muscarinic toxins have been shown to interact with adrenoceptors. New, unexpected activities have been demonstrated for some TFTs as well, such as toxin interaction with interleukin or insulin receptors and even TFT-activated motility of sperm. This minireview provides a summarization of the data that has emerged in the last decade on the TFTs and their activities.
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Affiliation(s)
- Yuri N Utkin
- Laboratory of Molecular Toxinology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow 117997, Russia
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Ancestral protein resurrection and engineering opportunities of the mamba aminergic toxins. Sci Rep 2017; 7:2701. [PMID: 28578406 PMCID: PMC5457417 DOI: 10.1038/s41598-017-02953-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 04/25/2017] [Indexed: 12/17/2022] Open
Abstract
Mamba venoms contain a multiplicity of three-finger fold aminergic toxins known to interact with various α-adrenergic, muscarinic and dopaminergic receptors with different pharmacological profiles. In order to generate novel functions on this structural scaffold and to avoid the daunting task of producing and screening an overwhelming number of variants generated by a classical protein engineering strategy, we accepted the challenge of resurrecting ancestral proteins, likely to have possessed functional properties. This innovative approach that exploits molecular evolution models to efficiently guide protein engineering, has allowed us to generate a small library of six ancestral toxin (AncTx) variants and associate their pharmacological profiles to key functional substitutions. Among these variants, we identified AncTx1 as the most α1A-adrenoceptor selective peptide known to date and AncTx5 as the most potent inhibitor of the three α2 adrenoceptor subtypes. Three positions in the ρ-Da1a evolutionary pathway, positions 28, 38 and 43 have been identified as key modulators of the affinities for the α1 and α2C adrenoceptor subtypes. Here, we present a first attempt at rational engineering of the aminergic toxins, revealing an epistasis phenomenon.
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Mochizuki Y, Suzuki T, Fujimoto K, Nemoto N. A versatile puromycin-linker using cnvK for high-throughput in vitro selection by cDNA display. J Biotechnol 2015; 212:174-80. [DOI: 10.1016/j.jbiotec.2015.08.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Revised: 08/20/2015] [Accepted: 08/24/2015] [Indexed: 01/04/2023]
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