1
|
Huang Q, Chu X, Zhang H, Yu S, Zhang L, Zhang X, Yu R, Guo C, Dai Q. Discovery and Structural and Functional Characterization of a Novel A-Superfamily Conotoxin Targeting α9α10 Nicotinic Acetylcholine Receptor. ACS Chem Biol 2022; 17:2483-2494. [PMID: 36048451 DOI: 10.1021/acschembio.2c00315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Nicotinic acetylcholine receptors (nAChRs) are pentameric ligand-gated ion channels widely distributed in the central peripheral nervous system and muscles which participate in rapid synaptic transmission. The α9α10 nAChR is an acetylcholine receptor subtype and is involved in chronic pain. In the present study, a new A-superfamily conotoxin Bt14.12 cloned from Conus betulinus was found to selectively inhibit α9α10 nAChRs with an IC50 of 62.3 nM. Unlike α-conotoxins and other A-superfamily conotoxins, Bt14.12 contains a four Cys (C-C-C-C) framework with a unique disulfide bond connection "C1-C4, C2-C3". The structure-activity studies of Bt14.12 demonstrate that all amino acid residues contribute to its potency. Interestingly, mutation experiments show that the deletion of Asp2 or the addition of three Arg residues at the N-terminus of Bt14.12 significantly enhances its inhibitory activity (IC50 is 21.9 nM or 12.7 nM, respectively) by 2- or 4-fold compared to the wild-type Bt14.12. The NMR structure of Bt14.12 shows that it contains α-helix- and β-turn-like elements, and further computational modelings of the interaction between Bt14.12 and the α9α10 nAChR demonstrate that Bt14.12 possesses a distinctive mode of action and displays a different structure-activity relationship from known α9α10 nAChR targeting α-conotoxins. Our findings provide a novel conotoxin that potently targets α9α10 nAChRs and a new motif for designing potent inhibitors against α9α10 nAChRs.
Collapse
Affiliation(s)
- Qiuyuan Huang
- Beijing Institute of Biotechnology, Beijing 100071, China.,Life Sciences Institute of Guangxi Medical University, Nanning, Guangxi 530021, China
| | - Xin Chu
- Beijing Institute of Biotechnology, Beijing 100071, China.,Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
| | - Haoran Zhang
- Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Shuo Yu
- Beijing Institute of Biotechnology, Beijing 100071, China
| | - Longxiao Zhang
- Beijing Institute of Biotechnology, Beijing 100071, China
| | - Xuerong Zhang
- Life Sciences Institute of Guangxi Medical University, Nanning, Guangxi 530021, China
| | - Rilei Yu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
| | - Chenyun Guo
- Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Qiuyun Dai
- Beijing Institute of Biotechnology, Beijing 100071, China
| |
Collapse
|
2
|
Marine Origin Ligands of Nicotinic Receptors: Low Molecular Compounds, Peptides and Proteins for Fundamental Research and Practical Applications. Biomolecules 2022; 12:biom12020189. [PMID: 35204690 PMCID: PMC8961598 DOI: 10.3390/biom12020189] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/18/2022] [Accepted: 01/19/2022] [Indexed: 02/05/2023] Open
Abstract
The purpose of our review is to briefly show what different compounds of marine origin, from low molecular weight ones to peptides and proteins, offer for understanding the structure and mechanism of action of nicotinic acetylcholine receptors (nAChRs) and for finding novel drugs to combat the diseases where nAChRs may be involved. The importance of the mentioned classes of ligands has changed with time; a protein from the marine snake venom was the first excellent tool to characterize the muscle-type nAChRs from the electric ray, while at present, muscle and α7 receptors are labeled with the radioactive or fluorescent derivatives prepared from α-bungarotoxin isolated from the many-banded krait. The most sophisticated instruments to distinguish muscle from neuronal nAChRs, and especially distinct subtypes within the latter, are α-conotoxins. Such information is crucial for fundamental studies on the nAChR revealing the properties of their orthosteric and allosteric binding sites and mechanisms of the channel opening and closure. Similar data are provided by low-molecular weight compounds of marine origin, but here the main purpose is drug design. In our review we tried to show what has been obtained in the last decade when the listed classes of compounds were used in the nAChR research, applying computer modeling, synthetic analogues and receptor mutants, X-ray and electron-microscopy analyses of complexes with the nAChRs, and their models which are acetylcholine-binding proteins and heterologously-expressed ligand-binding domains.
Collapse
|
3
|
Fouda MMA, Abdel-Wahab M, Mohammadien A, Germoush MO, Sarhan M. Proteomic analysis of Red Sea Conus taeniatus venom reveals potential biological applications. J Venom Anim Toxins Incl Trop Dis 2021; 27:e20210023. [PMID: 34712278 PMCID: PMC8525892 DOI: 10.1590/1678-9199-jvatitd-2021-0023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 05/12/2021] [Indexed: 11/26/2022] Open
Abstract
Background: Diverse and unique bioactive neurotoxins known as conopeptides or conotoxins
are produced by venomous marine cone snails. Currently, these small and
stable molecules are of great importance as research tools and platforms for
discovering new drugs and therapeutics. Therefore, the characterization of
Conus venom is of great significance, especially for
poorly studied species. Methods: In this study, we used bioanalytical techniques to determine the venom
profile and emphasize the functional composition of conopeptides in
Conus taeniatus, a neglected worm-hunting cone snail.
Results: The proteomic analysis revealed that 84.0% of the venom proteins were between
500 and 4,000 Da, and 16.0% were > 4,000 Da. In C.
taeniatus venom, 234 peptide fragments were identified and
classified as conotoxin precursors or non-conotoxin proteins. In this
process, 153 conotoxin precursors were identified and matched to 23
conotoxin precursors and hormone superfamilies. Notably, the four conotoxin
superfamilies T (22.87%), O1 (17.65%), M (13.1%) and O2 (9.8%) were the most
abundant peptides in C. taeniatus venom, accounting for
63.40% of the total conotoxin diversity. On the other hand, 48 non-conotoxin
proteins were identified in the venom of C. taeniatus.
Moreover, several possibly biologically active peptide matches were
identified, and putative applications of the peptides were assigned. Conclusion: Our study showed that the composition of the C.
taeniatus-derived proteome is comparable to that of other
Conus species and contains an effective mix of toxins,
ionic channel inhibitors and antimicrobials. Additionally, it provides a
guidepost for identifying novel conopeptides from the venom of C.
taeniatus and discovering conopeptides of potential
pharmaceutical importance.
Collapse
Affiliation(s)
- Maged M A Fouda
- Department of Biology, College of Science, Jouf University, Saudi Arabia.,Zoology Department, Faculty of Science, Al-Azhar University, Assiut, Egypt
| | | | - Amal Mohammadien
- Department of Biology, College of Science, Taeif University, Saudi Arabia.,Zoology Department, Faculty of Science, Zagazig University, Zagazig, Egypt
| | - Mousa O Germoush
- Department of Biology, College of Science, Jouf University, Saudi Arabia
| | - Moustafa Sarhan
- Zoology Department, Faculty of Science, Al-Azhar University, Assiut, Egypt
| |
Collapse
|
4
|
Oroz-Parra I, Álvarez-Delgado C, Cervantes-Luevano K, Dueñas-Espinoza S, Licea-Navarro AF. Proapoptotic Index Evaluation of Two Synthetic Peptides Derived from the Coneshell Californiconus californicus in Lung Cancer Cell Line H1299. Mar Drugs 2019; 18:md18010010. [PMID: 31861952 PMCID: PMC7024154 DOI: 10.3390/md18010010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 12/15/2019] [Accepted: 12/18/2019] [Indexed: 02/07/2023] Open
Abstract
Lung cancer is one of the most common types of cancer, accounting for approximately 15% of all cancer cases worldwide. Apoptosis is the dominant defense mechanism against tumor development. The balance between pro- and antiapoptotic members of the Bcl-2 protein family can determine cellular fate. The venom of predatory marine snails Conus is estimated to have 100-400 toxins called conotoxins. The family of α-conotoxins is known to consist of selective antagonists of nicotinic acetylcholine receptors (nAChRs). Lung cancer cells overexpress several subunits of nAChRs and are considered as an excellent target for new anticancer drugs. We compared the cytotoxic effect of two synthetic peptides derived from Californiconus californicus, Cal14.1a, and Cal14.1b, which only differ by one amino acid in their sequence, and compared their proapoptotic balance by Bax and Bcl-2 mRNA expression. We determined the caspase-3 and -7 activation to demonstrate apoptosis induction. Results showed that Cal14.1a induces a high Bax/Bcl-2 ratio in H1299 (lung cancer cells). Although Cal14.1b has a cytotoxic effect on H1299 cells, reducing cell viability by 30%, it does not increase the Bax/Bcl-2 ratio, which could be explained by the Glu in the 15th residue, which is crucial for the ability of Cal14.1a to induce apoptosis.
Collapse
Affiliation(s)
- Irasema Oroz-Parra
- Facultad de Ciencias Marinas, Universidad Autónoma de Baja California (UABC), Ensenada 22860, Baja California, Mexico;
- Departamento de Innovación Biomédica, Centro de Investigación y de Educación Superior de Ensenada (CICESE), Ensenada 22860, Baja California, Mexico (K.C.-L.); (S.D.-E.)
| | - Carolina Álvarez-Delgado
- Departamento de Innovación Biomédica, Centro de Investigación y de Educación Superior de Ensenada (CICESE), Ensenada 22860, Baja California, Mexico (K.C.-L.); (S.D.-E.)
| | - Karla Cervantes-Luevano
- Departamento de Innovación Biomédica, Centro de Investigación y de Educación Superior de Ensenada (CICESE), Ensenada 22860, Baja California, Mexico (K.C.-L.); (S.D.-E.)
| | - Salvador Dueñas-Espinoza
- Departamento de Innovación Biomédica, Centro de Investigación y de Educación Superior de Ensenada (CICESE), Ensenada 22860, Baja California, Mexico (K.C.-L.); (S.D.-E.)
| | - Alexei F. Licea-Navarro
- Departamento de Innovación Biomédica, Centro de Investigación y de Educación Superior de Ensenada (CICESE), Ensenada 22860, Baja California, Mexico (K.C.-L.); (S.D.-E.)
- Correspondence: ; Tel.: +52-646-1750500
| |
Collapse
|
5
|
Fu Y, Li C, Dong S, Wu Y, Zhangsun D, Luo S. Discovery Methodology of Novel Conotoxins from Conus Species. Mar Drugs 2018; 16:md16110417. [PMID: 30380764 PMCID: PMC6266589 DOI: 10.3390/md16110417] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Revised: 10/21/2018] [Accepted: 10/25/2018] [Indexed: 12/17/2022] Open
Abstract
Cone snail venoms provide an ideal resource for neuropharmacological tools and drug candidates discovery, which have become a research hotspot in neuroscience and new drug development. More than 1,000,000 natural peptides are produced by cone snails, but less than 0.1% of the estimated conotoxins has been characterized to date. Hence, the discovery of novel conotoxins from the huge conotoxin resources with high-throughput and sensitive methods becomes a crucial key for the conotoxin-based drug development. In this review, we introduce the discovery methodology of new conotoxins from various Conus species. It focuses on obtaining full N- to C-terminal sequences, regardless of disulfide bond connectivity through crude venom purification, conotoxin precusor gene cloning, venom duct transcriptomics, venom proteomics and multi-omic methods. The protocols, advantages, disadvantages, and developments of different approaches during the last decade are summarized and the promising prospects are discussed as well.
Collapse
Affiliation(s)
- Ying Fu
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Hainan University, Haikou 570228, China.
| | - Cheng Li
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Hainan University, Haikou 570228, China.
| | - Shuai Dong
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Hainan University, Haikou 570228, China.
| | - Yong Wu
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Hainan University, Haikou 570228, China.
| | - Dongting Zhangsun
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Hainan University, Haikou 570228, China.
| | - Sulan Luo
- Key Laboratory for Marine Drugs of Haikou, Hainan University, Haikou 570228, China.
| |
Collapse
|
6
|
Ren J, Li R, Ning J, Zhu X, Zhangsun D, Wu Y, Luo S. Effect of Methionine Oxidation and Substitution of α-Conotoxin TxID on α3β4 Nicotinic Acetylcholine Receptor. Mar Drugs 2018; 16:md16060215. [PMID: 29925760 PMCID: PMC6025358 DOI: 10.3390/md16060215] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 06/05/2018] [Accepted: 06/15/2018] [Indexed: 12/24/2022] Open
Abstract
α-Conotoxin TxID was discovered from Conus textile by gene cloning, which has 4/6 inter-cysteine loop spacing and selectively inhibits α3β4 nicotinic acetylcholine receptor (nAChR) subtype. However, TxID is susceptible to modification due to it containing a methionine (Met) residue that easily forms methionine sulfoxide (MetO) in oxidative environment. In this study, we investigated how Met-11 and its derivatives affect the activity of TxID using a combination of electrophysiological recordings and molecular modelling. The results showed most TxID analogues had substantially decreased activities on α3β4 nAChR with more than 10-fold potency loss and 5 of them demonstrated no inhibition on α3β4 nAChR. However, one mutant, [M11I]TxID, displayed potent inhibition at α3β4 nAChR with an IC50 of 69 nM, which only exhibited 3.8-fold less compared with TxID. Molecular dynamics simulations were performed to expound the decrease in the affinity for α3β4 nAChR. The results indicate replacement of Met with a hydrophobic moderate-sized Ile in TxID is an alternative strategy to reduce the impact of Met oxidation, which may help to redesign conotoxins containing methionine residue.
Collapse
Affiliation(s)
- Jie Ren
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Key Laboratory for Marine Drugs of Haikou, Hainan University, Haikou 570228, China.
- Institute of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China.
| | - Rui Li
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Key Laboratory for Marine Drugs of Haikou, Hainan University, Haikou 570228, China.
| | - Jiong Ning
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Key Laboratory for Marine Drugs of Haikou, Hainan University, Haikou 570228, China.
| | - Xiaopeng Zhu
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Key Laboratory for Marine Drugs of Haikou, Hainan University, Haikou 570228, China.
| | - Dongting Zhangsun
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Key Laboratory for Marine Drugs of Haikou, Hainan University, Haikou 570228, China.
| | - Yong Wu
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Key Laboratory for Marine Drugs of Haikou, Hainan University, Haikou 570228, China.
| | - Sulan Luo
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Key Laboratory for Marine Drugs of Haikou, Hainan University, Haikou 570228, China.
| |
Collapse
|
7
|
Dutertre S, Nicke A, Tsetlin VI. Nicotinic acetylcholine receptor inhibitors derived from snake and snail venoms. Neuropharmacology 2017. [PMID: 28623170 DOI: 10.1016/j.neuropharm.2017.06.011] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The nicotinic acetylcholine receptor (nAChR) represents the prototype of ligand-gated ion channels. It is vital for neuromuscular transmission and an important regulator of neurotransmission. A variety of toxic compounds derived from diverse species target this receptor and have been of elemental importance in basic and applied research. They enabled milestone discoveries in pharmacology and biochemistry ranging from the original formulation of the receptor concept, the first isolation and structural analysis of a receptor protein (the nAChR) to the identification, localization, and differentiation of its diverse subtypes and their validation as a target for therapeutic intervention. Among the venom-derived compounds, α-neurotoxins and α-conotoxins provide the largest families and still represent indispensable pharmacological tools. Application of modified α-neurotoxins provided substantial structural and functional details of the nAChR long before high resolution structures were available. α-bungarotoxin represents not only a standard pharmacological tool and label in nAChR research but also for unrelated proteins tagged with a minimal α-bungarotoxin binding motif. A major advantage of α-conotoxins is their smaller size, as well as superior selectivity for diverse nAChR subtypes that allows their development into ligands with optimized pharmacological and chemical properties and potentially novel drugs. In the following, these two groups of nAChR antagonists will be described focusing on their respective roles in the structural and functional characterization of nAChRs and their development into research tools. In addition, we provide a comparative overview of the diverse α-conotoxin selectivities that can serve as a practical guide for both structure activity studies and subtype classification. This article is part of the Special Issue entitled 'Venom-derived Peptides as Pharmacological Tools.'
Collapse
Affiliation(s)
- Sébastien Dutertre
- Institut des Biomolécules Max Mousseron, UMR 5247, Université Montpellier - CNRS, Place Eugène Bataillon, 34095 Montpellier Cedex 5, France
| | - Annette Nicke
- Walther Straub Institute for Pharmacology and Toxicology, Ludwig-Maximilians-Universität, Nußbaumstr. 26, 80336 Munich, Germany.
| | - Victor I Tsetlin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya str.16/10, Moscow 117999, Russian Federation
| |
Collapse
|
8
|
Yu S, Du T, Liu Z, Wu Q, Feng G, Dong M, Zhou X, Jiang L, Dai Q. Im10A, a short conopeptide isolated from Conus imperialis and possesses two highly concentrated disulfide bridges and analgesic activity. Peptides 2016; 81:15-20. [PMID: 27131596 DOI: 10.1016/j.peptides.2016.04.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 04/02/2016] [Accepted: 04/26/2016] [Indexed: 12/27/2022]
Abstract
In the present study, we isolated, synthesized and NMR structurally characterized a novel conopeptide Im10A consisting of 11 amino acids (NTICCEGCMCY-NH2) from Conus imperialis. Unlike other conopeptides with four cysteine residues, Im10A had only two residues in loop 1 and one residue in loop 2 (CC-loop1-C-loop2-C), which formed a stable disulfide connectivity "I-IV, II- III" (framework X) with a type I β-turn. Interestingly, Im10A exhibited 50.7% analgesic activity on rat partial sciatic nerve ligation (PNL) at 2h after Im10A administration. However, 10μM Im10A exhibited no apparent effect on neuronal nicotinic acetylcholine receptor, and it did not target DRG voltage-dependent sodium, potassium and calcium ion channels and opioid receptor. To our knowledge, Im10A had the most concentrated disulfide bridges among conopeptides with four cysteine residues. This finding provided a new motif for the future development of biomimetic compounds.
Collapse
Affiliation(s)
- Shuo Yu
- Beijing Institute of Biotechnology, Beijing 10071, PR China
| | - Tianpeng Du
- Key Laboratory of Magnetic Resonance in Biological Systems, National Center for Magnetic Resonance in Wuhan, State Key laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Science, Wuhan 430071, PR China
| | - Zhuguo Liu
- Beijing Institute of Biotechnology, Beijing 10071, PR China
| | - Qiaoling Wu
- Beijing Institute of Biotechnology, Beijing 10071, PR China
| | - Guixue Feng
- Beijing Institute of Biotechnology, Beijing 10071, PR China
| | - Mingxin Dong
- Beijing Institute of Biotechnology, Beijing 10071, PR China
| | - Xiaowei Zhou
- Beijing Institute of Biotechnology, Beijing 10071, PR China
| | - Ling Jiang
- Key Laboratory of Magnetic Resonance in Biological Systems, National Center for Magnetic Resonance in Wuhan, State Key laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Science, Wuhan 430071, PR China.
| | - Qiuyun Dai
- Beijing Institute of Biotechnology, Beijing 10071, PR China.
| |
Collapse
|
9
|
Christensen SB, Bandyopadhyay PK, Olivera BM, McIntosh JM. αS-conotoxin GVIIIB potently and selectively blocks α9α10 nicotinic acetylcholine receptors. Biochem Pharmacol 2015; 96:349-56. [PMID: 26074268 DOI: 10.1016/j.bcp.2015.06.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 06/05/2015] [Indexed: 11/18/2022]
Abstract
Although acetylcholine is widely utilized in vertebrate nervous systems, nicotinic acetylcholine receptors (nAChRs), including the α9α10 subtype, also are expressed in a wide variety of non-neuronal cells. These cell types include cochlear hair cells, adrenal chromaffin cells and immune cells. α9α10 nAChRs present in these cells may respectively play roles in protection from noise-induced hearing loss, response to stress and neuroprotection. Despite these critical functions, there are few available selective ligands to confirm mechanistic hypothesis regarding the role of α9α10 nAChRs. Conus, has been a rich source of ligands for receptors and ion channels. Here, we identified Conus geographus venom as a lead source for a novel α9α10 antagonist. The active component was isolated and the encoding gene cloned. The peptide signal sequence and cysteine arrangement had the signature of the σ-conotoxin superfamily. Previously isolated σ-conotoxin GVIIIA, also from Conus geographus, targets the 5-HT3 receptor. In contrast, αS-GVIIIB blocked the α9α10 nAChR with an IC50 of 9.8 nM, yet was inactive at the 5-HT3 receptor. Pharmacological characterization of αS-GVIIIB shows that it is over 100-fold selective for the α9α10 nAChR compared to other nAChR subtypes. Thus, the S-superfamily represents a novel conotoxin scaffold for flexibly targeting a variety of receptor subtypes. Functional competition studies utilized distinct off-rate kinetics of conotoxins to identify the α10/α9 nAChR interface as the site of αS-GVIIIB binding; this adds to the importance of the (+) face of the α10 rather than the (+) face of the α9 nAChR subunit as critical to binding of α9α10-targeted conotoxins.
Collapse
Affiliation(s)
- Sean B Christensen
- Department of Biology, University of Utah, Salt Lake City, UT 84112, USA
| | | | | | - J Michael McIntosh
- Department of Biology, University of Utah, Salt Lake City, UT 84112, USA; George E. Wahlen Veterans Affairs Medical Center, Salt Lake City, UT 84108, USA; Department of Psychiatry, University of Utah, Salt Lake City, UT 84112, USA.
| |
Collapse
|
10
|
Natural compounds interacting with nicotinic acetylcholine receptors: from low-molecular weight ones to peptides and proteins. Toxins (Basel) 2015; 7:1683-701. [PMID: 26008231 PMCID: PMC4448168 DOI: 10.3390/toxins7051683] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Accepted: 05/07/2015] [Indexed: 12/16/2022] Open
Abstract
Nicotinic acetylcholine receptors (nAChRs) fulfill a variety of functions making identification and analysis of nAChR subtypes a challenging task. Traditional instruments for nAChR research are d-tubocurarine, snake venom protein α-bungarotoxin (α-Bgt), and α-conotoxins, neurotoxic peptides from Conus snails. Various new compounds of different structural classes also interacting with nAChRs have been recently identified. Among the low-molecular weight compounds are alkaloids pibocin, varacin and makaluvamines C and G. 6-Bromohypaphorine from the mollusk Hermissenda crassicornis does not bind to Torpedo nAChR but behaves as an agonist on human α7 nAChR. To get more selective α-conotoxins, computer modeling of their complexes with acetylcholine-binding proteins and distinct nAChRs was used. Several novel three-finger neurotoxins targeting nAChRs were described and α-Bgt inhibition of GABA-A receptors was discovered. Information on the mechanisms of nAChR interactions with the three-finger proteins of the Ly6 family was found. Snake venom phospholipases A2 were recently found to inhibit different nAChR subtypes. Blocking of nAChRs in Lymnaea stagnalis neurons was shown for venom C-type lectin-like proteins, appearing to be the largest molecules capable to interact with the receptor. A huge nAChR molecule sensible to conformational rearrangements accommodates diverse binding sites recognizable by structurally very different compounds.
Collapse
|
11
|
Conotoxin gene superfamilies. Mar Drugs 2014; 12:6058-101. [PMID: 25522317 PMCID: PMC4278219 DOI: 10.3390/md12126058] [Citation(s) in RCA: 130] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 11/29/2014] [Accepted: 12/04/2014] [Indexed: 12/16/2022] Open
Abstract
Conotoxins are the peptidic components of the venoms of marine cone snails (genus Conus). They are remarkably diverse in terms of structure and function. Unique potency and selectivity profiles for a range of neuronal targets have made several conotoxins valuable as research tools, drug leads and even therapeutics, and has resulted in a concerted and increasing drive to identify and characterise new conotoxins. Conotoxins are translated from mRNA as peptide precursors, and cDNA sequencing is now the primary method for identification of new conotoxin sequences. As a result, gene superfamily, a classification based on precursor signal peptide identity, has become the most convenient method of conotoxin classification. Here we review each of the described conotoxin gene superfamilies, with a focus on the structural and functional diversity present in each. This review is intended to serve as a practical guide to conotoxin superfamilies and to facilitate interpretation of the increasing number of conotoxin precursor sequences being identified by targeted-cDNA sequencing and more recently high-throughput transcriptome sequencing.
Collapse
|
12
|
Kövér KE, Batta G. NMR investigation of disulfide containing peptides and proteins. AMINO ACIDS, PEPTIDES AND PROTEINS 2013:37-59. [DOI: 10.1039/9781849737081-00037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
Abstract
Peptides and proteins with disulfide bonds are abundant in all kingdoms and play essential role in many biological events. Because small disulfide-rich peptides (proteins) are usually difficult to crystallize, nuclear magnetic resonance (NMR) is by far one of the most powerful techniques for the determination of their solution structure. Besides the “static” three-dimensional structure, NMR has unique opportunities to acquire additional information about molecular dynamics and folding at atomic resolution. Nowadays it is becoming increasingly evident, that “excited”, “disordered” or “fuzzy” protein states may exhibit biological function and disulfide proteins are also promising targets for such studies. In this short two-three years overview those disulfide peptides and proteins were cited from the literature that were studied by NMR. Though we may have missed some, their structural diversity and complexity as well as their wide repertoire of biological functions is impressive. We emphasised especially antimicrobial peptides and peptide based toxins in addition to some biologically important other structures. Besides the general NMR methods we reviewed some contemporary techniques suitable for disclosing the peculiar properties of disulfide bonds. Interesting dynamics and folding studies of disulfide proteins were also mentioned. It is important to disclose the essential structure, dynamics, function aspects of disulfide proteins since this aids the design of new compounds with improved activity and reduced toxicity. Undoubtedly, NMR has the potential to accelerate the development of new disulfide peptides/proteins with pharmacological activity.
Collapse
|
13
|
Neves J, Campos A, Osório H, Antunes A, Vasconcelos V. Conopeptides from Cape Verde Conus crotchii. Mar Drugs 2013; 11:2203-15. [PMID: 23783403 PMCID: PMC3721229 DOI: 10.3390/md11062203] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Revised: 05/20/2013] [Accepted: 05/27/2013] [Indexed: 12/11/2022] Open
Abstract
Marine Cone snails of the genus Conus contain complex peptide toxins in their venom. Living in tropical habitats, they usually use the powerful venom for self-defense and prey capture. Here, we study Conus crotchii venom duct using a peptide mass-matching approach. The C. crotchii was collected on the Cape Verde archipelago in the Boa Vista Island. The venom was analyzed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). About 488 molecular masses between 700 Da and 3000 Da were searched bymatching with known peptide sequences from UniProtKB protein sequence database. Through this method we were able to identify 12 conopeptides. For validation we considered the error between the experimental molecular mass (monoisotopic) and the calculated mass of less than 0.5 Da. All conopeptides detected belong to the A-, O1-, O2-, O3-, T- and D-superfamilies, which can block Ca²⁺ channels, inhibit K⁺ channels and act on nicotinic acetylcholine receptors (nAChRs). Only a few of the detected peptides have a 100% UniProtKB database similarity, suggesting that several of them could be newly discovered marine drugs.
Collapse
Affiliation(s)
- Jorge Neves
- CIIMAR/CIMAR—Interdisciplinary Centre of Marine and Environmental Research, Rua dos Bragas 289, Porto 4050-123, Portugal; E-Mails: (J.N.); (A.C.); (A.A.)
- DECM—Department of Engineering and Sea Science, Cape Verde University, Mindelo CP 163, Cape Verde
| | - Alexandre Campos
- CIIMAR/CIMAR—Interdisciplinary Centre of Marine and Environmental Research, Rua dos Bragas 289, Porto 4050-123, Portugal; E-Mails: (J.N.); (A.C.); (A.A.)
| | - Hugo Osório
- Institute of Molecular Pathology and Immunology of the University of Porto, IPATIMUP, Porto 4200-465, Portugal; E-Mail:
- Faculty of Medicine, University of Porto, Porto 4200-319, Portugal
| | - Agostinho Antunes
- CIIMAR/CIMAR—Interdisciplinary Centre of Marine and Environmental Research, Rua dos Bragas 289, Porto 4050-123, Portugal; E-Mails: (J.N.); (A.C.); (A.A.)
- Faculty of Sciences, University of Porto, Porto 4169-007, Portugal
| | - Vitor Vasconcelos
- CIIMAR/CIMAR—Interdisciplinary Centre of Marine and Environmental Research, Rua dos Bragas 289, Porto 4050-123, Portugal; E-Mails: (J.N.); (A.C.); (A.A.)
- Faculty of Sciences, University of Porto, Porto 4169-007, Portugal
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +351-22-340-1817; Fax: +351-22-339-0608
| |
Collapse
|
14
|
Dobson R, Collodoro M, Gilles N, Turtoi A, De Pauw E, Quinton L. Secretion and maturation of conotoxins in the venom ducts of Conus textile. Toxicon 2012; 60:1370-9. [PMID: 23031820 DOI: 10.1016/j.toxicon.2012.09.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Revised: 08/31/2012] [Accepted: 09/04/2012] [Indexed: 11/29/2022]
Abstract
The 700 or more species of cone snail attack prey by employing complex venom which can vary considerably both within species and from one species to another. Cone snail venom is remarkable for the high proportion of conotoxins with varied post-translational modifications (PTMs) and for the production of more diverse toxin scaffolds than any other known venomous animal. The venom gland, which is several times longer than its shell, is also unique in being tubular. These unusual characteristics both raise questions, and provide the opportunity for research, concerning the secretion and maturation of conotoxins along the venom duct, a process which is currently not fully understood. This research uses the two mass spectrometric techniques of isotope Coded Affinity Tagging (ICAT) and label-free quantification to study each of five portions of the venom duct of Conus textile snails from New Caledonia. Fifteen conotoxins, several with different post-translational modifications (PTMs) were identified and quantified. One hundred and forty three non-identified conotoxins were also quantified. Distinctive patterns emerged, with the largest group of conotoxins increasing, then peaking in the central-proximal part, before decreasing; whilst the second largest group peaked in the distal region, generally displaying nothing in the first parts. Conotoxins from different superfamilies were commonly found to have similar distributions. A new conotoxin, PCCSKLHDNSCCGL*, was sequenced. A comparison is made with other studies to see how the process varies in cone snails from different regions.
Collapse
Affiliation(s)
- Rowan Dobson
- Laboratory of Mass Spectrometry, Department of Chemistry, University of Liege, Liege, Belgium
| | | | | | | | | | | |
Collapse
|
15
|
Conotoxins that confer therapeutic possibilities. Mar Drugs 2012; 10:1244-1265. [PMID: 22822370 PMCID: PMC3397437 DOI: 10.3390/md10061244] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 04/24/2012] [Accepted: 05/24/2012] [Indexed: 12/19/2022] Open
Abstract
Cone snails produce a distinctive repertoire of venom peptides that are used both as a defense mechanism and also to facilitate the immobilization and digestion of prey. These peptides target a wide variety of voltage- and ligand-gated ion channels, which make them an invaluable resource for studying the properties of these ion channels in normal and diseased states, as well as being a collection of compounds of potential pharmacological use in their own right. Examples include the United States Food and Drug Administration (FDA) approved pharmaceutical drug, Ziconotide (Prialt®; Elan Pharmaceuticals, Inc.) that is the synthetic equivalent of the naturally occurring ω-conotoxin MVIIA, whilst several other conotoxins are currently being used as standard research tools and screened as potential therapeutic drugs in pre-clinical or clinical trials. These developments highlight the importance of driving conotoxin-related research. A PubMed query from 1 January 2007 to 31 August 2011 combined with hand-curation of the retrieved articles allowed for the collation of 98 recently identified conotoxins with therapeutic potential which are selectively discussed in this review. Protein sequence similarity analysis tentatively assigned uncharacterized conotoxins to predicted functional classes. Furthermore, conotoxin therapeutic potential for neurodegenerative disorders (NDD) was also inferred.
Collapse
|
16
|
Zhang B, Huang F, Du W. Solution structure of a novel α-conotoxin with a distinctive loop spacing pattern. Amino Acids 2011; 43:389-96. [PMID: 21968500 DOI: 10.1007/s00726-011-1093-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Accepted: 09/19/2011] [Indexed: 11/30/2022]
Abstract
α-Pharmacological conotoxins are among the most selective ligands of nicotinic acetylcholine receptors with typical cysteine frameworks. They are characterized by the intercysteine loop and classified into various subfamilies, such as α3/5 and α4/7 conotoxins. A novel α-conotoxin, Pu14a (DCPPHPVPGMHKCVCLKTC), with a distinct loop spacing pattern between cysteines was reported recently. Pu14a belongs to the Cys framework 14 (-C-C-C-C) family containing four proline residues in the loop 1 region. Similar to another framework 14 conotoxin Lt14a (MCPPLCKPSCTNC-NH2), Pu14a has C1-C3/C2-C4 disulfide linkage, and can inhibit some subtypes of nicotinic acetylcholine receptors. In this study, the solution structure of Pu14a was investigated using 1H nuclear magnetic resonance spectroscopy to understand the structure-activity relationship of this conotoxin. 20 converged structures of this conopeptide, with RMSD value of 0.77 Å, were obtained based on distance constraints, dihedral angles and disulfide bond constraints. The three-dimensional structure of Pu14a showed remarkable difference from typical α-conotoxins because of a large intercysteine loop between C2 and C13, as well as a 3(10)-helix near the C-terminal. Furthermore, four proline residues in Pu14a adopted the trans conformation that may correlate with the large loop configuration and the biological activity of this conopeptide. The distinct structural characteristics of Pu14a will be very useful for studying the structure-activity relationship of α-conotoxins.
Collapse
Affiliation(s)
- Bingbing Zhang
- Department of Chemistry, Renmin University of China, Beijing, 100872, China
| | | | | |
Collapse
|
17
|
Ye M, Hong J, Zhou M, Huang L, Shao X, Yang Y, Sigworth FJ, Chi C, Lin D, Wang C. A novel conotoxin, qc16a, with a unique cysteine framework and folding. Peptides 2011; 32:1159-65. [PMID: 21524672 PMCID: PMC3547678 DOI: 10.1016/j.peptides.2011.04.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Revised: 04/08/2011] [Accepted: 04/09/2011] [Indexed: 10/18/2022]
Abstract
A novel conotoxin, qc16a, was identified from the venom of vermivorous Conus quercinus. qc16a has only 11 amino acid residues, DCQPCGHNVCC, with a unique cysteine pattern. Its disulfide connectivity was determined to be I-IV, II-III. The NMR structure shows that qc16a adopts a ribbon conformation with a simple beta-turn motif formed by residues Gly6, His7 and Asn8. qc16a causes depression symptom in mice when injected intracranially. Point mutation results showed that Asp1, His7 and Asn8 are all essential for the activity of qc16a. Electrophysiologically, qc16a has no strong effect on the whole-cell currents of neurons and the currents of Drosophila Shaker channels, human BK channels and Na(V)1.7 channels. Its specific target still remains to be identified.
Collapse
Affiliation(s)
- Mingyu Ye
- Institute of Protein Research, Tongji University, 1239 Siping Road, Shanghai 200092, China
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Jing Hong
- College of Biological Science and Technology, Fuzhou University, Fuzhou 350108, China
| | - Mi Zhou
- Institute of Protein Research, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Lijun Huang
- Institute of Protein Research, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Xiaoxia Shao
- Institute of Protein Research, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Youshan Yang
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Fred J. Sigworth
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Chengwu Chi
- Institute of Protein Research, Tongji University, 1239 Siping Road, Shanghai 200092, China
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Donghai Lin
- The Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
- To whom correspondence should be addressed: Chunguang Wang, Institute of Protein Research, Tongji University, 1239 Siping Road, Shanghai 200092, China, Tel: 86-21-65984347, Fax: 86-21-65988403; ; or Donghai Lin, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China, Tel: 86-592-2186078, Fax: 86-592-2186078;
| | - Chunguang Wang
- Institute of Protein Research, Tongji University, 1239 Siping Road, Shanghai 200092, China
- To whom correspondence should be addressed: Chunguang Wang, Institute of Protein Research, Tongji University, 1239 Siping Road, Shanghai 200092, China, Tel: 86-21-65984347, Fax: 86-21-65988403; ; or Donghai Lin, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China, Tel: 86-592-2186078, Fax: 86-592-2186078;
| |
Collapse
|