1
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Monroe LK, Truong DP, Miner JC, Adikari SH, Sasiene ZJ, Fenimore PW, Alexandrov B, Williams RF, Nguyen HB. Conotoxin Prediction: New Features to Increase Prediction Accuracy. Toxins (Basel) 2023; 15:641. [PMID: 37999504 PMCID: PMC10675404 DOI: 10.3390/toxins15110641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 10/27/2023] [Accepted: 10/30/2023] [Indexed: 11/25/2023] Open
Abstract
Conotoxins are toxic, disulfide-bond-rich peptides from cone snail venom that target a wide range of receptors and ion channels with multiple pathophysiological effects. Conotoxins have extraordinary potential for medical therapeutics that include cancer, microbial infections, epilepsy, autoimmune diseases, neurological conditions, and cardiovascular disorders. Despite the potential for these compounds in novel therapeutic treatment development, the process of identifying and characterizing the toxicities of conotoxins is difficult, costly, and time-consuming. This challenge requires a series of diverse, complex, and labor-intensive biological, toxicological, and analytical techniques for effective characterization. While recent attempts, using machine learning based solely on primary amino acid sequences to predict biological toxins (e.g., conotoxins and animal venoms), have improved toxin identification, these methods are limited due to peptide conformational flexibility and the high frequency of cysteines present in toxin sequences. This results in an enumerable set of disulfide-bridged foldamers with different conformations of the same primary amino acid sequence that affect function and toxicity levels. Consequently, a given peptide may be toxic when its cysteine residues form a particular disulfide-bond pattern, while alternative bonding patterns (isoforms) or its reduced form (free cysteines with no disulfide bridges) may have little or no toxicological effects. Similarly, the same disulfide-bond pattern may be possible for other peptide sequences and result in different conformations that all exhibit varying toxicities to the same receptor or to different receptors. We present here new features, when combined with primary sequence features to train machine learning algorithms to predict conotoxins, that significantly increase prediction accuracy.
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Affiliation(s)
- Lyman K. Monroe
- Bioscience Division, MS M888, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Duc P. Truong
- Theoretical Division, MS M888, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Jacob C. Miner
- Bioscience Division, MS M888, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Samantha H. Adikari
- Bioscience Division, MS M888, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Zachary J. Sasiene
- Bioscience Division, MS M888, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Paul W. Fenimore
- Theoretical Division, MS M888, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Boian Alexandrov
- Theoretical Division, MS M888, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Robert F. Williams
- Bioscience Division, MS M888, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Hau B. Nguyen
- Bioscience Division, MS M888, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
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2
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Liu Y, Zhao Z, Song Y, Yin Y, Wu F, Jiang H. Usage of Cell-Free Protein Synthesis in Post-Translational Modification of μ-Conopeptide PIIIA. Mar Drugs 2023; 21:421. [PMID: 37623702 PMCID: PMC10455749 DOI: 10.3390/md21080421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 07/20/2023] [Accepted: 07/20/2023] [Indexed: 08/26/2023] Open
Abstract
The post-translational modifications of conopeptides are the most complicated modifications to date and are well-known and closely related to the activity of conopeptides. The hydroxylation of proline in conopeptides affects folding, structure, and biological activity, and prolyl 4 hydroxylase has been characterized in Conus literatus. However, the hydroxylation machinery of proline in conopeptides is still unclear. In order to address the hydroxylation mechanism of proline in μ-PIIIA, three recombinant plasmids encoding different hybrid precursors of μ-PIIIA were constructed and crossly combined with protein disulfide isomerase, prolyl 4 hydroxylase, and glutaminyl cyclase in a continuous exchange cell-free protein system. The findings showed that prolyl 4 hydroxylase might recognize the propeptide of μ-PIIIA to achieve the hydroxylation of proline, while the cyclization of glutamate was also formed. Additionally, in Escherichia coli, the co-expression plasmid encoding prolyl 4 hydroxylase and the precursor of μ-PIIIA containing pro and mature regions were used to validate the continuous exchange cell-free protein system. Surprisingly, in addition to the two hydroxyproline residues and one pyroglutamyl residue, three disulfide bridges were formed using Trx as a fusion tag, and the yield of the fusion peptide was approximately 20 mg/L. The results of electrophysiology analysis indicated that the recombinant μ-PIIIA without C-terminal amidate inhibited the current of hNaV1.4 with a 939 nM IC50. Our work solved the issue that it was challenging to quickly generate post-translationally modified conopeptides in vitro. This is the first study to demonstrate that prolyl 4 hydroxylase catalyzes the proline hydroxylation through recognition in the propeptide of μ-PIIIA, and it will provide a new way for synthesizing multi-modified conopeptides with pharmacological activity.
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Affiliation(s)
| | | | | | | | | | - Hui Jiang
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China
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3
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Espiritu MJ, Taylor JK, Sugai CK, Thapa P, Loening NM, Gusman E, Baoanan ZG, Baumann MH, Bingham JP. Characterization of the Native Disulfide Isomers of the Novel χ-Conotoxin PnID: Implications for Further Increasing Conotoxin Diversity. Mar Drugs 2023; 21:61. [PMID: 36827103 PMCID: PMC9964023 DOI: 10.3390/md21020061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 01/11/2023] [Accepted: 01/17/2023] [Indexed: 01/21/2023] Open
Abstract
χ-Conotoxins are known for their ability to selectively inhibit norepinephrine transporters, an ability that makes them potential leads for treating various neurological disorders, including neuropathic pain. PnID, a peptide isolated from the venom of Conus pennaceus, shares high sequence homology with previously characterized χ-conotoxins. Whereas previously reported χ-conotoxins seem to only have a single native disulfide bonding pattern, PnID has three native isomers due to the formation of different disulfide bond patterns during its maturation in the venom duct. In this study, the disulfide connectivity and three-dimensional structure of these disulfide isomers were explored using regioselective synthesis, chromatographic coelution, and solution-state nuclear magnetic resonance spectroscopy. Of the native isomers, only the isomer with a ribbon disulfide configuration showed pharmacological activity similar to other χ-conotoxins. This isomer inhibited the rat norepinephrine transporter (IC50 = 10 ± 2 µM) and has the most structural similarity to previously characterized χ-conotoxins. In contrast, the globular isoform of PnID showed more than ten times less activity against this transporter and the beaded isoform did not display any measurable biological activity. This study is the first report of the pharmacological and structural characterization of an χ-conotoxin from a species other than Conus marmoreus and is the first report of the existence of natively-formed conotoxin isomers.
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Affiliation(s)
- Michael J. Espiritu
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai’i, Honolulu, HI 96822, USA
- School of Pharmacy, Pacific University, 222 SE 8th Ave, Ste. 451, Hillsboro, OR 97123, USA
| | - Jonathan K. Taylor
- School of Pharmacy, Pacific University, 222 SE 8th Ave, Ste. 451, Hillsboro, OR 97123, USA
| | - Christopher K. Sugai
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai’i, Honolulu, HI 96822, USA
| | - Parashar Thapa
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai’i, Honolulu, HI 96822, USA
| | - Nikolaus M. Loening
- Department of Chemistry, Lewis & Clark College, 615 S Palatine Hill Road, Portland, OR 97219, USA
| | - Emma Gusman
- School of Pharmacy, Pacific University, 222 SE 8th Ave, Ste. 451, Hillsboro, OR 97123, USA
| | - Zenaida G. Baoanan
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai’i, Honolulu, HI 96822, USA
- Department of Biology, College of Science, University of the Philippines Baguio, Baguio City 2600, Philippines
| | - Michael H. Baumann
- Designer Drug Research Unit, Intramural Research Program, National Institute on Drug Abuse (NIDA), National Institutes of Health (NIH), 333 Cassell Drive Suite 4400, Baltimore, MD 21224, USA
| | - Jon-Paul Bingham
- Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawai’i, Honolulu, HI 96822, USA
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4
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A Single Amino Acid Replacement Boosts the Analgesic Activity of α-Conotoxin AuIB through the Inhibition of the GABA BR-Coupled N-Type Calcium Channel. Mar Drugs 2022; 20:md20120750. [PMID: 36547897 PMCID: PMC9781320 DOI: 10.3390/md20120750] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/17/2022] [Accepted: 11/22/2022] [Indexed: 11/30/2022] Open
Abstract
α-conotoxin AuIB is the only one of the 4/6 type α-conotoxins (α-CTxs) that inhibits the γ-aminobutyric acid receptor B (GABABR)-coupled N-type calcium channel (CaV2.2). To improve its inhibitory activity, a series of variants were synthesized and evaluated according to the structure-activity relationships of 4/7 type α-CTxs targeting GABABR-coupled CaV2.2. Surprisingly, only the substitution of Pro7 with Arg results in a 2-3-fold increase in the inhibition of GABABR-coupled CaV2.2 (IC50 is 0.74 nM); substitutions of position 9-12 with basic or hydrophobic amino acid and the addition of hydrophobic amino acid Leu or Ile at the second loop to mimic 4/7 type α-CTxs all failed to improve the inhibitory activity of AuIB against GABABR-coupled CaV2.2. Interestingly, the most potent form of AuIB[P7R] has disulfide bridges of "1-4, 2-3" (ribbon), which differs from the "1-3, 2-4" (globular) in the isoforms of wildtype AuIB. In addition, AuIB[P7R](globular) displays potent analgesic activity in the acetic acid writhing model and the partial sciatic nerve injury (PNL) model. Our study demonstrated that 4/6 type α-CTxs, with the disulfide bridge connectivity "1-4, 2-3," are also potent inhibitors for GABABR-coupled CaV2.2, exhibiting potent analgesic activity.
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5
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Single-Disulfide Conopeptide Czon1107, an Allosteric Antagonist of the Human α3β4 Nicotinic Acetylcholine Receptor. Mar Drugs 2022; 20:md20080497. [PMID: 36005500 PMCID: PMC9409646 DOI: 10.3390/md20080497] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 07/27/2022] [Accepted: 07/29/2022] [Indexed: 11/16/2022] Open
Abstract
Conopeptides are peptides in the venom of marine cone snails that are used for capturing prey or as a defense against predators. A new cysteine-poor conopeptide, Czon1107, has exhibited non-competitive inhibition with an undefined allosteric mechanism in the human (h) α3β4 nicotinic acetylcholine receptors (nAChRs). In this study, the binding mode of Czon1107 to hα3β4 nAChR was investigated using molecular dynamics simulations coupled with mutagenesis studies of the peptide and electrophysiology studies on heterologous hα3β4 nAChRs. Overall, this study clarifies the structure–activity relationship of Czon1107 and hα3β4 nAChR and provides an important experimental and theoretical basis for the development of new peptide drugs.
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6
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Tran HNT, McMahon KL, Deuis JR, Vetter I, Schroeder CI. Structural and functional insights into the inhibition of human voltage-gated sodium channels by μ-conotoxin KIIIA disulfide isomers. J Biol Chem 2022; 298:101728. [PMID: 35167877 PMCID: PMC8927997 DOI: 10.1016/j.jbc.2022.101728] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 02/08/2022] [Accepted: 02/11/2022] [Indexed: 12/13/2022] Open
Abstract
μ-Conotoxins are components of cone snail venom, well-known for their analgesic activity through potent inhibition of voltage-gated sodium channel (NaV) subtypes, including NaV1.7. These small, disulfide-rich peptides are typically stabilized by three disulfide bonds arranged in a ‘native’ CysI-CysIV, CysII-CysV, CysIII-CysVI pattern of disulfide connectivity. However, μ-conotoxin KIIIA, the smallest and most studied μ-conotoxin with inhibitory activity at NaV1.7, forms two distinct disulfide bond isomers during thermodynamic oxidative folding, including Isomer 1 (CysI-CysV, CysII-CysIV, CysIII-CysVI) and Isomer 2 (CysI-CysVI, CysII-CysIV, CysIII-CysV), but not the native μ-conotoxin arrangement. To date, there has been no study on the structure and activity of KIIIA comprising the native μ-conotoxin disulfide bond arrangement. Here, we evaluated the synthesis, potency, sodium channel subtype selectivity, and 3D structure of the three isomers of KIIIA. Using a regioselective disulfide bond-forming strategy, we synthetically produced the three μ-conotoxin KIIIA isomers displaying distinct bioactivity and NaV subtype selectivity across human NaV channel subtypes 1.2, 1.4, and 1.7. We show that Isomer 1 inhibits NaV subtypes with a rank order of potency of NaV1.4 > 1.2 > 1.7 and Isomer 2 in the order of NaV1.4≈1.2 > 1.7, while the native isomer inhibited NaV1.4 > 1.7≈1.2. The three KIIIA isomers were further evaluated by NMR solution structure analysis and molecular docking with hNaV1.2. Our study highlights the importance of investigating alternate disulfide isomers, as disulfide connectivity affects not only the overall structure of the peptides but also the potency and subtype selectivity of μ-conotoxins targeting therapeutically relevant NaV subtypes.
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Affiliation(s)
- Hue N T Tran
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
| | - Kirsten L McMahon
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
| | - Jennifer R Deuis
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
| | - Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia; School of Pharmacy, The University of Queensland, Woolloongabba, Queensland, Australia.
| | - Christina I Schroeder
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia; Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland, USA.
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7
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Wang X, Liao Q, Chen H, Gong G, Siu SWI, Chen Q, Kam H, Ung COL, Cheung KK, Rádis-Baptista G, Wong CTT, Lee SMY. Toxic Peptide From Palythoa caribaeorum Acting on the TRPV1 Channel Prevents Pentylenetetrazol-Induced Epilepsy in Zebrafish Larvae. Front Pharmacol 2021; 12:763089. [PMID: 34925021 PMCID: PMC8672801 DOI: 10.3389/fphar.2021.763089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 11/08/2021] [Indexed: 11/25/2022] Open
Abstract
PcActx peptide, identified from the transcriptome of zoantharian Palythoa caribaeorum, was clustered into the phylogeny of analgesic polypeptides from sea anemone Heteractis crispa (known as APHC peptides). APHC peptides were considered as inhibitors of transient receptor potential cation channel subfamily V member 1 (TRPV1). TRPV1 is a calcium-permeable channel expressed in epileptic brain areas, serving as a potential target for preventing epileptic seizures. Through in silico and in vitro analysis, PcActx peptide was shown to be a potential TRPV1 channel blocker. In vivo studies showed that the linear and oxidized PcActx peptides caused concentration-dependent increases in mortality of zebrafish larvae. However, monotreatment with PcActx peptides below the maximum tolerated doses (MTD) did not affect locomotor behavior. Moreover, PcActx peptides (both linear and oxidized forms) could effectively reverse pentylenetetrazol (PTZ)-induced seizure-related behavior in zebrafish larvae and prevent overexpression of c-fos and npas4a at the mRNA level. The excessive production of ROS induced by PTZ was markedly attenuated by both linear and oxidized PcActx peptides. It was also verified that the oxidized PcActx peptide was more effective than the linear one. In particular, oxidized PcActx peptide notably modulated the mRNA expression of genes involved in calcium signaling and γ-aminobutyric acid (GABA)ergic-glutamatergic signaling, including calb1, calb2, gabra1, grm1, gria1b, grin2b, gat1, slc1a2b, gad1b, and glsa. Taken together, PcActx peptide, as a novel neuroactive peptide, exhibits prominent anti-epileptic activity, probably through modulating calcium signaling and GABAergic-glutamatergic signaling, and is a promising candidate for epilepsy management.
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Affiliation(s)
- Xiufen Wang
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Qiwen Liao
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macau, China.,School of Life and Health Sciences, The Chinese University of Hong Kong, Shenzhen, China
| | - Hanbin Chen
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Guiyi Gong
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Shirley Weng In Siu
- Department of Computer and Information Science, Faculty of Science and Technology, University of Macau, Macau, China
| | - Qian Chen
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Hiotong Kam
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Carolina Oi Lam Ung
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Kwok-Kuen Cheung
- Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, China
| | - Gandhi Rádis-Baptista
- Laboratory of Biochemistry and Biotechnology, Institute for Marine Sciences, Federal University of Ceará, Fortaleza, Brazil
| | - Clarence Tsun Ting Wong
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong, China
| | - Simon Ming-Yuen Lee
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macau, China
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8
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Ho TNT, Abraham N, Lewis RJ. Rigidity of loop 1 contributes to equipotency of globular and ribbon isomers of α-conotoxin AusIA. Sci Rep 2021; 11:21928. [PMID: 34753970 PMCID: PMC8578332 DOI: 10.1038/s41598-021-01277-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 10/19/2021] [Indexed: 11/09/2022] Open
Abstract
α-Conotoxins are small disulfide-rich peptides targeting nicotinic acetylcholine receptors (nAChRs) characterised by a CICII-Xm-CIII-Xn-CIV framework that invariably adopt the native globular conformations which is typically most potent. α-Conotoxins are divided into several structural subgroups based on the number of residues within the two loops braced by the disulfide bonds (m/n), with the 4/7 and 4/3 subgroups dominating. AusIA is a relatively rare α5/5-conotoxin isolated from the venom of Conus australis. Surprisingly, the ribbon isomer displayed equipotency to the wild-type globular AusIA at human α7-containing nAChR. To understand the molecular basis for equipotency, we determined the co-crystal structures of both isomers at Lymnea stagnalis acetylcholine binding protein. The additional residue in the first loop of AusIA was found to be a critical determinant of equipotency, with 11-fold and 86-fold shifts in potency in favour of globular AusIA over ribbon AusIA observed following deletion of Ala4 or Arg5, respectively. This divergence in the potency between globular AusIA and ribbon AusIA was further enhanced upon truncation of the non-conserved Val at the C-termini. Conversely, equipotency could be replicated in LsIA and TxIA [A10L] following insertion of an Ala in the first loop. These findings provide a new understanding of the role the first loop in ribbon and globular α-conotoxins can play in directing α-conotoxin nAChR pharmacology.
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Affiliation(s)
- Thao N T Ho
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, 4067, Australia
| | - Nikita Abraham
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, 4067, Australia
| | - Richard J Lewis
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, 4067, Australia.
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9
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Sanches K, Wai DCC, Norton RS. Conformational dynamics in peptide toxins: Implications for receptor interactions and molecular design. Toxicon 2021; 201:127-140. [PMID: 34454969 DOI: 10.1016/j.toxicon.2021.08.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 08/19/2021] [Accepted: 08/23/2021] [Indexed: 10/20/2022]
Abstract
Peptide toxins are potent and often exquisitely selective probes of the structure and function of ion channels and receptors, and are therefore of significant interest to the pharmaceutical and biotech industries as both pharmacological tools and therapeutic leads. The three-dimensional structures of peptide toxins are essential as a basis for understanding their structure-activity relationships and their binding to target receptors, as well as in guiding the design of analogues with modified potency and/or selectivity for key targets. NMR spectroscopy has played a key role in elucidating the structures of peptide toxins and probing their structure-function relationships. In this article, we highlight the additional important contribution of NMR to characterising the dynamics of peptide toxins. We also compare the information available from NMR measurements with that afforded by molecular dynamics simulations. We describe several examples of the importance of dynamics measurements over a range of timescales for understanding the structure-function relationships of peptide toxins and their receptor engagement. Peptide toxins that inhibit the voltage-gated potassium channel KV1.3 with pM affinities display different degrees of conformational flexibility, even though they contain multiple disulfide bonds, and this flexibility can affect the relative orientation of residues that have been shown to be critical for channel binding. Information on the dynamic properties of peptide toxins is important in the design of analogues or mimetics where receptor-bound structures are not available.
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Affiliation(s)
- Karoline Sanches
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia; ARC Centre for Fragment-Based Design, Monash University, Parkville, Victoria, 3052, Australia
| | - Dorothy C C Wai
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia
| | - Raymond S Norton
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia; ARC Centre for Fragment-Based Design, Monash University, Parkville, Victoria, 3052, Australia.
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10
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Tae HS, Gao B, Jin AH, Alewood PF, Adams DJ. Globular and ribbon isomers of Conus geographus α-conotoxins antagonize human nicotinic acetylcholine receptors. Biochem Pharmacol 2021; 190:114638. [PMID: 34062129 DOI: 10.1016/j.bcp.2021.114638] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 05/27/2021] [Accepted: 05/27/2021] [Indexed: 11/29/2022]
Abstract
The short disulfide-rich α-conotoxins derived from the venom of Conus snails comprise a conserved CICII(m)CIII(n)CIV cysteine framework (m and n, number of amino acids) and the majority antagonize nicotinic acetylcholine receptors (nAChRs). Depending on disulfide connectivity, α-conotoxins can exist as either globular (CI-CIII, CII-CIV), ribbon (CI-CIV, CII-CIII) or bead (CI-CII, CIII-CIV) isomers. In the present study, C. geographus α-conotoxins GI, GIB, G1.5 and G1.9 were chemically synthesized as globular and ribbon isomers and their activity investigated at human nAChRs expressed in Xenopus oocytes using the two-electrode voltage clamp recording technique. Both the globular and ribbon isomers of the 3/5 (m/n) α-conotoxins GI and GIB selectively inhibit heterologous human muscle-type α1β1δε nAChRs, whereas G1.5, a 4/7 α-conotoxin, selectively antagonizes neuronal (non-muscle) nAChR subtypes particularly human α3β2, α7 and α9α10 nAChRs. In contrast, globular and ribbon isomers of G1.9, a novel C-terminal elongated 4/8 α-conotoxin exhibited no activity at the human nAChR subtypes studied. This study reinforces earlier observations that 3/5 α-conotoxins selectively target the muscle nAChR subtypes, although interestingly, GIB is also active at α7 and α9 α10 nAChRs. The 4/7 α-conotoxins target human neuronal nAChR subtypes whereas the pharmacology of the 4/8 α-conotoxin remains unknown.
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Affiliation(s)
- Han-Shen Tae
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, NSW 2522, Australia.
| | - Bingmiao Gao
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Key Laboratory for Research and Development of Tropical Herbs, Hainan Medical University, Haikou 571199, China
| | - Ai-Hua Jin
- Institute for Molecular Bioscience, University of Queensland, St Lucia, QLD 4072, Australia
| | - Paul F Alewood
- Institute for Molecular Bioscience, University of Queensland, St Lucia, QLD 4072, Australia
| | - David J Adams
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, NSW 2522, Australia.
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11
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Wang CK, Craik DJ. Linking molecular evolution to molecular grafting. J Biol Chem 2021; 296:100425. [PMID: 33600801 PMCID: PMC8005815 DOI: 10.1016/j.jbc.2021.100425] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 02/09/2021] [Accepted: 02/13/2021] [Indexed: 12/01/2022] Open
Abstract
Molecular grafting is a strategy for the engineering of molecular scaffolds into new functional agents, such as next-generation therapeutics. Despite its wide use, studies so far have focused almost exclusively on demonstrating its utility rather than understanding the factors that lead to either poor or successful grafting outcomes. Here, we examine protein evolution and identify parallels between the natural process of protein functional diversification and the artificial process of molecular grafting. We discuss features of natural proteins that are correlated to innovability-the capacity to acquire new functions-and describe their implications to molecular grafting scaffolds. Disulfide-rich peptides are used as exemplars because they are particularly promising scaffolds onto which new functions can be grafted. This article provides a perspective on why some scaffolds are more suitable for grafting than others, identifying opportunities on how molecular grafting might be improved.
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Affiliation(s)
- Conan K Wang
- Institute for Molecular Bioscience and Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland, Australia.
| | - David J Craik
- Institute for Molecular Bioscience and Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland, Australia
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12
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Schmitz T, Pengelley S, Belau E, Suckau D, Imhof D. LC-Trapped Ion Mobility Spectrometry-TOF MS Differentiation of 2- and 3-Disulfide-Bonded Isomers of the μ-Conotoxin PIIIA. Anal Chem 2020; 92:10920-10924. [PMID: 32806900 DOI: 10.1021/acs.analchem.0c02151] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Disulfide bonds within cysteine-rich peptides are important for their stability and biological function. In this respect, the correct disulfide connectivity plays a decisive role. The differentiation of individual disulfide-bonded isomers by traditional high-performance liquid chromatography (HPLC) and mass spectrometry (MS) is limited due to the similarity in physicochemical properties of the isomers sharing the same amino acid sequence. By using trapped ion mobility spectrometry-mass spectrometry (TIMS-MS), several 2- and 3-disulfide-bonded isomers of the μ-conotoxin PIIIA were investigated for their distinguishability by collision cross section (CCS) values and their characteristic mobilogram traces. The isomers could be differentiated by TIMS-MS and also identified in mixing experiments. Thus, TIMS-MS provides a highly valuable and enriching addition to standard HPLC and MS analysis of conformational isomers of disulfide-rich peptides and proteins.
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Affiliation(s)
- Thomas Schmitz
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, 53121 Bonn, Germany
| | - Stuart Pengelley
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, 53121 Bonn, Germany
| | - Eckhard Belau
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, 53121 Bonn, Germany
| | - Detlev Suckau
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, 53121 Bonn, Germany
| | - Diana Imhof
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, 53121 Bonn, Germany
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13
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Sajeevan KA, Roy D. Simulation of differential structure and dynamics of disulfide bond isoforms of conopeptide
AuIB
in presence of human
α
3
β
4
nAChR. Pept Sci (Hoboken) 2020. [DOI: 10.1002/pep2.24183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Karuna Anna Sajeevan
- Department of Chemistry Birla Institute of Technology and Science‐Pilani Hyderabad Telangana India
| | - Durba Roy
- Department of Chemistry Birla Institute of Technology and Science‐Pilani Hyderabad Telangana India
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14
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Kennedy AC, Belgi A, Husselbee BW, Spanswick D, Norton RS, Robinson AJ. α-Conotoxin Peptidomimetics: Probing the Minimal Binding Motif for Effective Analgesia. Toxins (Basel) 2020; 12:E505. [PMID: 32781580 PMCID: PMC7472027 DOI: 10.3390/toxins12080505] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 07/29/2020] [Accepted: 08/03/2020] [Indexed: 12/18/2022] Open
Abstract
Several analgesic α-conotoxins have been isolated from marine cone snails. Structural modification of native peptides has provided potent and selective analogues for two of its known biological targets-nicotinic acetylcholine and γ-aminobutyric acid (GABA) G protein-coupled (GABAB) receptors. Both of these molecular targets are implicated in pain pathways. Despite their small size, an incomplete understanding of the structure-activity relationship of α-conotoxins at each of these targets has hampered the development of therapeutic leads. This review scrutinises the N-terminal domain of the α-conotoxin family of peptides, a region defined by an invariant disulfide bridge, a turn-inducing proline residue and multiple polar sidechain residues, and focusses on structural features that provide analgesia through inhibition of high-voltage-activated Ca2+ channels. Elucidating the bioactive conformation of this region of these peptides may hold the key to discovering potent drugs for the unmet management of debilitating chronic pain associated with a wide range of medical conditions.
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Affiliation(s)
- Adam C. Kennedy
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia; (A.C.K.); (A.B.); (B.W.H.)
| | - Alessia Belgi
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia; (A.C.K.); (A.B.); (B.W.H.)
| | - Benjamin W. Husselbee
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia; (A.C.K.); (A.B.); (B.W.H.)
| | - David Spanswick
- Biomedicine Discovery Institute and the Department of Physiology, Monash University, Victoria 3800, Australia;
- Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
- NeuroSolutions Ltd., Coventry CV4 7AL, UK
| | - Raymond S. Norton
- Medicinal Chemistry, Monash Institute of Pharmaceutical Science, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia;
- ARC Centre for Fragment-Based Design, Monash University, Parkville, Victoria 3052, Australia
| | - Andrea J. Robinson
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia; (A.C.K.); (A.B.); (B.W.H.)
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15
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Mansbach RA, Chakraborty S, Travers T, Gnanakaran S. Graph-Directed Approach for Downselecting Toxins for Experimental Structure Determination. Mar Drugs 2020; 18:E256. [PMID: 32422972 PMCID: PMC7281422 DOI: 10.3390/md18050256] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 04/24/2020] [Accepted: 05/09/2020] [Indexed: 11/29/2022] Open
Abstract
Conotoxins are short, cysteine-rich peptides of great interest as novel therapeutic leads and of great concern as lethal biological agents due to their high affinity and specificity for various receptors involved in neuromuscular transmission. Currently, of the approximately 6000 known conotoxin sequences, only about 3% have associated structural characterization, which leads to a bottleneck in rapid high-throughput screening (HTS) for identification of potential leads or threats. In this work, we combine a graph-based approach with homology modeling to expand the library of conotoxin structures and to identify those conotoxin sequences that are of the greatest value for experimental structural characterization. The latter would allow for the rapid expansion of the known structural space for generating high quality template-based models. Our approach generalizes to other evolutionarily-related, short, cysteine-rich venoms of interest. Overall, we present and validate an approach for venom structure modeling and experimental guidance and employ it to produce a 290%-larger library of approximate conotoxin structures for HTS. We also provide a set of ranked conotoxin sequences for experimental structure determination to further expand this library.
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Affiliation(s)
- Rachael A. Mansbach
- Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos, NM 87545, USA; (R.A.M.); (S.C.); (T.T.)
| | - Srirupa Chakraborty
- Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos, NM 87545, USA; (R.A.M.); (S.C.); (T.T.)
- Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Timothy Travers
- Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos, NM 87545, USA; (R.A.M.); (S.C.); (T.T.)
- Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - S. Gnanakaran
- Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos, NM 87545, USA; (R.A.M.); (S.C.); (T.T.)
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16
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Kan MW, Craik DJ. Discovery of Cyclotides from Australasian Plants. Aust J Chem 2020. [DOI: 10.1071/ch19658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This article is part of a special issue celebrating the contributions of Professor Paul Alewood to peptide science. We begin by providing a summary of collaborative projects between the Alewood and Craik groups at The University of Queensland and highlighting the impacts of some of these studies. In particular, studies on the discovery, synthesis, structures, and bioactivities of disulfide-rich toxins from animal venoms have led to a greater understanding of the biology of ion channels and to applications of these bioactive peptides in drug design. The second part of the article focuses on plant-derived disulfide-rich cyclic peptides, known as cyclotides, and includes an analysis of the geographical distribution of Australasian plant species that contain cyclotides as well as an analysis of the diversity of cyclotide sequences found in Australasian plants. This should provide a useful resource for researchers to access native cyclotides and explore their chemistry and biology.
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17
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Marquart LA, Turner MW, Warner LR, King MD, Groome JR, McDougal OM. Ribbon α-Conotoxin KTM Exhibits Potent Inhibition of Nicotinic Acetylcholine Receptors. Mar Drugs 2019; 17:E669. [PMID: 31795126 PMCID: PMC6950571 DOI: 10.3390/md17120669] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 11/21/2019] [Accepted: 11/21/2019] [Indexed: 01/26/2023] Open
Abstract
KTM is a 16 amino acid peptide with the sequence WCCSYPGCYWSSSKWC. Here, we present the nuclear magnetic resonance (NMR) structure and bioactivity of this rationally designed α-conotoxin (α-CTx) that demonstrates potent inhibition of rat α3β2-nicotinic acetylcholine receptors (rα3β2-nAChRs). Two bioassays were used to test the efficacy of KTM. First, a qualitative PC12 cell-based assay confirmed that KTM acts as a nAChR antagonist. Second, bioactivity evaluation by two-electrode voltage clamp electrophysiology was used to measure the inhibition of rα3β2-nAChRs by KTM (IC50 = 0.19 ± 0.02 nM), and inhibition of the same nAChR isoform by α-CTx MII (IC50 = 0.35 ± 0.8 nM). The three-dimensional structure of KTM was determined by NMR spectroscopy, and the final set of 20 structures derived from 32 distance restraints, four dihedral angle constraints, and two disulfide bond constraints overlapped with a mean global backbone root-mean-square deviation (RMSD) of 1.7 ± 0.5 Å. The structure of KTM did not adopt the disulfide fold of α-CTx MII for which it was designed, but instead adopted a flexible ribbon backbone and disulfide connectivity of C2-C16 and C3-C8 with an estimated 12.5% α-helical content. In contrast, α-CTx MII, which has a native fold of C2-C8 and C3-C16, has an estimated 38.1% α-helical secondary structure. KTM is the first reported instance of a Framework I (CC-C-C) α-CTx with ribbon connectivity to display sub-nanomolar inhibitory potency of rα3β2-nAChR subtypes.
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Affiliation(s)
- Leanna A. Marquart
- Department of Chemistry and Biochemistry, Boise State University, Boise, ID 83725, USA; (L.A.M.); (L.R.W.); (M.D.K.)
| | - Matthew W. Turner
- Biomolecular Sciences PhD Program, Boise State University, Boise, ID 83725, USA;
| | - Lisa R. Warner
- Department of Chemistry and Biochemistry, Boise State University, Boise, ID 83725, USA; (L.A.M.); (L.R.W.); (M.D.K.)
| | - Matthew D. King
- Department of Chemistry and Biochemistry, Boise State University, Boise, ID 83725, USA; (L.A.M.); (L.R.W.); (M.D.K.)
| | - James R. Groome
- Department of Biological Sciences, Idaho State University, Pocatello, ID 83209, USA;
| | - Owen M. McDougal
- Department of Chemistry and Biochemistry, Boise State University, Boise, ID 83725, USA; (L.A.M.); (L.R.W.); (M.D.K.)
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18
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Paul George AA, Heimer P, Leipold E, Schmitz T, Kaufmann D, Tietze D, Heinemann SH, Imhof D. Effect of Conformational Diversity on the Bioactivity of µ-Conotoxin PIIIA Disulfide Isomers. Mar Drugs 2019; 17:E390. [PMID: 31269696 PMCID: PMC6669574 DOI: 10.3390/md17070390] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 06/21/2019] [Accepted: 06/25/2019] [Indexed: 12/25/2022] Open
Abstract
Cyclic µ-conotoxin PIIIA, a potent blocker of skeletal muscle voltage-gated sodium channel NaV1.4, is a 22mer peptide stabilized by three disulfide bonds. Combining electrophysiological measurements with molecular docking and dynamic simulations based on NMR solution structures, we investigated the 15 possible 3-disulfide-bonded isomers of µ-PIIIA to relate their blocking activity at NaV1.4 to their disulfide connectivity. In addition, three µ-PIIIA mutants derived from the native disulfide isomer, in which one of the disulfide bonds was omitted (C4-16, C5-C21, C11-C22), were generated using a targeted protecting group strategy and tested using the aforementioned methods. The 3-disulfide-bonded isomers had a range of different conformational stabilities, with highly unstructured, flexible conformations with low or no channel-blocking activity, while more constrained molecules preserved 30% to 50% of the native isomer's activity. This emphasizes the importance and direct link between correct fold and function. The elimination of one disulfide bond resulted in a significant loss of blocking activity at NaV1.4, highlighting the importance of the 3-disulfide-bonded architecture for µ-PIIIA. µ-PIIIA bioactivity is governed by a subtle interplay between an optimally folded structure resulting from a specific disulfide connectivity and the electrostatic potential of the conformational ensemble.
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Affiliation(s)
- Ajay Abisheck Paul George
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
| | - Pascal Heimer
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
| | - Enrico Leipold
- Department of Anesthesiology and Intensive Care, University of Lübeck, Ratzeburger Allee 160, D-23562 Lübeck, Germany
| | - Thomas Schmitz
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
| | - Desiree Kaufmann
- Eduard Zintl Institute of Inorganic and Physical Chemistry, Darmstadt University of Technology, Alarich-Weiss-Str. 4, D-64287 Darmstadt, Germany
| | - Daniel Tietze
- Eduard Zintl Institute of Inorganic and Physical Chemistry, Darmstadt University of Technology, Alarich-Weiss-Str. 4, D-64287 Darmstadt, Germany
| | - Stefan H Heinemann
- Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena and Jena University Hospital, Hans-Knöll-Str. 2, D-07745 Jena, Germany
| | - Diana Imhof
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany.
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19
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van Hout M, Valdes A, Christensen SB, Tran PT, Watkins M, Gajewiak J, Jensen AA, Olivera BM, McIntosh JM. α-Conotoxin VnIB from Conus ventricosus is a potent and selective antagonist of α6β4* nicotinic acetylcholine receptors. Neuropharmacology 2019; 157:107691. [PMID: 31255696 DOI: 10.1016/j.neuropharm.2019.107691] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 06/05/2019] [Accepted: 06/26/2019] [Indexed: 01/20/2023]
Abstract
α6-containing (α6*) nicotinic acetylcholine receptors (nAChRs) are expressed throughout the periphery and the central nervous system and constitute putative therapeutic targets in pain, addiction and movement disorders. The α6β2* nAChRs are relatively well studied, in part due to the availability of target specific α-conotoxins (α-Ctxs). In contrast, all native α-Ctxs identified that potently block α6β4 nAChRs exhibit higher potencies for the closely related α6β2β3 and/or α3β4 subtypes. In this study, we have identified a novel peptide from Conus ventricosus with pronounced selectivity for the α6β4 nAChR. The peptide-encoding gene was cloned from genomic DNA and the predicted mature peptide, α-Ctx VnIB, was synthesized. The functional properties of VnIB were characterized at rat and human nAChRs expressed in Xenopus oocytes by two-electrode voltage clamp electrophysiology. VnIB potently inhibited ACh-evoked currents at rα6β4 and rα6/α3β4 nAChRs, displayed ∼20-fold and ∼250-fold lower potencies at rα3β4 and rα6/α3β2β3 receptors, respectively, and exhibited negligible effects at eight other nAChR subtypes. Interestingly, even higher degrees of selectivity were observed for hα6/α3β4 over hα6/α3β2β3 and hα3β4 receptors. Finally, VnIB displayed fast binding kinetics at rα6/α3β4 (on-rate t½ = 0.87 min-1, off-rate t½ = 2.7 min-1). The overall preference of VnIB for β4* over β2* nAChRs is similar to the selectivity profiles of other 4/6 α-Ctxs. However, in contrast to previously identified native α-Ctxs targeting α6* nAChRs, VnIB displays pronounced selectivity for α6β4 nAChRs over both α3β4 and α6β2β3 receptors. VnIB thus represents a novel molecular probe for elucidating the physiological role and therapeutic properties of α6β4* nAChRs.
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Affiliation(s)
- Marloes van Hout
- Department of Biology, University of Utah, Salt Lake City, UT, 84112, USA; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Amanda Valdes
- Department of Biology, University of Utah, Salt Lake City, UT, 84112, USA
| | - Sean B Christensen
- Department of Biology, University of Utah, Salt Lake City, UT, 84112, USA.
| | - Phuong T Tran
- Department of Biology, University of Utah, Salt Lake City, UT, 84112, USA
| | - Maren Watkins
- Department of Biology, University of Utah, Salt Lake City, UT, 84112, USA; Department of Pathology, University of Utah, Salt Lake City, UT, 84112, USA.
| | - Joanna Gajewiak
- Department of Biology, University of Utah, Salt Lake City, UT, 84112, USA.
| | - Anders A Jensen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | | | - J Michael McIntosh
- Department of Biology, University of Utah, Salt Lake City, UT, 84112, USA; Department of Psychiatry, University of Utah, Salt Lake City, UT, 84108, USA; George E. Wahlen Veterans Affair Medical Center, Salt Lake City, UT, 84148, USA.
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20
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El Hamdaoui Y, Wu X, Clark RJ, Giribaldi J, Anangi R, Craik DJ, King GF, Dutertre S, Kaas Q, Herzig V, Nicke A. Periplasmic Expression of 4/7 α-Conotoxin TxIA Analogs in E. coli Favors Ribbon Isomer Formation - Suggestion of a Binding Mode at the α7 nAChR. Front Pharmacol 2019; 10:577. [PMID: 31214027 PMCID: PMC6554660 DOI: 10.3389/fphar.2019.00577] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 05/06/2019] [Indexed: 01/02/2023] Open
Abstract
Peptides derived from animal venoms provide important research tools for biochemical and pharmacological characterization of receptors, ion channels, and transporters. Some venom peptides have been developed into drugs (such as the synthetic ω-conotoxin MVIIA, ziconotide) and several are currently undergoing clinical trials for various clinical indications. Challenges in the development of peptides include their usually limited supply from natural sources, cost-intensive chemical synthesis, and potentially complicated stereoselective disulfide-bond formation in the case of disulfide-rich peptides. In particular, if extended structure–function analysis is performed or incorporation of stable isotopes for NMR studies is required, the comparatively low yields and high costs of synthesized peptides might constitute a limiting factor. Here we investigated the expression of the 4/7 α-conotoxin TxIA, a potent blocker at α3β2 and α7 nicotinic acetylcholine receptors (nAChRs), and three analogs in the form of maltose binding protein fusion proteins in Escherichia coli. Upon purification via nickel affinity chromatography and release of the toxins by protease cleavage, HPLC analysis revealed one major peak with the correct mass for all peptides. The final yield was 1–2 mg of recombinant peptide per liter of bacterial culture. Two-electrode voltage clamp analysis on oocyte-expressed nAChR subtypes demonstrated the functionality of these peptides but also revealed a 30 to 100-fold potency decrease of expressed TxIA compared to chemically synthesized TxIA. NMR spectroscopy analysis of TxIA and two of its analogs confirmed that the decreased activity was due to an alternative disulfide linkage rather than the missing C-terminal amidation, a post-translational modification that is common in α-conotoxins. All peptides preferentially formed in the ribbon conformation rather than the native globular conformation. Interestingly, in the case of the α7 nAChR, but not the α3β2 subtype, the loss of potency could be rescued by an R5D substitution. In conclusion, we demonstrate efficient expression of functional but alternatively folded ribbon TxIA variants in E. coli and provide the first structure–function analysis for a ribbon 4/7-α-conotoxin at α7 and α3β2 nAChRs. Computational analysis based on these data provide evidence for a ribbon α-conotoxin binding mode that might be exploited to design ligands with optimized selectivity.
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Affiliation(s)
- Yamina El Hamdaoui
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Xiaosa Wu
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Richard J Clark
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Julien Giribaldi
- CNRS, Institut des Biomolécules Max Mousseron, UMR 5247, Université de Montpellier, Montpellier, France
| | - Raveendra Anangi
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - David J Craik
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Sebastien Dutertre
- CNRS, Institut des Biomolécules Max Mousseron, UMR 5247, Université de Montpellier, Montpellier, France
| | - Quentin Kaas
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Volker Herzig
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Annette Nicke
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
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21
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Knuhtsen A, Whitmore C, McWhinnie FS, McDougall L, Whiting R, Smith BO, Timperley CM, Green AC, Kinnear KI, Jamieson AG. α-Conotoxin GI triazole-peptidomimetics: potent and stable blockers of a human acetylcholine receptor. Chem Sci 2019. [DOI: 10.1039/c8sc04198a] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A conotoxin peptidomimetic was developed as a potential muscle relaxant that is highly potent and blood plasma stable.
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Affiliation(s)
| | - Charlotte Whitmore
- Chemical, Biological and Radiological Division
- Defence Science and Technology Laboratory
- Salisbury
- SP4 0JQ UK
| | | | | | - Rachel Whiting
- Chemical, Biological and Radiological Division
- Defence Science and Technology Laboratory
- Salisbury
- SP4 0JQ UK
| | - Brian O. Smith
- Institute of Molecular, Cell & Systems Biology
- College of Medical, Veterinary & Life Sciences
- University of Glasgow
- Glasgow
- G12 8QQ UK
| | - Christopher M. Timperley
- Chemical, Biological and Radiological Division
- Defence Science and Technology Laboratory
- Salisbury
- SP4 0JQ UK
| | - A. Christopher Green
- Chemical, Biological and Radiological Division
- Defence Science and Technology Laboratory
- Salisbury
- SP4 0JQ UK
| | - Kenneth I. Kinnear
- Chemical, Biological and Radiological Division
- Defence Science and Technology Laboratory
- Salisbury
- SP4 0JQ UK
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22
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Liao Q, Li S, Siu SWI, Morlighem JÉRL, Wong CTT, Wang X, Rádis-Baptista G, Lee SMY. Novel neurotoxic peptides from Protopalythoa variabilis virtually interact with voltage-gated sodium channel and display anti-epilepsy and neuroprotective activities in zebrafish. Arch Toxicol 2018; 93:189-206. [DOI: 10.1007/s00204-018-2334-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 10/10/2018] [Indexed: 02/06/2023]
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23
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Wu X, Tae HS, Huang YH, Adams DJ, Craik DJ, Kaas Q. Stoichiometry dependent inhibition of rat α3β4 nicotinic acetylcholine receptor by the ribbon isomer of α-conotoxin AuIB. Biochem Pharmacol 2018; 155:288-297. [PMID: 30009767 DOI: 10.1016/j.bcp.2018.07.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 07/11/2018] [Indexed: 11/17/2022]
Abstract
The ribbon isomer of α-conotoxin AuIB has 10-fold greater potency than the wild-type globular isomer at inhibiting nicotinic acetylcholine receptors (nAChRs) in rat parasympathetic neurons, and unlike its globular isoform, ribbon AuIB only targets a specific stoichiometry of the α3β4 nAChR subtype. Previous electrophysiological recordings of AuIB indicated that ribbon AuIB binds to the α3(+)α3(-) interface within the nAChR extracellular domain, which is displayed by the (α3)3(β4)2 stoichiometry but not by (α3)2(β4)3. This specificity for a particular stoichiometry is remarkable and suggests that ribbon isoforms of α-conotoxins might have great potential in drug design. In this study, we investigated the binding mode and structure-activity relationships of ribbon AuIB using a combination of molecular modeling and electrophysiology recording to determine the features that underpin its selectivity. An alanine scan showed that positions 4 and 9 of ribbon AuIB are the main determinants of the interaction with (α3)3(β4)2 nAChR. Our computational models indicate that the first loop of ribbon AuIB binds in the "aromatic box" of the acetylcholine orthosteric binding site, similar to that of globular AuIB. In contrast, the second loop and the termini of the ribbon isomer have different orientations and interactions in the binding sites to those of the globular isomer. The structure-activity relationships reported herein should be useful to design peptides displaying a ribbon α-conotoxin scaffold for inhibition of nAChR subtypes that have hitherto been difficult to selectively target.
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Affiliation(s)
- Xiaosa Wu
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Han-Shen Tae
- Illawarra Health and Medical Research Institute (IHMRI), The University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Yen-Hua Huang
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - David J Adams
- Illawarra Health and Medical Research Institute (IHMRI), The University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - David J Craik
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia.
| | - Quentin Kaas
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia.
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Abraham N, Lewis RJ. Neuronal Nicotinic Acetylcholine Receptor Modulators from Cone Snails. Mar Drugs 2018; 16:E208. [PMID: 29899286 PMCID: PMC6024932 DOI: 10.3390/md16060208] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 05/25/2018] [Accepted: 06/06/2018] [Indexed: 12/15/2022] Open
Abstract
Marine cone snails are a large family of gastropods that have evolved highly potent venoms for predation and defense. The cone snail venom has exceptional molecular diversity in neuropharmacologically active compounds, targeting a range of receptors, ion channels, and transporters. These conotoxins have helped to dissect the structure and function of many of these therapeutically significant targets in the central and peripheral nervous systems, as well as unravelling the complex cellular mechanisms modulated by these receptors and ion channels. This review provides an overview of α-conotoxins targeting neuronal nicotinic acetylcholine receptors. The structure and activity of both classical and non-classical α-conotoxins are discussed, along with their contributions towards understanding nicotinic acetylcholine receptor (nAChR) structure and function.
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Affiliation(s)
- Nikita Abraham
- IMB Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia.
| | - Richard J Lewis
- IMB Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia.
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Sajeevan KA, Roy D. Peptide Sequence and Solvent as Levers to Control Disulfide Connectivity in Multiple Cysteine Containing Venom Toxins. J Phys Chem B 2018; 122:5776-5789. [DOI: 10.1021/acs.jpcb.8b01437] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Karuna Anna Sajeevan
- Department of Chemistry, Birla Institute of Technology and Science-Pilani, Hyderabad Campus, Jawahar Nagar, Shameerpet Mandal, Hyderabad, Telangana 500078, India
| | - Durba Roy
- Department of Chemistry, Birla Institute of Technology and Science-Pilani, Hyderabad Campus, Jawahar Nagar, Shameerpet Mandal, Hyderabad, Telangana 500078, India
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Heimer P, Tietze AA, Bäuml CA, Resemann A, Mayer FJ, Suckau D, Ohlenschläger O, Tietze D, Imhof D. Conformational μ-Conotoxin PIIIA Isomers Revisited: Impact of Cysteine Pairing on Disulfide-Bond Assignment and Structure Elucidation. Anal Chem 2018; 90:3321-3327. [DOI: 10.1021/acs.analchem.7b04854] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Pascal Heimer
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
| | - Alesia A. Tietze
- Clemens Schöpf Institute of Organic Chemistry and Biochemistry, Darmstadt University of Technology, Alarich-Weiss-Strasse 4, D-64287 Darmstadt, Germany
| | - Charlotte A. Bäuml
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
| | - Anja Resemann
- MALDI Applications and Proteomics R&D, Bruker Daltonics GmbH, Fahrenheitstrasse 4, D-28359 Bremen, Germany
| | - Franz Josef Mayer
- MALDI Applications and Proteomics R&D, Bruker Daltonics GmbH, Fahrenheitstrasse 4, D-28359 Bremen, Germany
| | - Detlev Suckau
- MALDI Applications and Proteomics R&D, Bruker Daltonics GmbH, Fahrenheitstrasse 4, D-28359 Bremen, Germany
| | - Oliver Ohlenschläger
- Leibniz Institute on Aging − Fritz Lipmann Institute, Beutenbergstrasse 11, D-07745 Jena, Germany
| | - Daniel Tietze
- Eduard Zintl Institute of Inorganic and Physical Chemistry, Darmstadt University of Technology, Alarich-Weiss-Strasse 4, D-64287 Darmstadt, Germany
| | - Diana Imhof
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
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Aqueous ionic liquids influence the disulfide bond isoform equilibrium in conotoxin AuIB: a consequence of the Hofmeister effect? Biophys Rev 2018; 10:769-780. [PMID: 29294259 DOI: 10.1007/s12551-017-0391-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 12/13/2017] [Indexed: 12/13/2022] Open
Abstract
The appearance of several disulfide bond isoforms in multiple cysteine containing venom peptides poses a significant challenge in their synthesis and purification under laboratory conditions. Recent experiments suggest that careful tuning of solvent and temperature conditions can propel the disulfide bond isoform equilibrium in favor of the most potent, native form. Certain aqueous ionic liquids (ILs) have proven significantly useful as solvents for this purpose, while exceptions have also been noted. To elucidate the molecular level origin behind such a preference, we report a detailed explicit solvent replica exchange molecular dynamics study of a conotoxin, AuIB, in pure water and four different aqueous IL solutions (~45-60% v/v). The ILs studied here are comprised of cations like 1-ethyl-3-methyl-imidazolium (Im21+) or 1-butyl-3-methyl-imidazolium (Im41+) coupled with either acetate (OAc-) or chloride (Cl-) as the counter anion. Our simulations unfold interesting features of the conformational spaces sampled by the peptide and its solvation in pure water and aqueous IL solutions. Detailed investigation into populations of the globular disulfide bond isoform of AuIB in aqueous IL solutions reveal distinct trends which might be related to the Hofmeister effect of the cation and anion of the IL and of specific interactions of the aqueous IL solutions with the peptide. In accordance with experimental observations, the aqueous [Im21][OAc] solution is found to promote the highest globular isoform population in AuIB.
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α-Conotoxins to explore the molecular, physiological and pathophysiological functions of neuronal nicotinic acetylcholine receptors. Neurosci Lett 2017; 679:24-34. [PMID: 29199094 DOI: 10.1016/j.neulet.2017.11.063] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 11/28/2017] [Accepted: 11/29/2017] [Indexed: 12/22/2022]
Abstract
The vast diversity of neuronal nicotinic acetylcholine subunits expressed in the central and peripheral nervous systems, as well as in non-neuronal tissues, constitutes a formidable challenge for researchers and clinicians to decipher the role of particular subtypes, including complex subunit associations, in physiological and pathophysiological functions. Many natural products target the nAChRs, but there is no richer source of nicotinic ligands than the venom of predatory gastropods known as cone snails. Indeed, every single species of cone snail was shown to produce at least one type of such α-conotoxins. These tiny peptides (10-25 amino acids), constrained by disulfide bridges, proved to be unvaluable tools to investigate the structure and function of nAChRs, some of them having also therapeutic potential. In this review, we provide a recent update on the pharmacology and subtype specificity of several major α-conotoxins.
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Moreels L, Peigneur S, Yamaguchi Y, Vriens K, Waelkens E, Zhu S, Thevissen K, Cammue BPA, Sato K, Tytgat J. Expanding the pharmacological profile of κ-hefutoxin 1 and analogues: A focus on the inhibitory effect on the oncogenic channel K v10.1. Peptides 2017; 98:43-50. [PMID: 27578329 DOI: 10.1016/j.peptides.2016.08.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 08/21/2016] [Accepted: 08/23/2016] [Indexed: 10/21/2022]
Abstract
Peptide toxins, such as scorpion peptides, are interesting lead compounds in the search for novel drugs. In this paper, the focus is on the scorpion peptide κ-hefutoxin 1. This peptide displays a cysteine-stabilized helix-loop-helix fold (CSα/α) and is known to be a weak Kv1.x inhibitor. Due to the low affinity of κ-hefutoxin 1 for these channels, it is assumed that the main target(s) of κ-hefutoxin 1 remain(s) unknown. In order to identify novel targets, electrophysiological measurements and antifungal assays were performed. The effect of κ-hefutoxin 1 was previously evaluated on a panel of 11 different voltage-gated potassium channels. Here, we extended this target screening with the oncogenic potassium channel Kv10.1. κ-Hefutoxin 1 was able to inhibit this channel in a dose-dependent manner (IC50∼26μM). Although the affinity is rather low, this is the first peptide toxin ever described to be a Kv10.1 inhibitor. The structure-activity relationship of κ-hefutoxin 1 on Kv10.1 was investigated by testing eight κ-hefutoxin 1 variants using the two-electrode voltage clamp technique. Several important amino acid residues were identified; the functional dyad residues (Tyr5 and Lys19), N-terminal residues (Gly1 and His2) and the amidated C-terminal residue (Cys22). Since the CSα/α fold is also found in a class of antifungal plant peptides, the α-hairpinines, we investigated the antifungal activity of κ-hefutoxin 1. κ-Hefutoxin 1 showed low activity against the plant pathogen Fusarium culmorum and no activity against three other yeast and fungal species, even at high concentrations (∼100μM).
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Affiliation(s)
- Lien Moreels
- Toxicology and Pharmacology, KU Leuven, Campus Gasthuisberg O&N2, Herestraat 49, PO Box 922, 3000 Leuven, Belgium.
| | - Steve Peigneur
- Toxicology and Pharmacology, KU Leuven, Campus Gasthuisberg O&N2, Herestraat 49, PO Box 922, 3000 Leuven, Belgium.
| | - Yoko Yamaguchi
- Department of Environmental Science, Fukuoka Women's University, Fukuoka 813-8529, Japan.
| | - Kim Vriens
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, PO Box 2460, 3001 Leuven, Belgium.
| | - Etienne Waelkens
- Laboratory of Protein Phosphorylation and Proteomics, KU Leuven, Campus Gasthuisberg, O&N1, Herestraat 49, PO Box 901, 3000 Leuven, Belgium.
| | - Shunyi Zhu
- Group of Peptide Biology and Evolution, State Key Laboratory of Integrated Management of Pest Insects & Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
| | - Karin Thevissen
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, PO Box 2460, 3001 Leuven, Belgium.
| | - Bruno P A Cammue
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, PO Box 2460, 3001 Leuven, Belgium; VIB Department of Plant Systems Biology, Technologiepark 927, 9052 Ghent, Belgium.
| | - Kazuki Sato
- Department of Environmental Science, Fukuoka Women's University, Fukuoka 813-8529, Japan.
| | - Jan Tytgat
- Toxicology and Pharmacology, KU Leuven, Campus Gasthuisberg O&N2, Herestraat 49, PO Box 922, 3000 Leuven, Belgium.
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Zhangsun D, Zhu X, Kaas Q, Wu Y, Craik DJ, McIntosh JM, Luo S. αO-Conotoxin GeXIVA disulfide bond isomers exhibit differential sensitivity for various nicotinic acetylcholine receptors but retain potency and selectivity for the human α9α10 subtype. Neuropharmacology 2017; 127:243-252. [PMID: 28416445 PMCID: PMC6029978 DOI: 10.1016/j.neuropharm.2017.04.015] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2017] [Revised: 03/14/2017] [Accepted: 04/11/2017] [Indexed: 11/30/2022]
Abstract
Nicotinic acetylcholine receptor (nAChR) subtypes exhibit distinct neuropharmacological properties that are involved in a range of neuropathological conditions, including pain, addiction, epilepsy, autism, schizophrenia, Tourette's syndrome, Alzheimer's and Parkinson's diseases, as well as many types of cancer. The α9α10 nAChR is a potential target in chronic pain, wound healing, the pathophysiology of the auditory system, and breast and lung cancers. αO-conotoxin GeXIVA is a potent antagonist of rat α9α10 nAChRs, with the 'bead' disulfide bond isomer displaying the lowest IC50 of the three possible isomers. In the rat chronic constriction injury model of neuropathic pain, this isomer reduced mechanical hyperalgesia without affecting motor performance. Here, we report the effects of the three disulfide bond isomers of GeXIVA on human α9α10 nAChRs, other human nAChR subtypes, various rat nAChR subtypes, and 10 rat α9α10 nAChR mutants. The three isomers displayed only ∼5-fold difference in potency on the human vs rat α9α10 receptors and had similar affinities at wild-type rat α9α10 nAChRs and all 10 α9α10 receptor mutants. From these findings, the binding site and mechanism of action of GeXIVA on rat and human α9α10 nAChR was deduced to be different from that of other conotoxins targeting this nAChR subtype. GeXIVA is therefore a unique ligand that might prove useful for further probing of binding sites on the α9α10 nAChR. This article is part of the Special Issue entitled 'Venom-derived Peptides as Pharmacological Tools.'
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Affiliation(s)
- Dongting Zhangsun
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Key Laboratory for Marine Drug of Haikou, Hainan University, Haikou, Hainan, 570228 China
| | - Xiaopeng Zhu
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Key Laboratory for Marine Drug of Haikou, Hainan University, Haikou, Hainan, 570228 China
| | - Quentin Kaas
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072 Australia
| | - Yong Wu
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Key Laboratory for Marine Drug of Haikou, Hainan University, Haikou, Hainan, 570228 China
| | - David J Craik
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072 Australia
| | - J Michael McIntosh
- Department of Biology and Psychiatry, University of Utah, Salt Lake City, UT 84112, USA; George E. Wahlen Department of Veterans Affairs Medical Center, Salt Lake City, UT, 84108, USA
| | - Sulan Luo
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Key Laboratory for Marine Drug of Haikou, Hainan University, Haikou, Hainan, 570228 China.
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Tabassum N, Tae HS, Jia X, Kaas Q, Jiang T, Adams DJ, Yu R. Role of Cys I-Cys III Disulfide Bond on the Structure and Activity of α-Conotoxins at Human Neuronal Nicotinic Acetylcholine Receptors. ACS OMEGA 2017; 2:4621-4631. [PMID: 30023726 PMCID: PMC6044955 DOI: 10.1021/acsomega.7b00639] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 08/04/2017] [Indexed: 06/08/2023]
Abstract
α-Conotoxins preferentially antagonize muscle and neuronal nicotinic acetylcholine receptors (nAChRs). Native α-conotoxins have two disulfide links, CI-CIII and CII-CIV, and owing to the inherent properties of disulfide bonds, α-conotoxins have been systematically engineered to improve their chemical and biological properties. In this study, we explored the possibility of simplifying the disulfide framework of α-conotoxins Vc1.1, BuIA, ImI, and AuIB, by introducing [C2H,C8F] modification to the CI-CIII bond. We therefore explored the possibility of using hydrophobic packing of standard amino acid side chains to replace disulfide bonds as an alternative strategy to nonnatural amino acid cross-links. The impact of CI-CIII disulfide bond replacement on the conformation of the α-conotoxins was investigated using molecular dynamics (MD) simulations and nuclear magnetic resonance chemical shift index study. Two-electrode voltage clamp techniques and MD simulations were used to study the impact of disulfide bond deletion on the activities of the peptides at human neuronal nAChRs. All disulfide-deleted variants except ImI[C2H,C8F] had reduced potency for inhibiting nAChRs. Our results suggest that the CI-CIII disulfide bond is important to stabilize the secondary structure of α-conotoxins as well as their interaction with neuronal nAChR targets. Results from this study enrich our understanding of the function of the CI-CIII disulfide bond and are useful in guiding future structural engineering of the α-conotoxins.
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Affiliation(s)
- Nargis Tabassum
- Key
Laboratory of Marine Drugs, Chinese Ministry of Education, School
of Medicine and Pharmacy, Ocean University
of China, Qingdao 266003, China
- Laboratory
for Marine Drugs and Bioproducts of Qingdao National Laboratory for
Marine Science and Technology, Qingdao 266003, China
| | - Han-Shen Tae
- Illawarra
Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Xinying Jia
- The Centre for Advanced Imaging and Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072 Australia
| | - Quentin Kaas
- The Centre for Advanced Imaging and Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072 Australia
| | - Tao Jiang
- Key
Laboratory of Marine Drugs, Chinese Ministry of Education, School
of Medicine and Pharmacy, Ocean University
of China, Qingdao 266003, China
| | - David J. Adams
- Illawarra
Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Rilei Yu
- Key
Laboratory of Marine Drugs, Chinese Ministry of Education, School
of Medicine and Pharmacy, Ocean University
of China, Qingdao 266003, China
- Laboratory
for Marine Drugs and Bioproducts of Qingdao National Laboratory for
Marine Science and Technology, Qingdao 266003, China
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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.'
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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
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Molecular Engineering of Conus Peptides as Therapeutic Leads. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1030:229-254. [DOI: 10.1007/978-3-319-66095-0_10] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Sajeevan KA, Roy D. Temperature-dependent molecular dynamics study reveals an ionic liquid induced 3 10 - to α-helical switch in a neurotoxin. Biopolymers 2016; 108. [PMID: 28009043 DOI: 10.1002/bip.23009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 11/29/2016] [Accepted: 12/06/2016] [Indexed: 02/01/2023]
Abstract
Thermal melting and recooling of AuIB, a neurotoxic conopeptide and a highly potent nonaddictive pain reliever is investigated thoroughly in water and an ionic liquid (IL) 1-butyl-3-methylimidazolium Chloride, [Im41 ][Cl] by classical molecular dynamics simulations. Structural evolution of AuIB in water and the IL is observed at different temperatures between 305 and 400 K, to explore how highly viscous ionic solvents affect the peptide structure as compared to conventional solvent water. At 305 K, unlike water, the coercive effect of IL frustrates AuIB secondary structural motifs significantly. As the temperature is raised, a very interesting IL induced conformational transition from 310 - to α-helix is noticed in the peptide, presumably triggered by a significant restructuring of the peptide H-bond network. The backbone length distributions of the peptide indicate that the IL induced conformational switching is accompanied by a reduction of the axial rise of the helical region, encompassing the residues Pro-6 to Ala-10. Further, we estimated the void space available to the peptide for its structural relaxation within the first solvation shell of ∼5 Å in water as well as in IL. A temperature increase by 100 K, opens up an estimated void volume of ∼70 Å3 , equivalent to the volume of approximately six water molecules, around the peptide in IL. Cooling simulations of AuIB point to the crucial interplay between thermodynamically favored AuIB conformers and their kinetic control. This study provides a comprehensive understanding of the ionic solvation of biomolecules reinforcing previous experimental findings.
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Affiliation(s)
- Karuna Anna Sajeevan
- Department of Chemistry, Birla Institute of Technology and Science-Pilani, Hyderabad, Campus, Jawahar Nagar, Shameerpet Mandal, Hyderabad, Telangana, 500078, India
| | - Durba Roy
- Department of Chemistry, Birla Institute of Technology and Science-Pilani, Hyderabad, Campus, Jawahar Nagar, Shameerpet Mandal, Hyderabad, Telangana, 500078, India
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Carstens BB, Swedberg J, Berecki G, Adams DJ, Craik DJ, Clark RJ. Effects of linker sequence modifications on the structure, stability, and biological activity of a cyclic α-conotoxin. Biopolymers 2016; 106:864-875. [DOI: 10.1002/bip.22848] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 03/28/2016] [Indexed: 12/19/2022]
Affiliation(s)
- Bodil B. Carstens
- Institute for Molecular Bioscience, the University of Queensland; Brisbane Queensland 4072 Australia
- School of Biomedical Sciences; the University of Queensland; Brisbane Queensland 4072 Australia
| | - Joakim Swedberg
- Institute for Molecular Bioscience, the University of Queensland; Brisbane Queensland 4072 Australia
| | - Géza Berecki
- Health Innovations Research Institute, RMIT University; Melbourne Victoria 3083 Australia
| | - David J. Adams
- Health Innovations Research Institute, RMIT University; Melbourne Victoria 3083 Australia
| | - David J. Craik
- Institute for Molecular Bioscience, the University of Queensland; Brisbane Queensland 4072 Australia
| | - Richard J. Clark
- School of Biomedical Sciences; the University of Queensland; Brisbane Queensland 4072 Australia
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Barkan DT, Cheng XL, Celino H, Tran TT, Bhandari A, Craik CS, Sali A, Smythe ML. Clustering of disulfide-rich peptides provides scaffolds for hit discovery by phage display: application to interleukin-23. BMC Bioinformatics 2016; 17:481. [PMID: 27881076 PMCID: PMC5120537 DOI: 10.1186/s12859-016-1350-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 11/10/2016] [Indexed: 03/01/2023] Open
Abstract
BACKGROUND Disulfide-rich peptides (DRPs) are found throughout nature. They are suitable scaffolds for drug development due to their small cores, whose disulfide bonds impart extraordinary chemical and biological stability. A challenge in developing a DRP therapeutic is to engineer binding to a specific target. This challenge can be overcome by (i) sampling the large sequence space of a given scaffold through a phage display library and by (ii) panning multiple libraries encoding structurally distinct scaffolds. Here, we implement a protocol for defining these diverse scaffolds, based on clustering structurally defined DRPs according to their conformational similarity. RESULTS We developed and applied a hierarchical clustering protocol based on DRP structural similarity, followed by two post-processing steps, to classify 806 unique DRP structures into 81 clusters. The 20 most populated clusters comprised 85% of all DRPs. Representative scaffolds were selected from each of these clusters; the representatives were structurally distinct from one another, but similar to other DRPs in their respective clusters. To demonstrate the utility of the clusters, phage libraries were constructed for three of the representative scaffolds and panned against interleukin-23. One library produced a peptide that bound to this target with an IC50 of 3.3 μM. CONCLUSIONS Most DRP clusters contained members that were diverse in sequence, host organism, and interacting proteins, indicating that cluster members were functionally diverse despite having similar structure. Only 20 peptide scaffolds accounted for most of the natural DRP structural diversity, providing suitable starting points for seeding phage display experiments. Through selection of the scaffold surface to vary in phage display, libraries can be designed that present sequence diversity in architecturally distinct, biologically relevant combinations of secondary structures. We supported this hypothesis with a proof-of-concept experiment in which three phage libraries were constructed and panned against the IL-23 target, resulting in a single-digit μM hit and suggesting that a collection of libraries based on the full set of 20 scaffolds increases the potential to identify efficiently peptide binders to a protein target in a drug discovery program.
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Affiliation(s)
- David T Barkan
- Protagonist Therapeutics, Inc., 521 Cottonwood Drive, Suite 100, Milpitas, CA, 95035-74521, USA
| | - Xiao-Li Cheng
- Protagonist Therapeutics, Inc., 521 Cottonwood Drive, Suite 100, Milpitas, CA, 95035-74521, USA
| | - Herodion Celino
- Protagonist Therapeutics, Inc., 521 Cottonwood Drive, Suite 100, Milpitas, CA, 95035-74521, USA
| | - Tran T Tran
- Protagonist Therapeutics, Inc., 521 Cottonwood Drive, Suite 100, Milpitas, CA, 95035-74521, USA
| | - Ashok Bhandari
- Protagonist Therapeutics, Inc., 521 Cottonwood Drive, Suite 100, Milpitas, CA, 95035-74521, USA
| | - Charles S Craik
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA, 94158, USA.,California Institute for Quantitative Biosciences (QB3), University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Andrej Sali
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, 94158, USA.,Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA, 94158, USA.,California Institute for Quantitative Biosciences (QB3), University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Mark L Smythe
- Protagonist Therapeutics, Inc., 521 Cottonwood Drive, Suite 100, Milpitas, CA, 95035-74521, USA. .,Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Qld, 4072, Australia.
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Román-González SA, Robles-Gómez EE, Reyes J, Bernáldez J, Cortés-Guzmán F, Martínez-Mayorga K, Lazcano-Pérez F, Licea A, Arreguín-Espinosa R. A 3D structural model of RsXXVIA, an ω-conotoxin. Struct Chem 2016. [DOI: 10.1007/s11224-016-0877-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Albert A, Eksteen JJ, Isaksson J, Sengee M, Hansen T, Vasskog T. General Approach To Determine Disulfide Connectivity in Cysteine-Rich Peptides by Sequential Alkylation on Solid Phase and Mass Spectrometry. Anal Chem 2016; 88:9539-9546. [DOI: 10.1021/acs.analchem.6b02115] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
| | | | - Johan Isaksson
- Department
of Chemistry, Faculty of Science and Technology, UiT The Arctic University of Norway, 9037 Tromsø, Norway
| | | | - Terkel Hansen
- Department
of Pharmacy, Faculty of Health Sciences, UiT The Arctic University of Norway, 9037 Tromsø, Norway
| | - Terje Vasskog
- Norut Northern Research Institute, 9294 Tromsø, Norway
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Yamaguchi Y, Peigneur S, Liu J, Uemura S, Nose T, Nirthanan S, Gopalakrishnakone P, Tytgat J, Sato K. Role of individual disulfide bridges in the conformation and activity of spinoxin (α-KTx6.13), a potassium channel toxin from Heterometrus spinifer scorpion venom. Toxicon 2016; 122:31-38. [PMID: 27660193 DOI: 10.1016/j.toxicon.2016.09.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 09/15/2016] [Accepted: 09/17/2016] [Indexed: 01/01/2023]
Abstract
Spinoxin (SPX; α-KTx6.13), isolated from venom of the scorpion Heterometrus spinifer, is a K+ channel-specific peptide toxin (KTx), which adopts a cysteine-stabilized α/β scaffold that is cross-linked by four disulfide bridges (Cys1-Cys5, Cys2-Cys6, Cys3-Cys7, and Cys4-Cys8). To investigate the role of the individual disulfide bonds in the structure-activity relationship of SPX, we synthesized four SPX analogs in which each pair of cysteine residues was replaced by alanine residues. The analysis of circular dichroism spectra and inhibitory activity against Kv1.3 channels showed that the SPX analogs lacking any of three specific disulfide bonds (Cys1-Cys5, Cys2-Cys6, and Cys3-Cys7) were unable to form the native secondary structure and completely lost inhibitory activities. Thus, we conclude that Cys1-Cys5, Cys2-Cys6, and Cys3-Cys7 are required for the inhibition of the Kv1.3 channel by SPX. In contrast, the analog lacking Cys4-Cys8 retained both native secondary structure and inhibitory activity. Interestingly, one of the isomers of the analog lacking Cys1-Cys5 also showed inhibitory activities, although its inhibition was ∼18-fold weaker than native SPX. This isomer had an atypical disulfide bond pairing (Cys3-Cys4 and Cys7-Cys8) that corresponds to that of maurotoxin (MTX), another α-KTx6 family member. These results indicate that the Cys1-Cys5 and Cys2-Cys6 bonds are important for restricting the toxin from forming an atypical (MTX-type) disulfide bond pairing among the remaining four cysteine residues (Cys3, Cys4, Cys7, and Cys8) in native SPX.
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Affiliation(s)
- Yoko Yamaguchi
- Department of Environment Sciences, Fukuoka Women's University, Fukuoka, 813-8529, Japan
| | - Steve Peigneur
- Toxicology and Pharmacology, University of Leuven, Campus Gasthuisberg O&N2, Herestraat 49, P.O. Box 922, Leuven, 3000, Belgium
| | - Junyi Liu
- Department of Environment Sciences, Fukuoka Women's University, Fukuoka, 813-8529, Japan
| | - Shiho Uemura
- Department of Environment Sciences, Fukuoka Women's University, Fukuoka, 813-8529, Japan
| | - Takeru Nose
- Faculty of Arts and Science, Kyushu University, Fukuoka, 819-0395, Japan
| | - Selvanayagam Nirthanan
- School of Medicine, Griffith University, Gold Coast, Queensland, 4222, Australia; School of Medical Science, Griffith University, Gold Coast, Queensland, 4222, Australia; Menzies Health Institute Queensland, Gold Coast, Australia
| | - Ponnampalam Gopalakrishnakone
- Venom and Toxin Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore
| | - Jan Tytgat
- Toxicology and Pharmacology, University of Leuven, Campus Gasthuisberg O&N2, Herestraat 49, P.O. Box 922, Leuven, 3000, Belgium
| | - Kazuki Sato
- Department of Environment Sciences, Fukuoka Women's University, Fukuoka, 813-8529, Japan.
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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.
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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.
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42
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Wu X, Huang Y, Kaas Q, Craik DJ. Cyclisation of Disulfide‐Rich Conotoxins in Drug Design Applications. European J Org Chem 2016. [DOI: 10.1002/ejoc.201600402] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Xiaosa Wu
- Institute for Molecular BioscienceThe University of Queensland306 Carmody Road (Building 80)4072BrisbaneAustralia
| | - Yen‐Hua Huang
- Institute for Molecular BioscienceThe University of Queensland306 Carmody Road (Building 80)4072BrisbaneAustralia
| | - Quentin Kaas
- Institute for Molecular BioscienceThe University of Queensland306 Carmody Road (Building 80)4072BrisbaneAustralia
| | - David J. Craik
- Institute for Molecular BioscienceThe University of Queensland306 Carmody Road (Building 80)4072BrisbaneAustralia
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43
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Roy D, Lakshminarayanan M. Scrambling of disulfide bond scaffolds in neurotoxin AuIB: A molecular dynamics simulation study. Biopolymers 2016; 106:196-209. [DOI: 10.1002/bip.22799] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 12/05/2015] [Accepted: 12/18/2015] [Indexed: 12/13/2022]
Affiliation(s)
- Durba Roy
- Department of Chemistry; Birla Institute of Technology and Science-Pilani; Hyderabad Campus, Jawahar Nagar, Shameerpet Mandal Hyderabad Telangana 500078 India
| | - Madhavkrishnan Lakshminarayanan
- Department of Chemistry; Birla Institute of Technology and Science-Pilani; Hyderabad Campus, Jawahar Nagar, Shameerpet Mandal Hyderabad Telangana 500078 India
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44
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Carstens BB, Berecki G, Daniel JT, Lee HS, Jackson KAV, Tae H, Sadeghi M, Castro J, O'Donnell T, Deiteren A, Brierley SM, Craik DJ, Adams DJ, Clark RJ. Structure–Activity Studies of Cysteine‐Rich α‐Conotoxins that Inhibit High‐Voltage‐Activated Calcium Channels via GABA
B
Receptor Activation Reveal a Minimal Functional Motif. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201600297] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Bodil B. Carstens
- Institute for Molecular Biosciences The University of Queensland Brisbane Qld 4072 Australia
| | - Géza Berecki
- Health Innovations Research Institute RMIT University Melbourne Vic 3083 Australia
| | - James T. Daniel
- School of Biomedical Science The University of Queensland Brisbane Qld 4072 Australia
| | - Han Siean Lee
- School of Biomedical Science The University of Queensland Brisbane Qld 4072 Australia
| | - Kathryn A. V. Jackson
- School of Biomedical Science The University of Queensland Brisbane Qld 4072 Australia
| | - Han‐Shen Tae
- Health Innovations Research Institute RMIT University Melbourne Vic 3083 Australia
- Illawarra Health and Medical Research Institute (IHMRI) University of Wollongong Wollongong NSW 2522 Australia
| | - Mahsa Sadeghi
- Health Innovations Research Institute RMIT University Melbourne Vic 3083 Australia
- Illawarra Health and Medical Research Institute (IHMRI) University of Wollongong Wollongong NSW 2522 Australia
| | - Joel Castro
- Visceral Pain Group, Centre for Nutrition and Gastrointestinal Diseases Discipline of Medicine The University of Adelaide South Australian Health and Medical Research Institute (SAHMRI) Adelaide SA 5000 Australia
| | - Tracy O'Donnell
- Visceral Pain Group, Centre for Nutrition and Gastrointestinal Diseases Discipline of Medicine The University of Adelaide South Australian Health and Medical Research Institute (SAHMRI) Adelaide SA 5000 Australia
| | - Annemie Deiteren
- Visceral Pain Group, Centre for Nutrition and Gastrointestinal Diseases Discipline of Medicine The University of Adelaide South Australian Health and Medical Research Institute (SAHMRI) Adelaide SA 5000 Australia
| | - Stuart M. Brierley
- Visceral Pain Group, Centre for Nutrition and Gastrointestinal Diseases Discipline of Medicine The University of Adelaide South Australian Health and Medical Research Institute (SAHMRI) Adelaide SA 5000 Australia
| | - David J. Craik
- Institute for Molecular Biosciences The University of Queensland Brisbane Qld 4072 Australia
| | - David J. Adams
- Health Innovations Research Institute RMIT University Melbourne Vic 3083 Australia
- Illawarra Health and Medical Research Institute (IHMRI) University of Wollongong Wollongong NSW 2522 Australia
| | - Richard J. Clark
- School of Biomedical Science The University of Queensland Brisbane Qld 4072 Australia
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45
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Carstens BB, Berecki G, Daniel JT, Lee HS, Jackson KAV, Tae H, Sadeghi M, Castro J, O'Donnell T, Deiteren A, Brierley SM, Craik DJ, Adams DJ, Clark RJ. Structure–Activity Studies of Cysteine‐Rich α‐Conotoxins that Inhibit High‐Voltage‐Activated Calcium Channels via GABA
B
Receptor Activation Reveal a Minimal Functional Motif. Angew Chem Int Ed Engl 2016; 55:4692-6. [DOI: 10.1002/anie.201600297] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Indexed: 01/29/2023]
Affiliation(s)
- Bodil B. Carstens
- Institute for Molecular Biosciences The University of Queensland Brisbane Qld 4072 Australia
| | - Géza Berecki
- Health Innovations Research Institute RMIT University Melbourne Vic 3083 Australia
| | - James T. Daniel
- School of Biomedical Science The University of Queensland Brisbane Qld 4072 Australia
| | - Han Siean Lee
- School of Biomedical Science The University of Queensland Brisbane Qld 4072 Australia
| | - Kathryn A. V. Jackson
- School of Biomedical Science The University of Queensland Brisbane Qld 4072 Australia
| | - Han‐Shen Tae
- Health Innovations Research Institute RMIT University Melbourne Vic 3083 Australia
- Illawarra Health and Medical Research Institute (IHMRI) University of Wollongong Wollongong NSW 2522 Australia
| | - Mahsa Sadeghi
- Health Innovations Research Institute RMIT University Melbourne Vic 3083 Australia
- Illawarra Health and Medical Research Institute (IHMRI) University of Wollongong Wollongong NSW 2522 Australia
| | - Joel Castro
- Visceral Pain Group, Centre for Nutrition and Gastrointestinal Diseases Discipline of Medicine The University of Adelaide South Australian Health and Medical Research Institute (SAHMRI) Adelaide SA 5000 Australia
| | - Tracy O'Donnell
- Visceral Pain Group, Centre for Nutrition and Gastrointestinal Diseases Discipline of Medicine The University of Adelaide South Australian Health and Medical Research Institute (SAHMRI) Adelaide SA 5000 Australia
| | - Annemie Deiteren
- Visceral Pain Group, Centre for Nutrition and Gastrointestinal Diseases Discipline of Medicine The University of Adelaide South Australian Health and Medical Research Institute (SAHMRI) Adelaide SA 5000 Australia
| | - Stuart M. Brierley
- Visceral Pain Group, Centre for Nutrition and Gastrointestinal Diseases Discipline of Medicine The University of Adelaide South Australian Health and Medical Research Institute (SAHMRI) Adelaide SA 5000 Australia
| | - David J. Craik
- Institute for Molecular Biosciences The University of Queensland Brisbane Qld 4072 Australia
| | - David J. Adams
- Health Innovations Research Institute RMIT University Melbourne Vic 3083 Australia
- Illawarra Health and Medical Research Institute (IHMRI) University of Wollongong Wollongong NSW 2522 Australia
| | - Richard J. Clark
- School of Biomedical Science The University of Queensland Brisbane Qld 4072 Australia
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Prashanth JR, Dutertre S, Jin AH, Lavergne V, Hamilton B, Cardoso FC, Griffin J, Venter DJ, Alewood PF, Lewis RJ. The role of defensive ecological interactions in the evolution of conotoxins. Mol Ecol 2016; 25:598-615. [PMID: 26614983 DOI: 10.1111/mec.13504] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 11/23/2015] [Accepted: 11/24/2015] [Indexed: 10/22/2022]
Abstract
Venoms comprise of complex mixtures of peptides evolved for predation and defensive purposes. Remarkably, some carnivorous cone snails can inject two distinct venoms in response to predatory or defensive stimuli, providing a unique opportunity to study separately how different ecological pressures contribute to toxin diversification. Here, we report the extraordinary defensive strategy of the Rhizoconus subgenus of cone snails. The defensive venom from this worm-hunting subgenus is unusually simple, almost exclusively composed of αD-conotoxins instead of the ubiquitous αA-conotoxins found in the more complex defensive venom of mollusc- and fish-hunting cone snails. A similarly compartmentalized venom gland as those observed in the other dietary groups facilitates the deployment of this defensive venom. Transcriptomic analysis of a Conus vexillum venom gland revealed the αD-conotoxins as the major transcripts, with lower amounts of 15 known and four new conotoxin superfamilies also detected with likely roles in prey capture. Our phylogenetic and molecular evolution analysis of the αD-conotoxins from five subgenera of cone snails suggests they evolved episodically as part of a defensive strategy in the Rhizoconus subgenus. Thus, our results demonstrate an important role for defence in the evolution of conotoxins.
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Affiliation(s)
- J R Prashanth
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia
| | - S Dutertre
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia.,Institut des Biomolécules Max Mousseron, UMR 5247, Université Montpellier-CNRS, Place Eugène Bataillon, 34095, Montpellier Cedex 5, France
| | - A H Jin
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia
| | - V Lavergne
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia
| | - B Hamilton
- Pathology, Mater Health Services, Raymond Terrace, South Brisbane, Qld, 4101, Australia.,Mater Research Institute, The University of Queensland, St. Lucia, Qld, 4072, Australia
| | - F C Cardoso
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia
| | - J Griffin
- ACRF Microscopy Facility, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia
| | - D J Venter
- Pathology, Mater Health Services, Raymond Terrace, South Brisbane, Qld, 4101, Australia.,Mater Research Institute, The University of Queensland, St. Lucia, Qld, 4072, Australia.,School of Medicine, The University of Queensland, Brisbane, Qld, 4072, Australia
| | - P F Alewood
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia
| | - R J Lewis
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia
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Cloning, synthesis, and characterization of αO-conotoxin GeXIVA, a potent α9α10 nicotinic acetylcholine receptor antagonist. Proc Natl Acad Sci U S A 2015; 112:E4026-35. [PMID: 26170295 DOI: 10.1073/pnas.1503617112] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We identified a previously unidentified conotoxin gene from Conus generalis whose precursor signal sequence has high similarity to the O1-gene conotoxin superfamily. The predicted mature peptide, αO-conotoxin GeXIVA (GeXIVA), has four Cys residues, and its three disulfide isomers were synthesized. Previously pharmacologically characterized O1-superfamily peptides, exemplified by the US Food and Drug Administration-approved pain medication, ziconotide, contain six Cys residues and are calcium, sodium, or potassium channel antagonists. However, GeXIVA did not inhibit calcium channels but antagonized nicotinic AChRs (nAChRs), most potently on the α9α10 nAChR subtype (IC50 = 4.6 nM). Toxin blockade was voltage-dependent, and kinetic analysis of toxin dissociation indicated that the binding site of GeXIVA does not overlap with the binding site of the competitive antagonist α-conotoxin RgIA. Surprisingly, the most active disulfide isomer of GeXIVA is the bead isomer, comprising, according to NMR analysis, two well-resolved but uncoupled disulfide-restrained loops. The ribbon isomer is almost as potent but has a more rigid structure built around a short 310-helix. In contrast to most α-conotoxins, the globular isomer is the least potent and has a flexible, multiconformational nature. GeXIVA reduced mechanical hyperalgesia in the rat chronic constriction injury model of neuropathic pain but had no effect on motor performance, warranting its further investigation as a possible therapeutic agent.
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48
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Structure and function of μ-conotoxins, peptide-based sodium channel blockers with analgesic activity. Future Med Chem 2015; 6:1677-98. [PMID: 25406007 DOI: 10.4155/fmc.14.107] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
μ-Conotoxins block voltage-gated sodium channels (VGSCs) and compete with tetrodotoxin for binding to the sodium conductance pore. Early efforts identified µ-conotoxins that preferentially blocked the skeletal muscle subtype (NaV1.4). However, the last decade witnessed a significant increase in the number of µ-conotoxins and the range of VGSC subtypes inhibited (NaV1.2, NaV1.3 or NaV1.7). Twenty µ-conotoxin sequences have been identified to date and structure-activity relationship studies of several of these identified key residues responsible for interactions with VGSC subtypes. Efforts to engineer-in subtype specificity are driven by in vivo analgesic and neuromuscular blocking activities. This review summarizes structural and pharmacological studies of µ-conotoxins, which show promise for development of selective blockers of NaV1.2, and perhaps also NaV1.1,1.3 or 1.7.
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Abstract
INTRODUCTION Conotoxins are a large family of bioactive peptides derived from cone snail venom. They target specific classes of ion channels and other membrane proteins and may have therapeutic value, primarily in the management of pain. AREAS COVERED The authors surveyed the US patent literature covering conotoxins, and their potential therapeutic applications. They describe the various subclasses of conotoxins that are the subject of current patent applications and their therapeutic indications. Limitations that may preclude broader application of these molecules are discussed and strategies for overcoming these limitations are presented. EXPERT OPINION Despite more than 25 years of intense global conotoxin research, only one molecule has successfully reached the market. Several other conotoxin-derived candidates failed in clinical trials, indicating that 'from the bench into the clinic' translation has been more difficult than originally anticipated. Nevertheless, we are optimistic that the potent activities of these molecules and the potential for improving their biopharmaceutical properties may lead to next-generation drug candidates with favorable pharmacological properties.
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Affiliation(s)
- Thomas Durek
- a The University of Queensland, Institute for Molecular Bioscience , Brisbane 4072, QLD, Australia
| | - David J Craik
- a The University of Queensland, Institute for Molecular Bioscience , Brisbane 4072, QLD, Australia
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50
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Bioinformatics-Aided Venomics. Toxins (Basel) 2015; 7:2159-87. [PMID: 26110505 PMCID: PMC4488696 DOI: 10.3390/toxins7062159] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Revised: 06/03/2015] [Accepted: 06/05/2015] [Indexed: 12/12/2022] Open
Abstract
Venomics is a modern approach that combines transcriptomics and proteomics to explore the toxin content of venoms. This review will give an overview of computational approaches that have been created to classify and consolidate venomics data, as well as algorithms that have helped discovery and analysis of toxin nucleic acid and protein sequences, toxin three-dimensional structures and toxin functions. Bioinformatics is used to tackle specific challenges associated with the identification and annotations of toxins. Recognizing toxin transcript sequences among second generation sequencing data cannot rely only on basic sequence similarity because toxins are highly divergent. Mass spectrometry sequencing of mature toxins is challenging because toxins can display a large number of post-translational modifications. Identifying the mature toxin region in toxin precursor sequences requires the prediction of the cleavage sites of proprotein convertases, most of which are unknown or not well characterized. Tracing the evolutionary relationships between toxins should consider specific mechanisms of rapid evolution as well as interactions between predatory animals and prey. Rapidly determining the activity of toxins is the main bottleneck in venomics discovery, but some recent bioinformatics and molecular modeling approaches give hope that accurate predictions of toxin specificity could be made in the near future.
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