1
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Koehbach J, Muratspahić E, Ahmed ZM, White AM, Tomašević N, Durek T, Clark RJ, Gruber CW, Craik DJ. Chemical synthesis of grafted cyclotides using a "plug and play" approach. RSC Chem Biol 2024; 5:567-571. [PMID: 38846076 PMCID: PMC11151825 DOI: 10.1039/d4cb00008k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 04/23/2024] [Indexed: 06/09/2024] Open
Abstract
Cyclotides are a diverse class of plant-derived cyclic, disulfide-rich peptides with a unique cyclic cystine knot topology. Their remarkable structural stability and resistance to proteolytic degradation can lead to improved pharmacokinetics and oral activity as well as selectivity and high enzymatic stability. Thus, cyclotides have emerged as powerful scaffold molecules for designing peptide-based therapeutics. The chemical engineering of cyclotides has generated novel peptide ligands of G protein-coupled receptors (GPCRs), today's most exploited drug targets. However key challenges potentially limit the widespread use of cyclotides in molecular grafting applications. Folding of cyclotides containing bioactive epitopes remains a major bottleneck in cyclotide synthesis. Here we present a modular 'plug and play' approach that effectively bypasses problems associated with the oxidative folding of cyclotides. By grafting onto a pre-formed acyclic cyclotide-like scaffold we show that difficult-to-graft sequences can be easily obtained and can target GPCRs with nanomolar affinities and potencies. We further show the suitability of this new method to graft other complex epitopes including structures with additional disulfide bonds that are not readily available via currently employed chemical methods, thus fully unlocking cyclotides to be used in drug design applications.
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Affiliation(s)
- Johannes Koehbach
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland Brisbane Queensland Australia
- School of Biomedical Sciences, The University of Queensland Brisbane Queensland Australia
| | - Edin Muratspahić
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna Vienna Austria
| | - Zakaria M Ahmed
- School of Biomedical Sciences, The University of Queensland Brisbane Queensland Australia
| | - Andrew M White
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland Brisbane Queensland Australia
- Research School of Chemistry, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, Australian National University Australia
| | - Nataša Tomašević
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna Vienna Austria
| | - Thomas Durek
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland Brisbane Queensland Australia
| | - Richard J Clark
- School of Biomedical Sciences, The University of Queensland Brisbane Queensland Australia
| | - Christian W Gruber
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna Vienna Austria
| | - David J Craik
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland Brisbane Queensland Australia
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2
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Muratspahić E, Aslanoglou D, White AM, Draxler C, Kozisek X, Farooq Z, Craik DJ, McCormick PJ, Durek T, Gruber CW. Development of Melanocortin 4 Receptor Agonists by Exploiting Animal-Derived Macrocyclic, Disulfide-Rich Peptide Scaffolds. ACS Pharmacol Transl Sci 2023; 6:1373-1381. [PMID: 37854631 PMCID: PMC10580383 DOI: 10.1021/acsptsci.3c00090] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Indexed: 10/20/2023]
Abstract
G protein-coupled receptors are among the most widely studied classes of drug targets. A major challenge in this field is to develop ligands that will selectively modulate a single receptor subtype to overcome the disadvantages of undesired "off target" effects caused by lack of target and thus signaling specificity. In the current study, we explored ligand design for the melanocortin 4 receptor (MC4R) since it is an attractive target for developing antiobesity drugs. Endogenously, the receptor is activated by peptide ligands, i.e., three melanocyte-stimulating hormones (α-MSH, β-MSH, and γ-MSH) and by adrenocorticotropic hormone. Therefore, we utilized a peptide drug design approach, utilizing "molecular grafting" of pharmacophore peptide sequence motifs onto a stable nature-derived peptide scaffold. Specifically, protegrin-4-like-peptide-1 (Pr4LP1) and arenicin-1-like-peptide-1 (Ar3LP1) fully activated MC4R in a functional cAMP assay with potencies of 3.7 and 1.0 nM, respectively. In a nanoluciferase complementation assay with less signal amplification, the designed peptides fully recruited mini-Gs with subnanomolar and nanomolar potencies. Interestingly, these novel peptide MC4R ligands recruited β-arrestin-2 with ∼2-fold greater efficacies and ∼20-fold increased potencies as compared to the endogenous α-MSH. The peptides were inactive at related MC1R and MC3R in a cAMP accumulation assay. These findings highlight the applicability of animal-derived disulfide-rich scaffolds to design pathway and subtype selective MC4R pharmacological probes. In the future, this approach could be exploited to develop functionally selective ligands that could offer safer and more effective obesity drugs.
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Affiliation(s)
- Edin Muratspahić
- Center
for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
- Institute
for Molecular Bioscience, Australian Research Council Centre of Excellence
for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Despoina Aslanoglou
- Department
of Endocrinology, Queen Mary University
of London, London E1 4NS, U.K.
| | - Andrew M. White
- Institute
for Molecular Bioscience, Australian Research Council Centre of Excellence
for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Claudia Draxler
- Center
for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Xaver Kozisek
- Center
for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Zara Farooq
- Department
of Endocrinology, Queen Mary University
of London, London E1 4NS, U.K.
| | - David J. Craik
- Institute
for Molecular Bioscience, Australian Research Council Centre of Excellence
for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Peter J. McCormick
- Department
of Endocrinology, Queen Mary University
of London, London E1 4NS, U.K.
| | - Thomas Durek
- Institute
for Molecular Bioscience, Australian Research Council Centre of Excellence
for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Christian W. Gruber
- Center
for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
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3
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Jacob B, Vogelaar A, Cadenas E, Camarero JA. Using the Cyclotide Scaffold for Targeting Biomolecular Interactions in Drug Development. Molecules 2022; 27:molecules27196430. [PMID: 36234971 PMCID: PMC9570680 DOI: 10.3390/molecules27196430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 09/21/2022] [Accepted: 09/24/2022] [Indexed: 11/28/2022] Open
Abstract
This review provides an overview of the properties of cyclotides and their potential for developing novel peptide-based therapeutics. The selective disruption of protein–protein interactions remains challenging, as the interacting surfaces are relatively large and flat. However, highly constrained polypeptide-based molecular frameworks with cell-permeability properties, such as the cyclotide scaffold, have shown great promise for targeting those biomolecular interactions. The use of molecular techniques, such as epitope grafting and molecular evolution employing the cyclotide scaffold, has shown to be highly effective for selecting bioactive cyclotides.
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Affiliation(s)
- Binu Jacob
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 9033, USA
| | - Alicia Vogelaar
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 9033, USA
| | - Enrique Cadenas
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 9033, USA
| | - Julio A. Camarero
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 9033, USA
- Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA 9033, USA
- Correspondence:
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4
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White AM, Dellsén A, Larsson N, Kaas Q, Jansen F, Plowright AT, Knerr L, Durek T, Craik DJ. Late-Stage Functionalization with Cysteine Staples Generates Potent and Selective Melanocortin Receptor-1 Agonists. J Med Chem 2022; 65:12956-12969. [PMID: 36167503 DOI: 10.1021/acs.jmedchem.2c00793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In this work, cysteine staples were used as a late-stage functionalization strategy to diversify peptides and build conjugates targeting the melanocortin G-protein-coupled receptors [melanocortin receptor-1 (MC1R) and MC3R-MC5R]. Monocyclic and bicyclic agonists based on sunflower trypsin inhibitor-1 were used to generate a selection of stapled peptides that were evaluated for binding (pKi) and functional activation (pEC50) of the melanocortin receptor subtypes. Stapled peptides generally had improved activity, with aromatic stapled peptides yielding selective MC1R agonists, including a xylene-stapled peptide (2) with an EC50 of 1.9 nM for MC1R and >150-fold selectivity for MC3R and MC4R. Selected stapled peptides were further functionalized with linkers and payloads, generating a series of conjugated peptides with potent MC1R activity, including one pyridazine-functionalized peptide (21) with picomolar activity at MC1R (Ki 58 pM; EC50 < 9 pM). This work demonstrates that staples can be used as modular synthetic tools to tune potency and selectivity in peptide-based drug design.
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Affiliation(s)
- Andrew M White
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Anita Dellsén
- Mechanistic Biology & Profiling, Discovery Sciences, R&D, AstraZeneca, Gothenburg 43183, Sweden
| | - Niklas Larsson
- Discovery Biology, Discovery Sciences, R&D, AstraZeneca, Gothenburg 43183, Sweden
| | - Quentin Kaas
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Frank Jansen
- Mechanistic Biology & Profiling, Discovery Sciences, R&D, AstraZeneca, Gothenburg 43183, Sweden
| | - Alleyn T Plowright
- Medicinal Chemistry, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg 43183, Sweden
| | - Laurent Knerr
- Medicinal Chemistry, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg 43183, Sweden
| | - Thomas Durek
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - David J Craik
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland 4072, Australia
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5
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Taghizadeh MS, Retzl B, Muratspahić E, Trenk C, Casanova E, Moghadam A, Afsharifar A, Niazi A, Gruber CW. Discovery of the cyclotide caripe 11 as a ligand of the cholecystokinin-2 receptor. Sci Rep 2022; 12:9215. [PMID: 35654807 PMCID: PMC9163038 DOI: 10.1038/s41598-022-13142-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 05/20/2022] [Indexed: 11/08/2022] Open
Abstract
The cholecystokinin-2 receptor (CCK2R) is a G protein-coupled receptor (GPCR) that is expressed in peripheral tissues and the central nervous system and constitutes a promising target for drug development in several diseases, such as gastrointestinal cancer. The search for ligands of this receptor over the past years mainly resulted in the discovery of a set of distinct synthetic small molecule chemicals. Here, we carried out a pharmacological screening of cyclotide-containing plant extracts using HEK293 cells transiently-expressing mouse CCK2R, and inositol phosphate (IP1) production as a readout. Our data demonstrated that cyclotide-enriched plant extracts from Oldenlandia affinis, Viola tricolor and Carapichea ipecacuanha activate the CCK2R as measured by the production of IP1. These findings prompted the isolation of a representative cyclotide, namely caripe 11 from C. ipecacuanha for detailed pharmacological analysis. Caripe 11 is a partial agonist of the CCK2R (Emax = 71%) with a moderate potency of 8.5 µM, in comparison to the endogenous full agonist cholecystokinin-8 (CCK-8; EC50 = 11.5 nM). The partial agonism of caripe 11 is further characterized by an increase on basal activity (at low concentrations) and a dextral-shift of the potency of CCK-8 (at higher concentrations) following its co-incubation with the cyclotide. Therefore, cyclotides such as caripe 11 may be explored in the future for the design and development of cyclotide-based ligands or imaging probes targeting the CCK2R and related peptide GPCRs.
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Affiliation(s)
- Mohammad Sadegh Taghizadeh
- Center for Physiology and Pharmacology, Medical University of Vienna, 1090, Vienna, Austria
- Institute of Biotechnology, Shiraz University, Shiraz, Iran
| | - Bernhard Retzl
- Center for Physiology and Pharmacology, Medical University of Vienna, 1090, Vienna, Austria
| | - Edin Muratspahić
- Center for Physiology and Pharmacology, Medical University of Vienna, 1090, Vienna, Austria
| | - Christoph Trenk
- Center for Physiology and Pharmacology, Medical University of Vienna, 1090, Vienna, Austria
| | - Emilio Casanova
- Center for Physiology and Pharmacology, Medical University of Vienna, 1090, Vienna, Austria
| | - Ali Moghadam
- Institute of Biotechnology, Shiraz University, Shiraz, Iran
| | | | - Ali Niazi
- Institute of Biotechnology, Shiraz University, Shiraz, Iran
| | - Christian W Gruber
- Center for Physiology and Pharmacology, Medical University of Vienna, 1090, Vienna, Austria.
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6
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Gupta S, Azadvari N, Hosseinzadeh P. Design of Protein Segments and Peptides for Binding to Protein Targets. BIODESIGN RESEARCH 2022; 2022:9783197. [PMID: 37850124 PMCID: PMC10521657 DOI: 10.34133/2022/9783197] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 03/16/2022] [Indexed: 10/19/2023] Open
Abstract
Recent years have witnessed a rise in methods for accurate prediction of structure and design of novel functional proteins. Design of functional protein fragments and peptides occupy a small, albeit unique, space within the general field of protein design. While the smaller size of these peptides allows for more exhaustive computational methods, flexibility in their structure and sparsity of data compared to proteins, as well as presence of noncanonical building blocks, add additional challenges to their design. This review summarizes the current advances in the design of protein fragments and peptides for binding to targets and discusses the challenges in the field, with an eye toward future directions.
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Affiliation(s)
- Suchetana Gupta
- Knight Campus Center for Accelerating Scientific Impact, University of Oregon, Eugene OR 97403, USA
| | - Noora Azadvari
- Knight Campus Center for Accelerating Scientific Impact, University of Oregon, Eugene OR 97403, USA
| | - Parisa Hosseinzadeh
- Knight Campus Center for Accelerating Scientific Impact, University of Oregon, Eugene OR 97403, USA
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7
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Farooq Z, Howell LA, McCormick PJ. Probing GPCR Dimerization Using Peptides. Front Endocrinol (Lausanne) 2022; 13:843770. [PMID: 35909575 PMCID: PMC9329873 DOI: 10.3389/fendo.2022.843770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Accepted: 06/10/2022] [Indexed: 11/13/2022] Open
Abstract
G protein-coupled receptors (GPCRs) are the largest class of membrane proteins and the most common and extensively studied pharmacological target. Numerous studies over the last decade have confirmed that GPCRs do not only exist and function in their monomeric form but in fact, have the ability to form dimers or higher order oligomers with other GPCRs, as well as other classes of receptors. GPCR oligomers have become increasingly attractive to investigate as they have the ability to modulate the pharmacological responses of the receptors which in turn, could have important functional roles in diseases, such as cancer and several neurological & neuropsychiatric disorders. Despite the growing evidence in the field of GPCR oligomerisation, the lack of structural information, as well as targeting the 'undruggable' protein-protein interactions (PPIs) involved in these complexes, has presented difficulties. Outside the field of GPCRs, targeting PPIs has been widely studied, with a variety of techniques being investigated; from small-molecule inhibitors to disrupting peptides. In this review, we will demonstrate several physiologically relevant GPCR dimers and discuss an array of strategies and techniques that can be employed when targeting these complexes, as well as provide ideas for future development.
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Affiliation(s)
- Zara Farooq
- Centre for Endocrinology, William Harvey Research Institute, Bart’s and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London, United Kingdom
- Department of Chemistry, School of Physical and Chemical Sciences, Queen Mary University of London, Mile End Road, London, United Kingdom
| | - Lesley A. Howell
- Department of Chemistry, School of Physical and Chemical Sciences, Queen Mary University of London, Mile End Road, London, United Kingdom
| | - Peter J. McCormick
- Centre for Endocrinology, William Harvey Research Institute, Bart’s and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London, United Kingdom
- *Correspondence: Peter J. McCormick,
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8
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Dahal A, Sonju JJ, Kousoulas KG, Jois SD. Peptides and peptidomimetics as therapeutic agents for Covid-19. Pept Sci (Hoboken) 2022; 114:e24245. [PMID: 34901700 PMCID: PMC8646791 DOI: 10.1002/pep2.24245] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 08/24/2021] [Accepted: 08/26/2021] [Indexed: 12/27/2022]
Abstract
The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) Covid-19 pandemic has caused high morbidity and mortality rates worldwide. Virus entry into cells can be blocked using several strategies, including inhibition of protein-protein interactions (PPIs) between the viral spike glycoprotein and cellular receptors, as well as blocking of spike protein conformational changes that are required for cleavage/activation and fusogenicity. The spike-mediated viral attachment and entry into cells via fusion of the viral envelope with cellular membranes involve PPIs mediated by short peptide fragments exhibiting particular secondary structures. Thus, peptides that can inhibit these PPIs may be used as potential antiviral agents preventing virus entry and spread. This review is focused on peptides and peptidomimetics as PPI modulators and protease inhibitors against SARS-CoV-2.
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Affiliation(s)
- Achyut Dahal
- School of Basic Pharmaceutical and Toxicological Sciences, College of PharmacyUniversity of Louisiana at MonroeMonroeLouisianaUSA
| | - Jafrin Jobayer Sonju
- School of Basic Pharmaceutical and Toxicological Sciences, College of PharmacyUniversity of Louisiana at MonroeMonroeLouisianaUSA
| | - Konstantin G. Kousoulas
- Department of Pathobiological Sciences, School of Veterinary MedicineLouisiana State UniversityBaton RougeLouisianaUSA
| | - Seetharama D. Jois
- School of Basic Pharmaceutical and Toxicological Sciences, College of PharmacyUniversity of Louisiana at MonroeMonroeLouisianaUSA
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9
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Hellinger R, Muratspahić E, Devi S, Koehbach J, Vasileva M, Harvey PJ, Craik DJ, Gründemann C, Gruber CW. Importance of the Cyclic Cystine Knot Structural Motif for Immunosuppressive Effects of Cyclotides. ACS Chem Biol 2021; 16:2373-2386. [PMID: 34592097 PMCID: PMC9286316 DOI: 10.1021/acschembio.1c00524] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The cyclotide T20K inhibits the proliferation of human immune cells and is currently in clinical trials for multiple sclerosis. Here, we provide novel functional data and mechanistic insights into structure-activity relationships of T20K. Analogs with partial or complete reduction of the cystine knot had loss of function in proliferation experiments. Similarly, an acyclic analog of T20K was inactive in lymphocyte bioassays. The lack of activity of non-native peptide analogs appears to be associated with the ability of cyclotides to interact with and penetrate cell membranes, since cellular uptake studies demonstrated fast fractional transfer only of the native peptide into the cytosol of human immune cells. Therefore, structural differences between cyclic and linear native folded peptides were investigated by NMR to elucidate structure-activity relationships. Acyclic T20K had a less rigid backbone and considerable structural changes in loops 1 and 6 compared to the native cyclic T20K, supporting the idea that the cyclic cystine knot motif is a unique bioactive scaffold. This study provides evidence that this structural motif in cyclotides governs bioactivity, interactions with and transport across biological membranes, and the structural integrity of these peptides. These observations could be useful to understand the structure-activity of other cystine knot proteins due to the structural conservation of the cystine knot motif across evolution and to provide guidance for the design of novel cyclic cysteine-stabilized molecules.
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Affiliation(s)
- Roland Hellinger
- Center for
Physiology and Pharmacology, Medical University
of Vienna, Schwarzspanierstr. 17, Vienna 1090, Austria
| | - Edin Muratspahić
- Center for
Physiology and Pharmacology, Medical University
of Vienna, Schwarzspanierstr. 17, Vienna 1090, Austria
| | - Seema Devi
- Institute
for Infection Prevention and Hospital Epidemiology, Center for Complementary
Medicine, Faculty of Medicine, University
of Freiburg, Breisacher Str. 115B, Freiburg 79106, Germany
| | - Johannes Koehbach
- Institute
for Molecular Bioscience, Australian Research Council Centre of Excellence
for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Mina Vasileva
- Center for
Physiology and Pharmacology, Medical University
of Vienna, Schwarzspanierstr. 17, Vienna 1090, Austria
| | - Peta J. Harvey
- Institute
for Molecular Bioscience, Australian Research Council Centre of Excellence
for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - David J. Craik
- Institute
for Molecular Bioscience, Australian Research Council Centre of Excellence
for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Carsten Gründemann
- Translational
Complementary Medicine, Department of Pharmaceutical Sciences, University of Basel, Klingelbergstr. 80, Basel 4056, Switzerland
| | - Christian W. Gruber
- Center for
Physiology and Pharmacology, Medical University
of Vienna, Schwarzspanierstr. 17, Vienna 1090, Austria
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10
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Muratspahić E, Tomašević N, Nasrollahi-Shirazi S, Gattringer J, Emser FS, Freissmuth M, Gruber CW. Plant-Derived Cyclotides Modulate κ-Opioid Receptor Signaling. JOURNAL OF NATURAL PRODUCTS 2021; 84:2238-2248. [PMID: 34308635 PMCID: PMC8406418 DOI: 10.1021/acs.jnatprod.1c00301] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Indexed: 05/03/2023]
Abstract
Cyclotides are plant-derived disulfide-rich peptides comprising a cyclic cystine knot, which confers remarkable stability against thermal, proteolytic, and chemical degradation. They represent an emerging class of G protein-coupled receptor (GPCR) ligands. In this study, utilizing a screening approach of plant extracts and pharmacological analysis we identified cyclotides from Carapichea ipecacuanha to be ligands of the κ-opioid receptor (KOR), an attractive target for developing analgesics with reduced side effects and therapeutics for multiple sclerosis (MS). This prompted us to verify whether [T20K]kalata B1, a cyclotide in clinical development for the treatment of MS, is able to modulate KOR signaling. T20K bound to and fully activated KOR in the low μM range. We then explored the ability of T20K to allosterically modulate KOR. Co-incubation of T20K with KOR ligands resulted in positive allosteric modulation in functional cAMP assays by altering either the efficacy of dynorphin A1-13 or the potency and efficacy of U50,488 (a selective KOR agonist), respectively. In addition, T20K increased the basal response upon cotreatment with U50,488. In the bioluminescence resonance energy transfer assay T20K negatively modulated the efficacy of U50,488. This study identifies cyclotides capable of modulating KOR and highlights the potential of plant-derived peptides as an opportunity to develop cyclotide-based KOR modulators.
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Affiliation(s)
- Edin Muratspahić
- Center
for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Nataša Tomašević
- Center
for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Shahrooz Nasrollahi-Shirazi
- Center
for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
- Gaston
H. Glock Research Laboratories for Exploratory Drug Development, Center
for Physiology and Pharmacology, Medical
University of Vienna, 1090 Vienna, Austria
| | - Jasmin Gattringer
- Center
for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Fabiola Susanna Emser
- Center
for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Michael Freissmuth
- Center
for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
- Gaston
H. Glock Research Laboratories for Exploratory Drug Development, Center
for Physiology and Pharmacology, Medical
University of Vienna, 1090 Vienna, Austria
| | - Christian W. Gruber
- Center
for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
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11
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Muratspahić E, Tomašević N, Koehbach J, Duerrauer L, Hadžić S, Castro J, Schober G, Sideromenos S, Clark RJ, Brierley SM, Craik DJ, Gruber CW. Design of a Stable Cyclic Peptide Analgesic Derived from Sunflower Seeds that Targets the κ-Opioid Receptor for the Treatment of Chronic Abdominal Pain. J Med Chem 2021; 64:9042-9055. [PMID: 34162205 PMCID: PMC8273886 DOI: 10.1021/acs.jmedchem.1c00158] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Indexed: 02/01/2023]
Abstract
The rising opioid crisis has become a worldwide societal and public health burden, resulting from the abuse of prescription opioids. Targeting the κ-opioid receptor (KOR) in the periphery has emerged as a powerful approach to develop novel pain medications without central side effects. Inspired by the traditional use of sunflower (Helianthus annuus) preparations for analgesic purposes, we developed novel stabilized KOR ligands (termed as helianorphins) by incorporating different dynorphin A sequence fragments into a cyclic sunflower peptide scaffold. As a result, helianorphin-19 selectively bound to and fully activated the KOR with nanomolar potency. Importantly, helianorphin-19 exhibited strong KOR-specific peripheral analgesic activity in a mouse model of chronic visceral pain, without inducing unwanted central effects on motor coordination/sedation. Our study provides a proof of principle that cyclic peptides from plants may be used as templates to develop potent and stable peptide analgesics applicable via enteric administration by targeting the peripheral KOR for the treatment of chronic abdominal pain.
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MESH Headings
- Abdominal Pain/drug therapy
- Analgesics/chemical synthesis
- Analgesics/chemistry
- Analgesics/pharmacology
- Animals
- Cells, Cultured
- Chronic Disease
- Dose-Response Relationship, Drug
- Drug Design
- HEK293 Cells
- Helianthus/chemistry
- Humans
- Male
- Mice
- Mice, Inbred C57BL
- Molecular Structure
- Peptides, Cyclic/chemical synthesis
- Peptides, Cyclic/chemistry
- Peptides, Cyclic/pharmacology
- Plant Extracts/chemical synthesis
- Plant Extracts/chemistry
- Plant Extracts/pharmacology
- Receptors, Opioid, kappa/antagonists & inhibitors
- Receptors, Opioid, kappa/metabolism
- Seeds/chemistry
- Structure-Activity Relationship
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Affiliation(s)
- Edin Muratspahić
- Center
for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Nataša Tomašević
- Center
for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Johannes Koehbach
- Institute
for Molecular Bioscience, Australian Research Council Centre of Excellence
for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Leopold Duerrauer
- Center
for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
- School
of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Seid Hadžić
- Center
for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Joel Castro
- Visceral
Pain Research Group, College of Medicine and Public Health, Flinders
Health and Medical Research Institute (FHMRI), Flinders University, Bedford
Park, South Australia 5042, Australia
- Hopwood
Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), North Terrace, Adelaide, South Australia 5000, Australia
| | - Gudrun Schober
- Visceral
Pain Research Group, College of Medicine and Public Health, Flinders
Health and Medical Research Institute (FHMRI), Flinders University, Bedford
Park, South Australia 5042, Australia
- Hopwood
Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), North Terrace, Adelaide, South Australia 5000, Australia
| | - Spyridon Sideromenos
- Center for
Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Richard J. Clark
- School
of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Stuart M. Brierley
- Visceral
Pain Research Group, College of Medicine and Public Health, Flinders
Health and Medical Research Institute (FHMRI), Flinders University, Bedford
Park, South Australia 5042, Australia
- Hopwood
Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), North Terrace, Adelaide, South Australia 5000, Australia
- Discipline
of Medicine, University of Adelaide, North Terrace, Adelaide, South Australia 5000, Australia
| | - David J. Craik
- Institute
for Molecular Bioscience, Australian Research Council Centre of Excellence
for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Christian W. Gruber
- Center
for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
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12
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Grover T, Mishra R, Gulati P, Mohanty A. An insight into biological activities of native cyclotides for potential applications in agriculture and pharmaceutics. Peptides 2021; 135:170430. [PMID: 33096195 DOI: 10.1016/j.peptides.2020.170430] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 10/06/2020] [Accepted: 10/12/2020] [Indexed: 02/08/2023]
Abstract
Cyclotides are plant-derived mini-proteins of 28 - 37 amino acids. They have a characteristic head-to-tail cyclic backbone and three disulfide cross-linkages formed by six highly conserved cysteine residues, creating a unique knotted ring structure, known as a cyclic cystine knot (CCK) motif. The CCK topology confers immense stability to cyclotides with resistance to thermal and enzymatic degradation. Native cyclotides are of interest due to their multiple biological activities with several potential applications in agricultural (e.g. biopesticides, antifungal) and pharmaceutical (e.g. anti-HIV, cytotoxic to tumor cells) sectors. The most recent application of insecticidal activity of cyclotides is the commercially available biopesticidal spray known as 'Sero X' for cotton crops. Cyclotides have a general mode of action and their potency of bioactivity is determined through their binding ability, pore formation and disruption of the target biological membranes. Keeping in view the important potential applications of biological activities of cyclotides and the lack of an extensive and analytical compilation of bioactive cyclotides, the present review systematically describes eight major biological activities of the native cyclotides from four angiosperm families viz. Fabaceae, Poaceae, Rubiaceae, Violaceae. The bioactivities of 94 cytotoxic, 57 antibacterial, 44 hemolytic, 25 antifungal, 21 anti-HIV, 20 nematocidal, 10 insecticidal and 5 molluscicidal cyclotides have been comprehensively elaborated. Further, their distribution in angiosperm families, mode of action and future prospects have also been discussed.
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Affiliation(s)
- Tripti Grover
- Bioinformatics Infrastructure Facility, Gargi College, University of Delhi, India
| | - Reema Mishra
- Department of Botany, Gargi College, University of Delhi, India
| | - Pooja Gulati
- Department of Microbiology, Maharshi Dayanand University, Rohtak, Haryana, India
| | - Aparajita Mohanty
- Bioinformatics Infrastructure Facility, Gargi College, University of Delhi, India.
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13
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González-Castro R, Gómez-Lim MA, Plisson F. Cysteine-Rich Peptides: Hyperstable Scaffolds for Protein Engineering. Chembiochem 2020; 22:961-973. [PMID: 33095969 DOI: 10.1002/cbic.202000634] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 10/21/2020] [Indexed: 12/14/2022]
Abstract
Cysteine-rich peptides (CRPs) are small proteins of less than 100 amino acids in length characterized by the presence of disulfide bridges and common end-to-end macrocyclization. These properties confer hyperstability against high temperatures, salt concentration, serum presence, and protease degradation to CRPs. Moreover, their intercysteine domains (loops) are susceptible to residue hypervariability. CRPs have been successfully applied as stable scaffolds for molecular grafting, a protein engineering process in which cysteine-rich structures provide higher thermodynamic and metabolic stability to an epitope and acquire new biological function(s). This review describes the successes and limitations of seven cysteine-rich scaffolds, their bioactive epitopes, and the resulting grafted peptides.
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Affiliation(s)
- Rafael González-Castro
- Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV) Unidad de Genómica Avanzada, Laboratorio Nacional de Genómica para la Biodiversidad (Langebio), Irapuato, Guanajuato, 36824, México.,Centro de Investigación y de Estudios Avanzados del IPN Unidad Irapuato, Departamento de Ingeniería Genética, Irapuato, Guanajuato, 36824, México
| | - Miguel A Gómez-Lim
- Centro de Investigación y de Estudios Avanzados del IPN Unidad Irapuato, Departamento de Ingeniería Genética, Irapuato, Guanajuato, 36824, México
| | - Fabien Plisson
- CONACYT, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV) Unidad de Genómica Avanzada, Laboratorio Nacional de Genómica para la Biodiversidad (Langebio), Irapuato, Guanajuato, 36824, México
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14
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Qu H, Jackson MA, Yap K, Harvey PJ, Gilding EK, Craik DJ. Production of a structurally validated cyclotide in rice suspension cells is enabled by a supporting biosynthetic enzyme. PLANTA 2020; 252:97. [PMID: 33155076 DOI: 10.1007/s00425-020-03505-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 10/26/2020] [Indexed: 05/22/2023]
Abstract
We demonstrate the production of a structurally correct cyclotide in rice suspension cells with co-expression of a ligase-type AEP, which unlocks monocotyledons as production platforms to produce cyclotides. Cyclotides are a class of backbone-cyclic plant peptides that harbor a cystine knot composed of three disulfide bonds. These structural features make cyclotides particularly stable, and thus they have attracted significant attention for their use in biotechnological applications such as drug design. Currently, chemical synthesis is the predominant strategy to produce cyclotides for research purposes. However, synthetic production becomes costly both economically and environmentally at large scale. Plants offer an attractive alternative to chemical synthesis because of their lower cost and environmental footprint. In this study, rice suspension cells were engineered to produce the prototypical cyclotide, kalata B1 (kB1), a cyclotide with insecticidal properties from the African plant Oldenlandia affinis. Engineered rice cells produced structurally validated kB1 at yields of 64.21 µg/g (DW), which was dependent on the co-expression of a peptide ligase-competent asparaginyl endopeptidase OaAEP1b from O. affinis. Without co-expression, kB1 was predominantly produced as linear peptide. Through HPLC-MS co-elution, reduction, alkylation, enzymatic digestion, and proton NMR analysis, kB1 produced in rice was shown to be structurally identical to native kB1. This study reports the first example of an engineered plant suspension cell culture with the required molecular machinery for efficient production and cyclisation of a heterologous cyclotide.
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Affiliation(s)
- Haiou Qu
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Mark A Jackson
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Kuok Yap
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Peta J Harvey
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Edward K Gilding
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - David J Craik
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, QLD, 4072, Australia.
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15
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Malik U, Chan LY, Cai M, Hruby VJ, Kaas Q, Daly NL, Craik DJ. Development of novel frog‐skin peptide scaffolds with selectivity towards melanocortin receptor subtypes. Pept Sci (Hoboken) 2020. [DOI: 10.1002/pep2.24209] [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)
- Uru Malik
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science The University of Queensland Brisbane Queensland Australia
| | - Lai Yue Chan
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science The University of Queensland Brisbane Queensland Australia
| | - Minying Cai
- Department of Chemistry and Biochemistry University of Arizona Tucson Arizona USA
| | - Victor J. Hruby
- Department of Chemistry and Biochemistry University of Arizona Tucson Arizona USA
| | - Quentin Kaas
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science The University of Queensland Brisbane Queensland Australia
| | - Norelle L. Daly
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science The University of Queensland Brisbane Queensland Australia
- Australian Institute of Tropical Health and Medicine James Cook University Cairns Queensland Australia
| | - David J. Craik
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science The University of Queensland Brisbane Queensland Australia
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16
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Handley TNG, Wang CK, Harvey PJ, Lawrence N, Craik DJ. Cyclotide Structures Revealed by NMR, with a Little Help from X‐ray Crystallography. Chembiochem 2020; 21:3463-3475. [DOI: 10.1002/cbic.202000315] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 07/08/2020] [Indexed: 12/12/2022]
Affiliation(s)
- Thomas N. G. Handley
- Institute for Molecular Bioscience Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science The University of Queensland Brisbane Queensland 4072 Australia
| | - Conan K. Wang
- Institute for Molecular Bioscience Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science The University of Queensland Brisbane Queensland 4072 Australia
| | - Peta J. Harvey
- Institute for Molecular Bioscience Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science The University of Queensland Brisbane Queensland 4072 Australia
| | - Nicole Lawrence
- Institute for Molecular Bioscience Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science The University of Queensland Brisbane Queensland 4072 Australia
| | - David J. Craik
- Institute for Molecular Bioscience Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science The University of Queensland Brisbane Queensland 4072 Australia
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17
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Muratspahić E, Koehbach J, Gruber CW, Craik DJ. Harnessing cyclotides to design and develop novel peptide GPCR ligands. RSC Chem Biol 2020; 1:177-191. [PMID: 34458757 PMCID: PMC8341132 DOI: 10.1039/d0cb00062k] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 07/10/2020] [Indexed: 12/13/2022] Open
Abstract
Cyclotides are plant-derived cyclic, disulfide-rich peptides with a unique cyclic cystine knot topology that confers them with remarkable structural stability and resistance to proteolytic degradation. Recently, cyclotides have emerged as promising scaffold molecules for designing peptide-based therapeutics. Here, we provide examples of how engineering cyclotides using molecular grafting may lead to the development of novel peptide ligands of G protein-coupled receptors (GPCRs), today's most exploited drug targets. Integrating bioactive epitopes into stable cyclotide scaffolds can lead to improved pharmacokinetics and oral activity as well as selectivity and high enzymatic stability. We also discuss and highlight the importance of engineered cyclotides as novel tools to study GPCR signaling.
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Affiliation(s)
- Edin Muratspahić
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna Austria
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland Brisbane Queensland 4072 Australia
| | - Johannes Koehbach
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland Brisbane Queensland 4072 Australia
| | - Christian W Gruber
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna Austria
| | - David J Craik
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland Brisbane Queensland 4072 Australia
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18
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Crook ZR, Nairn NW, Olson JM. Miniproteins as a Powerful Modality in Drug Development. Trends Biochem Sci 2020; 45:332-346. [PMID: 32014389 PMCID: PMC7197703 DOI: 10.1016/j.tibs.2019.12.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 12/06/2019] [Accepted: 12/31/2019] [Indexed: 01/03/2023]
Abstract
Miniproteins are a diverse group of protein scaffolds characterized by small (1-10 kDa) size, stability, and versatility in drug-like roles. Coming largely from native sources, they have been widely adopted into drug development pipelines. While their structures and capabilities are diverse, the approaches to their utilization share more similarities with each other than with more widely used modalities (e.g., antibodies or small molecules). In this review, we highlight recent advances in miniprotein-based approaches to otherwise poorly addressed clinical needs, including structure-based and functional characterization. We also summarize their unique screening strategies and pharmacology considerations. Through a greater understanding of the unique properties that make them attractive for drug design, miniproteins can be effectively utilized against targets that are intractable by other approaches.
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Affiliation(s)
- Zachary R Crook
- Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N., Room D4-100, Seattle, WA 98109, USA
| | - Natalie W Nairn
- Blaze Bioscience, Inc, 530 Fairview Ave N., Suite 1400, Seattle, WA 98109, USA
| | - James M Olson
- Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N., Room D4-100, Seattle, WA 98109, USA.
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19
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Abstract
This Review explores the class of plant-derived macrocyclic peptides called cyclotides. We include an account of their discovery, characterization, and distribution in the plant kingdom as well as a detailed analysis of their sequences and structures, biosynthesis and chemical synthesis, biological functions, and applications. These macrocyclic peptides are around 30 amino acids in size and are characterized by their head-to-tail cyclic backbone and cystine knot motif, which render them to be exceptionally stable, with resistance to thermal or enzymatic degradation. Routes to their chemical synthesis have been developed over the past two decades, and this capability has facilitated a wide range of mutagenesis and structure-activity relationship studies. In turn, these studies have both led to an increased understanding of their mechanisms of action as well as facilitated a range of applications in agriculture and medicine, as ecofriendly crop protection agents, and as drug leads or scaffolds for pharmaceutical design. Our overall objective in this Review is to provide readers with a comprehensive overview of cyclotides that we hope will stimulate further work on this fascinating family of peptides.
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Affiliation(s)
- Simon J de Veer
- Institute for Molecular Bioscience , The University of Queensland , Brisbane , Queensland 4072 , Australia
| | - Meng-Wei Kan
- Institute for Molecular Bioscience , The University of Queensland , Brisbane , Queensland 4072 , Australia
| | - David J Craik
- Institute for Molecular Bioscience , The University of Queensland , Brisbane , Queensland 4072 , Australia
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20
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Yathursan S, Wiles S, Read H, Sarojini V. A review on anti-tuberculosis peptides: Impact of peptide structure on anti-tuberculosis activity. J Pept Sci 2019; 25:e3213. [PMID: 31515916 DOI: 10.1002/psc.3213] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 08/03/2019] [Accepted: 08/07/2019] [Indexed: 12/18/2022]
Abstract
Antibiotic resistance is a major public health problem globally. Particularly concerning amongst drug-resistant human pathogens is Mycobacterium tuberculosis that causes the deadly infectious tuberculosis (TB) disease. Significant issues associated with current treatment options for drug-resistant TB and the high rate of mortality from the disease makes the development of novel treatment options against this pathogen an urgent need. Antimicrobial peptides are part of innate immunity in all forms of life and could provide a potential solution against drug-resistant TB. This review is a critical analysis of antimicrobial peptides that are reported to be active against the M tuberculosis complex exclusively. However, activity on non-TB strains such as Mycobacterium avium and Mycobacterium intracellulare, whenever available, have been included at appropriate sections for these anti-TB peptides. Natural and synthetic antimicrobial peptides of diverse sequences, along with their chemical structures, are presented, discussed, and correlated to their observed antimycobacterial activities. Critical analyses of the structure allied to the anti-mycobacterial activity have allowed us to draw important conclusions and ideas for research and development on these promising molecules to realise their full potential. Even though the review is focussed on peptides, we have briefly summarised the structures and potency of the various small molecule drugs that are available and under development, for TB treatment.
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Affiliation(s)
- Sutharsana Yathursan
- School of Chemical Sciences, University of Auckland, Private Bag, 92019, Auckland, New Zealand
| | - Siouxsie Wiles
- Bioluminescent Superbugs Lab, Department of Molecular Medicine and Pathology, University of Auckland, Private Bag, 92019, Auckland, New Zealand
| | - Hannah Read
- Bioluminescent Superbugs Lab, Department of Molecular Medicine and Pathology, University of Auckland, Private Bag, 92019, Auckland, New Zealand
| | - Vijayalekshmi Sarojini
- School of Chemical Sciences, University of Auckland, Private Bag, 92019, Auckland, New Zealand.,The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, 6140, New Zealand
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21
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Poth AG, Huang YH, Le TT, Kan MW, Craik DJ. Pharmacokinetic characterization of kalata B1 and related therapeutics built on the cyclotide scaffold. Int J Pharm 2019; 565:437-446. [DOI: 10.1016/j.ijpharm.2019.05.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/24/2019] [Accepted: 05/03/2019] [Indexed: 02/08/2023]
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22
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Camarero JA, Campbell MJ. The Potential of the Cyclotide Scaffold for Drug Development. Biomedicines 2019; 7:biomedicines7020031. [PMID: 31010257 PMCID: PMC6631875 DOI: 10.3390/biomedicines7020031] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Revised: 04/13/2019] [Accepted: 04/15/2019] [Indexed: 12/11/2022] Open
Abstract
Cyclotides are a novel class of micro-proteins (≈30-40 residues long) with a unique topology containing a head-to-tail cyclized backbone structure further stabilized by three disulfide bonds that form a cystine knot. This unique molecular framework makes them exceptionally stable to physical, chemical, and biological degradation compared to linear peptides of similar size. The cyclotides are also highly tolerant to sequence variability, aside from the conserved residues forming the cystine knot, and are orally bioavailable and able to cross cellular membranes to modulate intracellular protein-protein interactions (PPIs), both in vitro and in vivo. These unique properties make them ideal scaffolds for many biotechnological applications, including drug discovery. This review provides an overview of the properties of cyclotides and their potential for the development of novel peptide-based therapeutics. The selective disruption of PPIs still remains a very challenging task, as the interacting surfaces are relatively large and flat. The use of the cell-permeable highly constrained polypeptide molecular frameworks, such as the cyclotide scaffold, has shown great promise, as it provides unique pharmacological properties. The use of molecular techniques, such as epitope grafting, and molecular evolution have shown to be highly effective for the selection of bioactive cyclotides. However, despite successes in employing cyclotides to target PPIs, some of the challenges to move them into the clinic still remain.
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Affiliation(s)
- Julio A Camarero
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 9033, USA.
- Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, Los Angeles, CA 9033, USA.
| | - Maria Jose Campbell
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 9033, USA.
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23
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Muratspahić E, Freissmuth M, Gruber CW. Nature-Derived Peptides: A Growing Niche for GPCR Ligand Discovery. Trends Pharmacol Sci 2019; 40:309-326. [PMID: 30955896 DOI: 10.1016/j.tips.2019.03.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 02/26/2019] [Accepted: 03/06/2019] [Indexed: 12/11/2022]
Abstract
G protein-coupled receptors (GPCRs) represent important drug targets, as they regulate pivotal physiological processes and they have proved to be readily druggable. Natural products have been and continue to be amongst the most valuable sources for drug discovery and development. Here, we surveyed small molecules and (poly-)peptides derived from plants, animals, fungi, and bacteria, which modulate GPCR signaling. Among naturally occurring compounds, peptides from plants, cone-snails, snakes, spiders, scorpions, fungi, and bacteria are of particular interest as lead compounds for the development of GPCR ligands, since they cover a chemical space, which differs from that of synthetic small molecules. Peptides, however, face challenges, some of which can be overcome by studying plant-derived compounds. We argue here that the opportunities outweigh the challenges.
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Affiliation(s)
- Edin Muratspahić
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Austria
| | - Michael Freissmuth
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Austria; Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center for Physiology and Pharmacology, Medical University of Vienna, Austria
| | - Christian W Gruber
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Austria.
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24
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Using backbone-cyclized Cys-rich polypeptides as molecular scaffolds to target protein-protein interactions. Biochem J 2019; 476:67-83. [PMID: 30635453 DOI: 10.1042/bcj20180792] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 12/07/2018] [Accepted: 12/11/2018] [Indexed: 12/23/2022]
Abstract
The use of disulfide-rich backbone-cyclized polypeptides, as molecular scaffolds to design a new generation of bioimaging tools and drugs that are potent and specific, and thus might have fewer side effects than traditional small-molecule drugs, is gaining increasing interest among the scientific and in the pharmaceutical industries. Highly constrained macrocyclic polypeptides are exceptionally more stable to chemical, thermal and biological degradation and show better biological activity when compared with their linear counterparts. Many of these relatively new scaffolds have been also found to be highly tolerant to sequence variability, aside from the conserved residues forming the disulfide bonds, able to cross cellular membranes and modulate intracellular protein-protein interactions both in vitro and in vivo These properties make them ideal tools for many biotechnological applications. The present study provides an overview of the new developments on the use of several disulfide-rich backbone-cyclized polypeptides, including cyclotides, θ-defensins and sunflower trypsin inhibitor peptides, in the development of novel bioimaging reagents and therapeutic leads.
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25
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Blanco MJ. Building upon Nature's Framework: Overview of Key Strategies Toward Increasing Drug-Like Properties of Natural Product Cyclopeptides and Macrocycles. Methods Mol Biol 2019; 2001:203-233. [PMID: 31134573 DOI: 10.1007/978-1-4939-9504-2_10] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The pharmaceutical industry has focused mainly in the development of small-molecule entities intended for oral administration for the past decades. As a result, the majority of existing drugs address only a narrow range of biological targets. In the era of post-genomics, transcriptomics, and proteomics, there is an increasing interest on larger modulators of proteins that can span larger surfaces, access new therapeutic mechanisms of action, and provide greater target specificity. Traditional drug-like molecules developed using "rule-of-five" (Ro5) guidelines have been proven ineffective against a variety of challenging targets, such as protein-protein interactions, nucleic acid complexes, and antibacterial modalities. However, natural products are known to be effective at modulating such targets, leading to a renewed focus by medicinal chemists on investigating underrepresented chemical scaffolds associated with natural products. Here we describe recent efforts toward identification of novel natural cyclopeptides and macrocycles as well as selected medicinal chemistry strategies to increase drug-like properties or further exploration of their activity.
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26
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Gunasekera S, Fernandes-Cerqueira C, Wennmalm S, Wähämaa H, Sommarin Y, Catrina AI, Jakobsson PJ, Göransson U. Stabilized Cyclic Peptides as Scavengers of Autoantibodies: Neutralization of Anticitrullinated Protein/Peptide Antibodies in Rheumatoid Arthritis. ACS Chem Biol 2018; 13:1525-1535. [PMID: 29630823 DOI: 10.1021/acschembio.8b00118] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The occurrence of autoantibodies is a hallmark of rheumatoid arthritis, specifically those autoantibodies targeting proteins containing the arginine-derived amino acid citrulline. There is strong evidence showing that the occurrence of anticitrullinated protein/peptide antibodies (ACPA) are involved in disease progression, and ACPA was recently shown to induce pain in animals. Here, we explore a novel concept useful for research, diagnostics, and possibly therapy of autoimmune diseases, namely, to directly target and neutralize autoantibodies using peptide binders. A high-affinity peptide-based scavenger of ACPA was developed by grafting a citrullinated epitope derived from human fibrinogen into a naturally occurring stable peptide scaffold. The best scavenger comprises the truncated epitope α-fibrinogen, [Cit573]fib(566-580), grafted into the scaffold sunflower trypsin inhibitor-1, SFTI-1. The final peptide demonstrates low nanomolar apparent affinity and superior stability.
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Affiliation(s)
- Sunithi Gunasekera
- Division of Pharmacognosy, Department of Medicinal Chemistry, Uppsala University, Biomedical Centre, Box 574, SE-75123 Uppsala, Sweden
| | - Cátia Fernandes-Cerqueira
- Rheumatology Unit, Department of Medicine—Solna, Karolinska Institutet, Karolinska University Hospital, Rheumatology Clinic D2:01, 171 76 Solna, Stockholm, Sweden
| | - Stefan Wennmalm
- Royal Institute of Technology-KTH, Applied Physics, Experimental Biomolecular Physics, Scilifelab, Tomtebodavägen 23, 171 65 Solna, Stockholm, Sweden
| | - Heidi Wähämaa
- Rheumatology Unit, Department of Medicine—Solna, Karolinska Institutet, Karolinska University Hospital, Rheumatology Clinic D2:01, 171 76 Solna, Stockholm, Sweden
| | | | - Anca I. Catrina
- Rheumatology Unit, Department of Medicine—Solna, Karolinska Institutet, Karolinska University Hospital, Rheumatology Clinic D2:01, 171 76 Solna, Stockholm, Sweden
| | - Per-Johan Jakobsson
- Rheumatology Unit, Department of Medicine—Solna, Karolinska Institutet, Karolinska University Hospital, Rheumatology Clinic D2:01, 171 76 Solna, Stockholm, Sweden
| | - Ulf Göransson
- Division of Pharmacognosy, Department of Medicinal Chemistry, Uppsala University, Biomedical Centre, Box 574, SE-75123 Uppsala, Sweden
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27
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Valeur E, Jimonet P. New Modalities, Technologies, and Partnerships in Probe and Lead Generation: Enabling a Mode-of-Action Centric Paradigm. J Med Chem 2018; 61:9004-9029. [DOI: 10.1021/acs.jmedchem.8b00378] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Eric Valeur
- Medicinal Chemistry, Cardiovascular, Renal and Metabolism, IMED Biotech Unit, AstraZeneca, Pepparedsleden 1, Mölndal 431 83, Sweden
| | - Patrick Jimonet
- External Innovation Drug Discovery, Global Business Development & Licensing, Sanofi, 13 quai Jules Guesde, 94400 Vitry-sur-Seine, France
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28
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Designing macrocyclic disulfide-rich peptides for biotechnological applications. Nat Chem Biol 2018; 14:417-427. [DOI: 10.1038/s41589-018-0039-y] [Citation(s) in RCA: 131] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 12/18/2017] [Indexed: 12/21/2022]
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29
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Durek T, Cromm PM, White AM, Schroeder CI, Kaas Q, Weidmann J, Ahmad Fuaad A, Cheneval O, Harvey PJ, Daly NL, Zhou Y, Dellsén A, Österlund T, Larsson N, Knerr L, Bauer U, Kessler H, Cai M, Hruby VJ, Plowright AT, Craik DJ. Development of Novel Melanocortin Receptor Agonists Based on the Cyclic Peptide Framework of Sunflower Trypsin Inhibitor-1. J Med Chem 2018; 61:3674-3684. [PMID: 29605997 DOI: 10.1021/acs.jmedchem.8b00170] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Ultrastable cyclic peptide frameworks offer great potential for drug design due to their improved bioavailability compared to their linear analogues. Using the sunflower trypsin inhibitor-1 (SFTI-1) peptide scaffold in combination with systematic N-methylation of the grafted pharmacophore led to the identification of novel subtype selective melanocortin receptor (MCR) agonists. Multiple bicyclic peptides were synthesized and tested toward their activity at MC1R and MC3-5R. Double N-methylated compound 18 showed a p Ki of 8.73 ± 0.08 ( Ki = 1.92 ± 0.34 nM) and a pEC50 of 9.13 ± 0.04 (EC50 = 0.75 ± 0.08 nM) at the human MC1R and was over 100 times more selective for MC1R. Nuclear magnetic resonance structural analysis of 18 emphasized the role of peptide bond N-methylation in shaping the conformation of the grafted pharmacophore. More broadly, this study highlights the potential of cyclic peptide scaffolds for epitope grafting in combination with N-methylation to introduce receptor subtype selectivity in the context of peptide-based drug discovery.
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Affiliation(s)
- Thomas Durek
- Institute for Molecular Bioscience , The University of Queensland , Brisbane , QLD 4072 , Australia
| | - Philipp M Cromm
- Institute for Molecular Bioscience , The University of Queensland , Brisbane , QLD 4072 , Australia.,Institute for Advanced Study and Center of Integrated Protein Science, Department Chemie , Technische Universität München , Lichtenbergstrasse 4 , 85747 Garching , Germany
| | - Andrew M White
- Institute for Molecular Bioscience , The University of Queensland , Brisbane , QLD 4072 , Australia
| | - Christina I Schroeder
- Institute for Molecular Bioscience , The University of Queensland , Brisbane , QLD 4072 , Australia
| | - Quentin Kaas
- Institute for Molecular Bioscience , The University of Queensland , Brisbane , QLD 4072 , Australia
| | - Joachim Weidmann
- Institute for Molecular Bioscience , The University of Queensland , Brisbane , QLD 4072 , Australia
| | - Abdullah Ahmad Fuaad
- Institute for Molecular Bioscience , The University of Queensland , Brisbane , QLD 4072 , Australia
| | - Olivier Cheneval
- Institute for Molecular Bioscience , The University of Queensland , Brisbane , QLD 4072 , Australia
| | - Peta J Harvey
- Institute for Molecular Bioscience , The University of Queensland , Brisbane , QLD 4072 , Australia
| | - Norelle L Daly
- Institute for Molecular Bioscience , The University of Queensland , Brisbane , QLD 4072 , Australia
| | - Yang Zhou
- Department of Chemistry and Biochemistry , University of Arizona , Tucson , Arizona 85721 , United States
| | - Anita Dellsén
- Mechanistic Biology & Profiling, Discovery Sciences, IMED Biotech Unit , AstraZeneca , Gothenburg 43183 Sweden
| | - Torben Österlund
- Discovery Biology, Discovery Sciences, IMED Biotech Unit , AstraZeneca , Gothenburg 43183 Sweden.,Drug Safety and Metabolism, IMED Biotech Unit , AstraZeneca , Gothenburg 43183 Sweden
| | - Niklas Larsson
- Discovery Biology, Discovery Sciences, IMED Biotech Unit , AstraZeneca , Gothenburg 43183 Sweden
| | - Laurent Knerr
- Medicinal Chemistry, Cardiovascular and Metabolic Diseases, IMED Biotech Unit , AstraZeneca , Gothenburg 43183 Sweden
| | - Udo Bauer
- Medicinal Chemistry, Cardiovascular and Metabolic Diseases, IMED Biotech Unit , AstraZeneca , Gothenburg 43183 Sweden
| | - Horst Kessler
- Institute for Advanced Study and Center of Integrated Protein Science, Department Chemie , Technische Universität München , Lichtenbergstrasse 4 , 85747 Garching , Germany
| | - Minying Cai
- Department of Chemistry and Biochemistry , University of Arizona , Tucson , Arizona 85721 , United States
| | - Victor J Hruby
- Department of Chemistry and Biochemistry , University of Arizona , Tucson , Arizona 85721 , United States
| | - Alleyn T Plowright
- Medicinal Chemistry, Cardiovascular and Metabolic Diseases, IMED Biotech Unit , AstraZeneca , Gothenburg 43183 Sweden
| | - David J Craik
- Institute for Molecular Bioscience , The University of Queensland , Brisbane , QLD 4072 , Australia
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30
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Gonçalves JPL, Palmer D, Meldal M. MC4R Agonists: Structural Overview on Antiobesity Therapeutics. Trends Pharmacol Sci 2018; 39:402-423. [PMID: 29478721 DOI: 10.1016/j.tips.2018.01.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 01/28/2018] [Accepted: 01/30/2018] [Indexed: 01/08/2023]
Abstract
The melanocortin-4 receptor (MC4R) regulates adipose tissue formation and energy homeostasis, and is believed to be a monogenic target for novel antiobesity therapeutics. Several research efforts targeting this receptor have identified potent and selective agonists. While viable agonists have been characterized in vitro, undesirable side effects frequently appeared during clinical trials. The most promising candidates have diverse structures, including linear peptides, cyclic peptides, and small molecules. Herein, we present a compilation of potent MC4R agonists and discuss the pivotal structural differences within those molecules that resulted in good selectivity for MC4R over other melanocortins. We provide insight on recent progress in the field and reflect on directions for development of new agonists.
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Affiliation(s)
- Juliana Pereira Lopes Gonçalves
- Center for Evolutionary Chemical Biology, Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark.
| | - Daniel Palmer
- Center for Evolutionary Chemical Biology, Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark
| | - Morten Meldal
- Center for Evolutionary Chemical Biology, Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark.
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31
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Martin-Gómez H, Tulla-Puche J. Lasso peptides: chemical approaches and structural elucidation. Org Biomol Chem 2018; 16:5065-5080. [DOI: 10.1039/c8ob01304g] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The diverse functionality and the extraordinary stability of lasso peptides make these molecules attractive scaffolds for drug discovery. The ability to generate lasso peptides chemically remains a challenging endeavor.
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Affiliation(s)
| | - Judit Tulla-Puche
- Department of Inorganic and Organic Chemistry – Organic Chemistry Section
- University of Barcelona
- Barcelona
- Spain
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32
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Camarero JA. Cyclotides, a versatile ultrastable micro-protein scaffold for biotechnological applications. Bioorg Med Chem Lett 2017; 27:5089-5099. [PMID: 29110985 PMCID: PMC5812341 DOI: 10.1016/j.bmcl.2017.10.051] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 10/13/2017] [Accepted: 10/21/2017] [Indexed: 01/26/2023]
Abstract
Cyclotides are fascinating microproteins (≈30-40 residues long) with a unique head-to-tail cyclized backbone, stabilized by three disulfide bonds forming a cystine knot. This unique topology makes them exceptionally stable to chemical, thermal and biological degradation compared to other peptides of similar size. Cyclotides have been also found to be highly tolerant to sequence variability, aside from the conserved residues forming the cystine knot, able to cross cellular membranes and modulate intracellular protein-protein interactions both in vitro and in vivo. These properties make them ideal scaffolds for many biotechnological applications. This article provides and overview of the properties of cyclotides and their applications as molecular imaging agents and peptide-based therapeutics.
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Affiliation(s)
- Julio A Camarero
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089-9121, USA; Department of Chemistry, University of Southern California, Los Angeles, CA 90089-9121, USA.
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33
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Hellinger R, Thell K, Vasileva M, Muhammad T, Gunasekera S, Kümmel D, Göransson U, Becker CW, Gruber CW. Chemical Proteomics for Target Discovery of Head-to-Tail Cyclized Mini-Proteins. Front Chem 2017; 5:73. [PMID: 29075625 PMCID: PMC5641551 DOI: 10.3389/fchem.2017.00073] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 09/19/2017] [Indexed: 11/24/2022] Open
Abstract
Target deconvolution is one of the most challenging tasks in drug discovery, but a key step in drug development. In contrast to small molecules, there is a lack of validated and robust methodologies for target elucidation of peptides. In particular, it is difficult to apply these methods to cyclic and cysteine-stabilized peptides since they exhibit reduced amenability to chemical modification and affinity capture; however, such ribosomally synthesized and post-translationally modified peptide natural products are rich sources of promising drug candidates. For example, plant-derived circular peptides called cyclotides have recently attracted much attention due to their immunosuppressive effects and oral activity in the treatment of multiple sclerosis in mice, but their molecular target has hitherto not been reported. In this study, a chemical proteomics approach using photo-affinity crosslinking was developed to determine a target for the circular peptide [T20K]kalata B1. Using this prototypic nature-derived peptide enabled the identification of a possible functional modulation of 14-3-3 proteins. This biochemical interaction was validated via competition pull down assays as well as a cellular reporter assay indicating an effect on 14-3-3-dependent transcriptional activity. As proof of concept, the presented approach may be applicable for target elucidation of various cyclic peptides and mini-proteins, in particular cyclotides, which represent a promising class of molecules in drug discovery and development.
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Affiliation(s)
- Roland Hellinger
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Kathrin Thell
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Mina Vasileva
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Taj Muhammad
- Division of Pharmacognosy, Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
| | - Sunithi Gunasekera
- Division of Pharmacognosy, Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
| | - Daniel Kümmel
- School of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany
| | - Ulf Göransson
- Division of Pharmacognosy, Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
| | - Christian W Becker
- Department of Chemistry, Institute of Biological Chemistry, University of Vienna, Vienna, Austria
| | - Christian W Gruber
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria.,School of Biomedical Sciences, Faculty of Medicine, University of Queensland, St. Lucia, QLD, Australia
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34
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Fahradpour M, Keov P, Tognola C, Perez-Santamarina E, McCormick PJ, Ghassempour A, Gruber CW. Cyclotides Isolated from an Ipecac Root Extract Antagonize the Corticotropin Releasing Factor Type 1 Receptor. Front Pharmacol 2017; 8:616. [PMID: 29033832 PMCID: PMC5627009 DOI: 10.3389/fphar.2017.00616] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 08/23/2017] [Indexed: 12/22/2022] Open
Abstract
Cyclotides are plant derived, cystine-knot stabilized peptides characterized by their natural abundance, sequence variability and structural plasticity. They are abundantly expressed in Rubiaceae, Psychotrieae in particular. Previously the cyclotide kalata B7 was identified to modulate the human oxytocin and vasopressin G protein-coupled receptors (GPCRs), providing molecular validation of the plants' uterotonic properties and further establishing cyclotides as valuable source for GPCR ligand design. In this study we screened a cyclotide extract derived from the root powder of the South American medicinal plant ipecac (Carapichea ipecacuanha) for its GPCR modulating activity of the corticotropin-releasing factor type 1 receptor (CRF1R). We identified and characterized seven novel cyclotides. One cyclotide, caripe 8, isolated from the most active fraction, was further analyzed and found to antagonize the CRF1R. A nanomolar concentration of this cyclotide (260 nM) reduced CRF potency by ∼4.5-fold. In contrast, caripe 8 did not inhibit forskolin-, or vasopressin-stimulated cAMP responses at the vasopressin V2 receptor, suggesting a CRF1R-specific mode-of-action. These results in conjunction with our previous findings establish cyclotides as modulators of both classes A and B GPCRs. Given the diversity of cyclotides, our data point to other cyclotide-GPCR interactions as potentially important sources of drug-like molecules.
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Affiliation(s)
- Mohsen Fahradpour
- Center for Physiology and Pharmacology, Medical University of ViennaVienna, Austria.,Medicinal Plants and Drugs Research Institute, Shahid Beheshti UniversityTehran, Iran
| | - Peter Keov
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, BrisbaneQLD, Australia
| | - Carlotta Tognola
- Center for Physiology and Pharmacology, Medical University of ViennaVienna, Austria
| | | | - Peter J McCormick
- School of Veterinary Medicine, University of SurreyGuildford, United Kingdom
| | - Alireza Ghassempour
- Medicinal Plants and Drugs Research Institute, Shahid Beheshti UniversityTehran, Iran
| | - Christian W Gruber
- Center for Physiology and Pharmacology, Medical University of ViennaVienna, Austria.,Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, BrisbaneQLD, Australia
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35
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Recent advances in the development of novel protein scaffolds based therapeutics. Int J Biol Macromol 2017; 102:630-641. [DOI: 10.1016/j.ijbiomac.2017.04.045] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 04/10/2017] [Accepted: 04/11/2017] [Indexed: 12/21/2022]
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36
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Craik DJ, Lee MH, Rehm FBH, Tombling B, Doffek B, Peacock H. Ribosomally-synthesised cyclic peptides from plants as drug leads and pharmaceutical scaffolds. Bioorg Med Chem 2017; 26:2727-2737. [PMID: 28818463 DOI: 10.1016/j.bmc.2017.08.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 07/12/2017] [Accepted: 08/06/2017] [Indexed: 12/28/2022]
Abstract
Owing to their exceptional stability and favourable pharmacokinetic properties, plant-derived cyclic peptides have recently attracted significant attention in the field of peptide-based drug design. This article describes the three major classes of ribosomally-synthesised plant peptides - the cyclotides, the PawS-derived peptides and the orbitides - and reviews their applications as leads or scaffolds in drug design. These ribosomally-produced peptides have a range of biological activities, including anti-HIV, cytotoxic and immunomodulatory activity. In addition, recent interest has focused on their use as scaffolds to stabilise bioactive peptide sequences, thereby enhancing their biopharmaceutical properties. There are now more than 30 published papers on such 'grafting' applications, most of which have been reported only in the last few years, and several such studies have reported in vivo activity of orally delivered cyclic peptides. In this article, we describe approaches to the synthesis of cyclic peptides and their pharmaceutically-grafted derivatives as well as outlining their biosynthetic routes. Finally, we describe possible bioproduction routes for pharmaceutically active cyclic peptides, involving plants and plant suspension cultures.
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Affiliation(s)
- David J Craik
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia.
| | - Meng-Han Lee
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Fabian B H Rehm
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Benjamin Tombling
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Benjamin Doffek
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Hayden Peacock
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
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37
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Valeur E, Guéret SM, Adihou H, Gopalakrishnan R, Lemurell M, Waldmann H, Grossmann TN, Plowright AT. New Modalities for Challenging Targets in Drug Discovery. Angew Chem Int Ed Engl 2017; 56:10294-10323. [PMID: 28186380 DOI: 10.1002/anie.201611914] [Citation(s) in RCA: 233] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 01/31/2017] [Indexed: 12/11/2022]
Abstract
Our ever-increasing understanding of biological systems is providing a range of exciting novel biological targets, whose modulation may enable novel therapeutic options for many diseases. These targets include protein-protein and protein-nucleic acid interactions, which are, however, often refractory to classical small-molecule approaches. Other types of molecules, or modalities, are therefore required to address these targets, which has led several academic research groups and pharmaceutical companies to increasingly use the concept of so-called "new modalities". This Review defines for the first time the scope of this term, which includes novel peptidic scaffolds, oligonucleotides, hybrids, molecular conjugates, as well as new uses of classical small molecules. We provide the most representative examples of these modalities to target large binding surface areas such as those found in protein-protein interactions and for biological processes at the center of cell regulation.
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Affiliation(s)
- Eric Valeur
- Cardiovascular and Metabolic Diseases, Innovative Medicines and Early Development Biotech Unit, AstraZeneca, Pepparedsleden 1, Mölndal, 431 83, Sweden
| | - Stéphanie M Guéret
- Cardiovascular and Metabolic Diseases, Innovative Medicines and Early Development Biotech Unit, AstraZeneca, Pepparedsleden 1, Mölndal, 431 83, Sweden.,AstraZeneca MPI Satellite Unit, Abteilung Chemische Biologie, Max Planck Institut für Molekulare Physiologie, Dortmund, Germany
| | - Hélène Adihou
- Cardiovascular and Metabolic Diseases, Innovative Medicines and Early Development Biotech Unit, AstraZeneca, Pepparedsleden 1, Mölndal, 431 83, Sweden.,AstraZeneca MPI Satellite Unit, Abteilung Chemische Biologie, Max Planck Institut für Molekulare Physiologie, Dortmund, Germany
| | - Ranganath Gopalakrishnan
- Cardiovascular and Metabolic Diseases, Innovative Medicines and Early Development Biotech Unit, AstraZeneca, Pepparedsleden 1, Mölndal, 431 83, Sweden.,AstraZeneca MPI Satellite Unit, Abteilung Chemische Biologie, Max Planck Institut für Molekulare Physiologie, Dortmund, Germany
| | - Malin Lemurell
- Cardiovascular and Metabolic Diseases, Innovative Medicines and Early Development Biotech Unit, AstraZeneca, Pepparedsleden 1, Mölndal, 431 83, Sweden
| | - Herbert Waldmann
- Abteilung Chemische Biologie, Max Planck Institut für Molekulare Physiologie, Dortmund, Germany.,Fakultät für Chemie und Chemische Biologie, Technische Universität Dortmund, Germany
| | - Tom N Grossmann
- Chemical Genomics Centre of the Max Planck Society, Dortmund, Germany.,Department of Chemistry & Pharmaceutical Sciences, VU University Amsterdam, The Netherlands
| | - Alleyn T Plowright
- Cardiovascular and Metabolic Diseases, Innovative Medicines and Early Development Biotech Unit, AstraZeneca, Pepparedsleden 1, Mölndal, 431 83, Sweden
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38
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Valeur E, Guéret SM, Adihou H, Gopalakrishnan R, Lemurell M, Waldmann H, Grossmann TN, Plowright AT. Neue Modalitäten für schwierige Zielstrukturen in der Wirkstoffentwicklung. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201611914] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Eric Valeur
- Cardiovascular and Metabolic Diseases; Innovative Medicines and Early Development Biotech Unit; AstraZeneca; Pepparedsleden 1 Mölndal 431 83 Schweden
| | - Stéphanie M. Guéret
- Cardiovascular and Metabolic Diseases; Innovative Medicines and Early Development Biotech Unit; AstraZeneca; Pepparedsleden 1 Mölndal 431 83 Schweden
- AstraZeneca MPI Satellite Unit; Abteilung Chemische Biologie; Max-Planck-Institut für Molekulare Physiologie; Dortmund Deutschland
| | - Hélène Adihou
- Cardiovascular and Metabolic Diseases; Innovative Medicines and Early Development Biotech Unit; AstraZeneca; Pepparedsleden 1 Mölndal 431 83 Schweden
- AstraZeneca MPI Satellite Unit; Abteilung Chemische Biologie; Max-Planck-Institut für Molekulare Physiologie; Dortmund Deutschland
| | - Ranganath Gopalakrishnan
- Cardiovascular and Metabolic Diseases; Innovative Medicines and Early Development Biotech Unit; AstraZeneca; Pepparedsleden 1 Mölndal 431 83 Schweden
- AstraZeneca MPI Satellite Unit; Abteilung Chemische Biologie; Max-Planck-Institut für Molekulare Physiologie; Dortmund Deutschland
| | - Malin Lemurell
- Cardiovascular and Metabolic Diseases; Innovative Medicines and Early Development Biotech Unit; AstraZeneca; Pepparedsleden 1 Mölndal 431 83 Schweden
| | - Herbert Waldmann
- Abteilung Chemische Biologie; Max-Planck-Institut für Molekulare Physiologie; Dortmund Deutschland
- Fakultät für Chemie and Chemische Biologie; Technische Universität Dortmund; Deutschland
| | - Tom N. Grossmann
- Chemical Genomics Centre der Max-Planck-Gesellschaft; Dortmund Deutschland
- Department of Chemistry & Pharmaceutical Sciences; VU University Amsterdam; Niederlande
| | - Alleyn T. Plowright
- Cardiovascular and Metabolic Diseases; Innovative Medicines and Early Development Biotech Unit; AstraZeneca; Pepparedsleden 1 Mölndal 431 83 Schweden
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39
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Abstract
Cyclotides are globular microproteins with a unique head-to-tail cyclized backbone, stabilized by three disulfide bonds forming a cystine knot. This unique circular backbone topology and knotted arrangement of three disulfide bonds makes them exceptionally stable to chemical, thermal, and biological degradation compared to other peptides of similar size. In addition, cyclotides have been shown to be highly tolerant to sequence variability, aside from the conserved residues forming the cystine knot. Cyclotides can also cross cellular membranes and are able to modulate intracellular protein-protein interactions, both in vitro and in vivo. All of these features make cyclotides highly promising as leads or frameworks for the design of peptide-based diagnostic and therapeutic tools. This article provides an overview on cyclotides and their applications as molecular imaging agents and peptide-based therapeutics.
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Affiliation(s)
- Andrew Gould
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089-9121, USA
| | - Julio A. Camarero
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089-9121, USA
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089-9121, USA
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40
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Abstract
Among the various molecules that plants produce for defense against pests and pathogens, cyclotides stand out as exceptionally stable and structurally unique. These ribosomally synthesized peptides are around 30 amino acids in size, and are stabilized by a head-to-tail cyclic peptide backbone and three disulfide bonds that form a cystine knot. They occur in certain plants of the Rubiaceae, Violaceae, Cucurbitaceae, Fabaceae, and Solanaceae families, with an individual plant producing up to hundreds of different cyclotides. Aside from being exploitable as crop protection agents based on their natural pesticidal activities, cyclotides are amenable to repurposing by chemists for use as drug leads or as tools in chemical biology. Their macrocyclic peptide backbone and knotted arrangement of three disulfide bonds engenders cyclotides with resistance to proteolytic degradation, high temperatures, and chemical chaotropes. Furthermore, their small size makes them accessible to synthesis using solid-phase peptide chemistry and so non-natural cyclotides can be designed and synthesized for a variety of applications. Our focus here is on cyclotides as tools in chemical biology, and there are four main areas of application that have appeared in the literature so far: (i) cyclotides as probes of membrane binding; (ii) cyclotides as probes of biosynthetic pathways for peptide cyclization; (iii) cyclotides as probes of protease specificity and function; and (iv) cyclotides as probes of receptor binding and specificity, with the potential for them to be developed as drug leads. The main methods used in these studies include solid-phase peptide chemistry for synthesis and NMR spectroscopy for structural characterization, as well as a wide range of biochemical and biophysical techniques for probing intermolecular interactions. In addition, cyclotides have been examined in diverse biological assays, ranging from enzyme inhibition to cell penetration, intracellular targeting and cytotoxicity. The main finding to have emerged from studies over the past decade is that cyclotides are exceptionally stable under a variety of conditions (in assay buffers, biological fluids, membranes, and recombinant expression systems). Furthermore, they are structurally very well-defined and amenable to sequence substitutions that can introduce new desired biological activities, generally without compromising their exceptional stability. Both features contribute to their use as peptide-based frameworks in drug design. Finally, they occupy a size niche between traditional small-molecule drugs (<500 Da in molecular weight) and protein-based biologics (>5000 Da) and thus can probe receptors, membranes, and protein-protein interactions in different ways to what is possible with either small molecules or biologics. Overall, cyclotides are an exciting class of peptides that have great potential as ultrastable chemical biology probes in a variety of applications. They have the advantage of specificity (typical of proteins) combined with the synthetic accessibility of small molecules.
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Affiliation(s)
- Simon J. de Veer
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Joachim Weidmann
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - David J. Craik
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
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41
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Abstract
INTRODUCTION The melanocortin system is a primordial and critical system for survival, involved in a wide variety of physiological functions. It includes melanocortin receptors (MCRs) and melanotropin ligands (MCLs). MCRs are important drug targets that can regulate several key physiological processes. Extensive efforts have been made to develop peptide and peptidomimetics targeting melanocortin receptors including MC1R, MC3R, MC4R and MC5R. Most research is focused on developing potent and selective melanotropins. However, developing bioavailable melanotropins remains challenging. Areas covered: Herein, the authors summarize promising strategies for developing bioavailable MCLs by using cyclized N-methylated melanotropins, and using cyclotide and tetrapeptide as templates. They discuss their unique advantages in oral availability and targeting MCRs in the central nervous system or in peripheral tissues. Finally, they discuss the observed differences in thepharmacology of MCRs between in vitro and in vivo tests. Expert opinion: N-methylated cyclized melanotropins have great potential to become bio- available drugs targeting MCRs in the brain, while MCR-grafted cyclotides tend to target MCRs in peripheral tissue. A better understanding of the biased signaling process is a new challenge and opportunity for the future discovery of bioavailable MCLs.
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Affiliation(s)
- Yang Zhou
- a Department of Chemistry and Biochemistry , University of Arizona , Tucson , AZ USA
| | - Minying Cai
- a Department of Chemistry and Biochemistry , University of Arizona , Tucson , AZ USA
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Cyclotides as drug design scaffolds. Curr Opin Chem Biol 2017; 38:8-16. [DOI: 10.1016/j.cbpa.2017.01.018] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 01/27/2017] [Indexed: 11/21/2022]
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Cai M, Hruby VJ. Design of cyclized selective melanotropins. Biopolymers 2017; 106:876-883. [PMID: 27561155 DOI: 10.1002/bip.22976] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Revised: 08/19/2016] [Accepted: 08/22/2016] [Indexed: 01/02/2023]
Abstract
This article describes the development of cyclic peptides for G-protein coupled receptors to enable structure-function knowledge and the design of novel therapeutics. One important property of cyclic peptides is that they tend to be resistant to the digestion, enabling them to survive in the human digestive tract. This trait makes them very important as drug leads or as scaffolds which, in theory, can be engineered to incorporate a peptide domain of medicinal value. This is especially important for delivery of peptides that would be destroyed without such implementation. The melanocortin system is the focus of this article, and includes melanotropin ligands and melanocortin receptors. We examine two strategies to constrain the melanotropin peptide backbone. The first is based on global constraint of peptides by cyclization using various kinds of linkers. In the second approach we describe the use of a natural cyclized template, the cyclotide, to graft the melanotropin phamacophore, -His-Phe-Arg-Trp-, to obtain selective drug leads. In these examples the conserved melanocyte stimulating hormone pharmacophore is examined and the modified peptides were synthesized by solid phase methodology. Biological studies confirmed the production of selective, potent and in some cases orally available ligands.
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Affiliation(s)
- Minying Cai
- Department of Chemistry & Biochemistry, University of Arizona, 1306 E University Blvd, Tucson, AZ, 85721
| | - Victor J Hruby
- Department of Chemistry & Biochemistry, University of Arizona, 1306 E University Blvd, Tucson, AZ, 85721
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Troeira Henriques S, Craik DJ. Cyclotide Structure and Function: The Role of Membrane Binding and Permeation. Biochemistry 2017; 56:669-682. [DOI: 10.1021/acs.biochem.6b01212] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sónia Troeira Henriques
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, 4072 QLD, Australia
| | - David J. Craik
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, 4072 QLD, Australia
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Qu H, Smithies BJ, Durek T, Craik DJ. Synthesis and Protein Engineering Applications of Cyclotides. Aust J Chem 2017. [DOI: 10.1071/ch16589] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cyclotides are a group of plant-derived peptides with a head-to-tail cyclized backbone that is stabilized by three knotted disulfide bonds. Their exceptional stability and tolerance for residue substitutions have led to interest in their application as drug design scaffolds. To date, chemical synthesis has been the dominant methodology for producing cyclotides and their analogues. Native chemical ligation is the most common strategy to generate the cyclic backbone and has been highly successful at producing a wide range of cyclotides for studies of structure–activity relationships. Both this and other chemical approaches require a specific linker at the C-terminus and typically involve a non-directed folding (disulfide oxidation) regimen, which can sometimes be a limiting factor in final yields. Following the recent discovery of enzymes involved in peptide cyclization in planta, site-specific and highly efficient enzymatic ligations have been used for synthetic cyclotide backbone cyclization. In this review, chemical synthesis strategies and approaches involving cyclization via enzymes for the production of cyclotides are described.
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Weidmann J, Craik DJ. Discovery, structure, function, and applications of cyclotides: circular proteins from plants. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:4801-12. [PMID: 27222514 DOI: 10.1093/jxb/erw210] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Cyclotides are plant-derived cyclic peptides that have a head-to-tail cyclic backbone and three conserved disulphide bonds that form a cyclic cystine knot motif. They occur in plants from the Violaceae, Rubiaceae, Cucurbitaceae, Fabaceae, and Solanaceae families, typically with 10-100 cyclotides in a given plant species, in a wide range of tissues, including flowers, leaves, stems, and roots. Some cyclotides are expressed in large amounts (up to 1g kg(-1) wet plant weight) and their natural function appears to be to protect plants from pests or pathogens. This article provides a brief overview of their discovery, distribution in plants, and applications. In particular, their exceptional stability has led to their use as peptide-based scaffolds in drug design applications. They also have potential as natural 'ecofriendly' insecticides, and as protein engineering frameworks.
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Affiliation(s)
- Joachim Weidmann
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - David J Craik
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
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Poth AG, Chan LY, Craik DJ. Cyclotides as grafting frameworks for protein engineering and drug design applications. Biopolymers 2016; 100:480-91. [PMID: 23893608 DOI: 10.1002/bip.22284] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2013] [Revised: 04/30/2013] [Accepted: 05/07/2013] [Indexed: 11/08/2022]
Abstract
Cyclotides are a family of naturally occurring backbone-cyclized macrocyclic mini-proteins from plants that have a knotted trio of intramolecular disulfide bonds. Their structural features imbue cyclotides with extraordinary stability against degradation at elevated temperatures or in the presence of proteolytic enzymes. The plasticity of their intracysteine loop sequences is exemplified by the more than 250 natural cyclotides sequenced to date, and this tolerance to sequence variation, along with their diverse bioactivities, underpins the suitability of the cyclic cystine knot motif as a valuable drug design scaffold and research tool for protein engineering studies. Here, we review the recent literature on applications of cyclotides for the stabilization of peptide epitopes and related protein engineering studies. Possible future directions in this field are also described.
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Affiliation(s)
- Aaron G Poth
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, 4072, Australia
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Synthetic Cystine-Knot Miniproteins - Valuable Scaffolds for Polypeptide Engineering. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 917:121-44. [PMID: 27236555 DOI: 10.1007/978-3-319-32805-8_7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Peptides with the cystine-knot architecture, often termed knottins, are promising scaffolds for biomolecular engineering. These unique molecules combine diverse bioactivities with excellent structural, thermal, and proteolytical stability. Being different in the composition and structure of their amino acid backbone, knottins share the same core element, namely cystine knot, which is built by six cysteine residues forming three disulfides upon oxidative folding. This motif ensures a notably rigid framework that highly tolerates both rational and combinatorial changes in the primary structure. Being accessible through recombinant production and total chemical synthesis, cystine-knot miniproteins can be endowed with novel bioactivities by variation of surface-exposed loops and incorporation of non-natural elements within their non-conserved regions towards the generation of tailor-made peptidic compounds. In this chapter the topology of cystine-knot peptides, their synthesis and applications for diagnostics and therapy is discussed.
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Tam JP, Wang S, Wong KH, Tan WL. Antimicrobial Peptides from Plants. Pharmaceuticals (Basel) 2015; 8:711-57. [PMID: 26580629 PMCID: PMC4695807 DOI: 10.3390/ph8040711] [Citation(s) in RCA: 276] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 08/06/2015] [Accepted: 09/01/2015] [Indexed: 12/25/2022] Open
Abstract
Plant antimicrobial peptides (AMPs) have evolved differently from AMPs from other life forms. They are generally rich in cysteine residues which form multiple disulfides. In turn, the disulfides cross-braced plant AMPs as cystine-rich peptides to confer them with extraordinary high chemical, thermal and proteolytic stability. The cystine-rich or commonly known as cysteine-rich peptides (CRPs) of plant AMPs are classified into families based on their sequence similarity, cysteine motifs that determine their distinctive disulfide bond patterns and tertiary structure fold. Cystine-rich plant AMP families include thionins, defensins, hevein-like peptides, knottin-type peptides (linear and cyclic), lipid transfer proteins, α-hairpinin and snakins family. In addition, there are AMPs which are rich in other amino acids. The ability of plant AMPs to organize into specific families with conserved structural folds that enable sequence variation of non-Cys residues encased in the same scaffold within a particular family to play multiple functions. Furthermore, the ability of plant AMPs to tolerate hypervariable sequences using a conserved scaffold provides diversity to recognize different targets by varying the sequence of the non-cysteine residues. These properties bode well for developing plant AMPs as potential therapeutics and for protection of crops through transgenic methods. This review provides an overview of the major families of plant AMPs, including their structures, functions, and putative mechanisms.
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Affiliation(s)
- James P Tam
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
| | - Shujing Wang
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
- Department of Pharmacology and Pharmaceutical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China.
| | - Ka H Wong
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
| | - Wei Liang Tan
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
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