1
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Jiang Z, Huang YH, Kaas Q, Craik DJ, Wang CK. Structure and Activity of Reconstructed Pseudo-Ancestral Cyclotides. ChemMedChem 2024:e202400124. [PMID: 38632079 DOI: 10.1002/cmdc.202400124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 04/17/2024] [Accepted: 04/17/2024] [Indexed: 04/19/2024]
Abstract
Cyclotides are cyclic peptides that are promising scaffolds for the design of drug candidates and chemical tools. However, despite there being hundreds of reported cyclotides, drug design studies have commonly focussed on a select few prototypic examples. Here, we explored whether ancestral sequence reconstruction could be used to generate new cyclotides for further optimization. We show that the reconstructed 'pseudo-ancestral' sequences, named Ancy-m (for the ancestral cyclotide of the Möbius sub-family) and Ancy-b (for the bracelet sub-family), have well-defined structures like their extant members, comprising the core structural feature of a cyclic cystine knot. This motif underpins efforts to re-engineer cyclotides for agrochemical and therapeutic applications. We further show that the reconstructed sequences are resistant to temperatures approaching boiling, bind to phosphatidyl-ethanolamine lipid bilayers at micromolar affinity, and inhibit the growth of insect cells at inhibitory concentrations in the micromolar range. Interestingly, the Ancy-b cyclotide had a higher oxidative folding yield than its comparator cyclotide cyO2, which belongs to the bracelet cyclotide subfamily known to be notoriously difficult to fold. Overall, this study provides new cyclotide sequences not yet found naturally that could be valuable starting points for the understanding of cyclotide evolution and for further optimization as drug leads.
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Affiliation(s)
- Zhihao Jiang
- 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
| | - Yen-Hua Huang
- 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
| | - Quentin Kaas
- 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
| | - 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, Qld, 4072, Australia
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2
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Dang TT, Tran TTT, Tran GH, Pham SH, Nguyen THN. Cyclotides derived from Viola dalatensis Gagnep: A novel approach for enrichment and evaluation of antimicrobial activity. Toxicon 2024; 239:107606. [PMID: 38181837 DOI: 10.1016/j.toxicon.2024.107606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 12/25/2023] [Accepted: 01/03/2024] [Indexed: 01/07/2024]
Abstract
Cyclotides, plant-derived cysteine-rich peptides, exhibit a wide range of beneficial biological activities and possess exceptional structural stability. Cyclotides are commonly distributed throughout the Violaceae family. Viola dalatensis Gagnep, a Vietnamese species, has not been well studied, especially for cyclotides. This pioneering research explores cyclotides from V. dalatensis as antimicrobials. This study used a novel approach to enhance cyclotides after extraction. The approach combined 30% ammonium sulfate salt precipitation and RP-HPLC. A comprehensive analysis was performed to ascertain the overall protein content, flavonoids content, polyphenol content, and free radical scavenging capacity of compounds derived from V. dalatensis. Six known cyclotides were sequenced utilizing MS tandem. Semi-purified cyclotide mixtures (M1, M2, and M3) exhibited antibacterial efficacy against Bacillus subtilis (inhibitory diameters: 19.67-23.50 mm), Pseudomonas aeruginosa (22.17-23.50 mm), and Aspergillus flavus (14.67-21.33 mm). The enriched cyclotide precipitate from the stem extract demonstrated a minimum inhibitory concentration (MIC) of 0.08 mg/mL against P. aeruginosa, showcasing significant antibacterial effectiveness compared to the stem extract (MIC: 12.50 mg/mL). Considerable advancements have been achieved in the realm of cyclotides, specifically in their application as antimicrobial agents.
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Affiliation(s)
- Tien T Dang
- Institute of Applied Materials Science, Vietnam Academy of Science and Technology, 1B TL29, District 12, Ho Chi Minh City, Viet Nam.
| | - Tam T T Tran
- Institute of Applied Materials Science, Vietnam Academy of Science and Technology, 1B TL29, District 12, Ho Chi Minh City, Viet Nam
| | - Gia-Hoa Tran
- Institute of Applied Materials Science, Vietnam Academy of Science and Technology, 1B TL29, District 12, Ho Chi Minh City, Viet Nam
| | - Son H Pham
- Institute of Applied Materials Science, Vietnam Academy of Science and Technology, 1B TL29, District 12, Ho Chi Minh City, Viet Nam
| | - Tuan H N Nguyen
- Biomedical Research Center, Pham Ngoc Thach University of Medicine, Viet Nam; Department of Medical Biochemistry & Molecular Biology, Pham Ngoc Thach University of Medicine, Viet Nam
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3
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Carcache de Blanco EJ, Addo EM, Rakotondraibe HL, Soejarto DD, Kinghorn AD. Strategies for the discovery of potential anticancer agents from plants collected from Southeast Asian tropical rainforests as a case study. Nat Prod Rep 2023; 40:1181-1197. [PMID: 37194649 PMCID: PMC10524867 DOI: 10.1039/d2np00080f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Covering up to early 2023The present review summarizes recent accomplishments made as part of a multidisciplinary, multi-institutional anticancer drug discovery project, wherein samples comprising higher plants were collected primarily from Southeast Asia, and also from Central America, and the West Indies. In the introductory paragraphs, a short perspective is provided on the current importance of plants in the discovery of cancer therapeutic agents, and the contributions of other groups working towards this objective are mentioned. For our own investigations, following their collection, tropical plants have been subjected to solvent extraction and biological evaluation for their antitumor potential. Several examples of purified plant lead bioactive compounds were obtained and characterized, and found to exhibit diverse structures, including those of the alkaloid, cardiac glycoside, coumarin, cucurbitacin, cyclobenzofuran (rocaglate), flavonoid, lignan, and terpenoid types. In order to maximize the efficiency of work on drug discovery from tropical plant species, strategies to optimize various research components have been developed, including those for the plant collections and taxonomic identification, in accordance with the requirements of contemporary international treaties and with a focus on species conservation. A major component of this aspect of the work is the development of collaborative research agreements with representatives of the source countries of tropical rainforest plants. The phytochemical aspects have included the preparation of plant extracts for initial screening and the selection of promising extracts for activity-guided fractionation. In an attempt to facilitate this process, a TOCSY-based NMR procedure has been applied for the determination of bioactive rocaglate derivatives in samples of Aglaia species (Meliaceae) collected for the project. Preliminary in vitro and in vivo mechanistic studies carried out by the authors are described for two tropical plant-derived bioactive lead compounds, corchorusoside C and (+)-betulin, including work conducted with a zebrafish (Danio rerio) model. In the concluding remarks, a number of lessons are summarized that our group has learned as a result of working on anticancer drug discovery using tropical plants, which we hope will be of interest to future workers.
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Affiliation(s)
- Esperanza J Carcache de Blanco
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio 43210, USA.
| | - Ermias Mekuria Addo
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio 43210, USA.
| | - H Liva Rakotondraibe
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio 43210, USA.
| | - Djaja D Soejarto
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, USA
- Science and Education, Field Museum, Chicago, IL 60605, USA
| | - A Douglas Kinghorn
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio 43210, USA.
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4
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Bajpai A, Jackson MA, Huang YH, Yap K, Du Q, Chau TCY, Craik DJ, Gilding EK. Nematicidal Activity of Cyclotides: Toxicity Against Caenorhabditis elegans. JOURNAL OF NATURAL PRODUCTS 2023; 86:1222-1229. [PMID: 37099442 DOI: 10.1021/acs.jnatprod.2c01124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Cyclotides are a unique family of stable and cyclic mini-proteins found in plants that have nematicidal and anthelmintic activities. They are distributed across the Rubiaceae, Violaceae, Fabaceae, Cucurbitaceae, and Solanaceae plant families, where they are posited to act as protective agents against pests. In this study, we tested the nematicidal properties of extracts from four major cyclotide-producing plants, Oldenlandia affinis, Clitoria ternatea, Viola odorata, and Hybanthus enneaspermus, against the free-living model nematode Caenorhabditis elegans. We evaluated the nematicidal activity of the cyclotides kalata B1, cycloviolacin O2, and hyen D present in these extracts and found them to be active against the larvae of C. elegans. Both the plant extracts and isolated cyclotides exerted dose-dependent toxicity on the first-stage larvae of C. elegans. Isolated cyclotides caused death or damage upon interacting with the worms' mouth, pharynx, and midgut or membrane. Cycloviolacin O2 and hyen D produced bubble-like structures around the C. elegans membrane, termed blebs, implicating membrane disruption causing toxicity and death. All tested cyclotides lost their toxicity when the hydrophobic patches present on them were disrupted via a single-point mutation. The present results provide a facile assay design to measure and explore the nematicidal activities of plant extracts and purified cyclotides on C. elegans.
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Affiliation(s)
- Abhishek Bajpai
- 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
| | - 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, Queensland 4072, Australia
| | - Yen-Hua Huang
- 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
| | - Kuok Yap
- 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
| | - Qingdan Du
- 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
| | - Tevin Chui-Ying Chau
- ACRF Cancer Biology Imaging Facility, Institute for Molecular Bioscience, 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
| | - 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, Queensland 4072, Australia
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5
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Rajendran S, Slazak B, Mohotti S, Muhammad T, Strömstedt AA, Kapusta M, Wilmowicz E, Göransson U, Hettiarachchi CM, Gunasekera S. Screening for Cyclotides in Sri Lankan Medicinal Plants: Discovery, Characterization, and Bioactivity Screening of Cyclotides from Geophila repens. JOURNAL OF NATURAL PRODUCTS 2023; 86:52-65. [PMID: 36525646 PMCID: PMC9887600 DOI: 10.1021/acs.jnatprod.2c00674] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Indexed: 06/17/2023]
Abstract
Cyclotides are an intriguing class of structurally stable circular miniproteins of plant origin with numerous potential pharmaceutical and agricultural applications. To investigate the occurrence of cyclotides in Sri Lankan flora, 50 medicinal plants were screened, leading to the identification of a suite of new cyclotides from Geophila repens of the family Rubiaceae. Cycloviolacin O2-like (cyO2-like) gere 1 and the known cyclotide kalata B7 (kB7) were among the cyclotides characterized at the peptide and/or transcript level together with several putative enzymes, likely involved in cyclotide biosynthesis. Five of the most abundant cyclotides were isolated, sequenced, structurally characterized, and screened in antimicrobial and cytotoxicity assays. All gere cyclotides showed cytotoxicity (IC50 of 2.0-10.2 μM), but only gere 1 inhibited standard microbial strains at a minimum inhibitory concentration of 4-16 μM. As shown by immunohistochemistry, large quantities of the cyclotides were localized in the epidermis of the leaves and petioles of G. repens. Taken together with the cytotoxicity and membrane permeabilizing activities, this implicates gere cyclotides as potential plant defense molecules. The presence of cyO2-like gere 1 in a plant in the Rubiaceae supports the notion that phylogenetically distant plants may have coevolved to express similar cytotoxic cyclotides for a specific functional role, most likely involving host defense.
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Affiliation(s)
- Sanjeevan Rajendran
- Phamacognosy,
Department of Pharmaceutical Biosciences, Uppsala University, Biomedical Centre, SE 75124 Uppsala, Sweden
- Department
of Chemistry, Faculty of Science, University
of Colombo, Thurstan Road, Colombo 00300, Sri Lanka
| | - Blazej Slazak
- Phamacognosy,
Department of Pharmaceutical Biosciences, Uppsala University, Biomedical Centre, SE 75124 Uppsala, Sweden
- W.
Szafer Institute of Botany of the Polish Academy of Sciences, 46 Lubicz, 31-512 Cracow, Poland
| | - Supun Mohotti
- Department
of Chemistry, Faculty of Science, University
of Colombo, Thurstan Road, Colombo 00300, Sri Lanka
| | - Taj Muhammad
- Phamacognosy,
Department of Pharmaceutical Biosciences, Uppsala University, Biomedical Centre, SE 75124 Uppsala, Sweden
| | - Adam A. Strömstedt
- Phamacognosy,
Department of Pharmaceutical Biosciences, Uppsala University, Biomedical Centre, SE 75124 Uppsala, Sweden
| | - Małgorzata Kapusta
- Department
of Plant Cytology and Embryology, Faculty of Biology, University of Gdańsk, 59 Wita Stwosza, 80-308 Gdańsk, Poland
| | - Emilia Wilmowicz
- Faculty
of Biological and Veterinary Sciences, Nicolaus
Copernicus University, 1 Lwowska Street, 87-100 Toruń, Poland
| | - Ulf Göransson
- Phamacognosy,
Department of Pharmaceutical Biosciences, Uppsala University, Biomedical Centre, SE 75124 Uppsala, Sweden
| | - Chamari M. Hettiarachchi
- Department
of Chemistry, Faculty of Science, University
of Colombo, Thurstan Road, Colombo 00300, Sri Lanka
| | - Sunithi Gunasekera
- Phamacognosy,
Department of Pharmaceutical Biosciences, Uppsala University, Biomedical Centre, SE 75124 Uppsala, Sweden
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6
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Ghosh A, Mukhopadhyay TK, Datta A. Two dimensional materials are non-nanotoxic and biocompatible towards cyclotides: evidence from classical molecular dynamics simulations. NANOSCALE 2022; 15:321-336. [PMID: 36484694 DOI: 10.1039/d2nr05096j] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Cyclotides are backbone-cyclized peptides of plant origin enriched with disulfide bonds, having exceptional stability towards thermal denaturation and proteolytic degradation. They have a plethora of activities like antibacterial, antifungal, anti-tumor and anti-HIV properties predominantly owing to their selective interaction with certain phospholipids, thereby leading to the disruption of cellular membranes. On the other hand, low-dimensional materials like graphene and hexagonal boron nitride (h-BN) are also known to show membrane-proliferating activities through lipid extraction. A plausible and more effective antibacterial, anti-tumor and antifungal agent would be a composite of these 2D materials and cyclotides, provided the structures of the peptides remain unperturbed upon adsorption and interaction. In this study, classical molecular dynamics simulations are performed to understand the nature of adsorption of cyclotides belonging to different families on graphene and h-BN and analyze the resulting structural changes. It is revealed that, due to their exceptional structural stability, cyclotides maintain their structural integrity upon adsorption on the 2D materials. In addition, the aggregated states of the cyclotides, which are ubiquitous in plant organs, are also not disrupted upon adsorption. Extensive free energy calculations show that the adsorption strength of the cyclotides is moderate in comparison to those of other similar-sized biomolecules, and the larger the size of the aggregates, the weaker the binding of individual peptides with the 2D materials, thereby leading to their lower release times from the materials. It is predicted that graphene and h-BN may safely be used for the preparation of composites with cyclotides, which in turn may be envisaged to be probable candidates for manufacturing next-generation bionano agents for agricultural, antibacterial and therapeutic applications.
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Affiliation(s)
- Anupam Ghosh
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Jadavpur - 700032, West Bengal, India.
| | - Titas Kumar Mukhopadhyay
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Jadavpur - 700032, West Bengal, India.
| | - Ayan Datta
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Jadavpur - 700032, West Bengal, India.
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7
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Fernández-Bobey A, Pinto MEF, de Almeida LC, de Souza BM, Dias NB, de Paula-Souza J, Cilli EM, Lopes NP, Costa-Lotufo LV, Palma MS, da Silva Bolzani V. Cytotoxic Cyclotides from Anchietea pyrifolia, a South American Plant Species. JOURNAL OF NATURAL PRODUCTS 2022; 85:2127-2134. [PMID: 36044031 DOI: 10.1021/acs.jnatprod.1c01129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Cyclotides are mini-proteins with potent bioactivities and outstanding potential for agricultural and pharmaceutical applications. More than 450 different plant cyclotides have been isolated from six angiosperm families. In Brazil, studies involving this class of natural products are still scarce, despite its rich floristic diversity. Herein were investigated the cyclotides from Anchietea pyrifolia roots, a South American medicinal plant from the family Violaceae. Fourteen putative cyclotides were annotated by LC-MS. Among these, three new bracelet cyclotides, anpy A-C, and the known cycloviolacins O4 (cyO4) and O17 (cyO17) were sequenced through a combination of chemical and enzymatic reactions followed by MALDI-MS/MS analysis. Their cytotoxic activity was evaluated by a cytotoxicity assay against three human cancer cell lines (colorectal carcinoma cells: HCT 116 and HCT 116 TP53-/- and breast adenocarcinoma, MCF 7). For all assays, the IC50 values of isolated compounds ranged between 0.8 and 7.3 μM. CyO17 was the most potent cyclotide for the colorectal cancer cell lines (IC50, 0.8 and 1.2 μM). Furthermore, the hemolytic activity of anpy A and B, cyO4, and cyO17 was assessed, and the cycloviolacins were the least hemolytic (HD50 > 156 μM). This work sheds light on the cytotoxic effects of the anpy cyclotides against cancer cells. Moreover, this study expands the number of cyclotides obtained to date from Brazilian plant biodiversity and adds one more genus containing these molecules to the list of the Violaceae family.
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Affiliation(s)
- Antonio Fernández-Bobey
- Nucleus of Bioassays, Biosynthesis, and Ecophysiology of Natural Products (NuBBE), Institute of Chemistry, Sao Paulo State University (UNESP), 14800-060, Araraquara, Sao Paulo, Brazil
- Department of Basic and Applied Biology, Laboratory of Structural Biology and Zoochemistry, Institute of Biosciences, Sao Paulo State University (UNESP), 13506-900, Rio Claro, Sao Paulo, Brazil
| | - Meri Emili Ferreira Pinto
- Nucleus of Bioassays, Biosynthesis, and Ecophysiology of Natural Products (NuBBE), Institute of Chemistry, Sao Paulo State University (UNESP), 14800-060, Araraquara, Sao Paulo, Brazil
| | - Larissa Costa de Almeida
- Department of Pharmacology, Institute of Biomedical Science, University of Sao Paulo (USP), 05508-900, Sao Paulo, Brazil
| | - Bibiana Monson de Souza
- Department of Basic and Applied Biology, Laboratory of Structural Biology and Zoochemistry, Institute of Biosciences, Sao Paulo State University (UNESP), 13506-900, Rio Claro, Sao Paulo, Brazil
| | - Nathalia Baptista Dias
- Scientific and Technological Bioresource Nucleus (BIOREN), University of The Frontier (UFRO), 4881-176, Temuco, Chile
| | - Juliana de Paula-Souza
- Department of Botany, Federal University of Santa Catarina (UFSC), 88040-535, Florianopolis, Santa Catarina, Brazil
| | - Eduardo Maffud Cilli
- Nucleus of Bioassays, Biosynthesis, and Ecophysiology of Natural Products (NuBBE), Institute of Chemistry, Sao Paulo State University (UNESP), 14800-060, Araraquara, Sao Paulo, Brazil
| | - Norberto Peporine Lopes
- Nucleus Research in Natural and Synthetic Products (NPPNS), Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of Sao Paulo (USP), 14040-903, Ribeirao Preto, Sao Paulo, Brazil
| | - Leticia Veras Costa-Lotufo
- Department of Pharmacology, Institute of Biomedical Science, University of Sao Paulo (USP), 05508-900, Sao Paulo, Brazil
| | - Mario Sergio Palma
- Department of Basic and Applied Biology, Laboratory of Structural Biology and Zoochemistry, Institute of Biosciences, Sao Paulo State University (UNESP), 13506-900, Rio Claro, Sao Paulo, Brazil
| | - Vanderlan da Silva Bolzani
- Nucleus of Bioassays, Biosynthesis, and Ecophysiology of Natural Products (NuBBE), Institute of Chemistry, Sao Paulo State University (UNESP), 14800-060, Araraquara, Sao Paulo, Brazil
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8
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Aslam L, Kaur R, Hussain S, Kapoor N, Mahajan R. LC-MS/MS identification and structural characterization of isolated cyclotides from precursor sequences of Viola odorata L. petiole tissue using computational approach. J Biosci 2022. [DOI: 10.1007/s12038-022-00283-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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9
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Dang TT, Huang YH, Ott S, Harvey PJ, Gilding EK, Tombling BJ, Chan LY, Kaas Q, Claridge-Chang A, Craik DJ. The acyclotide ribe 31 from Rinorea bengalensis has selective cytotoxicity and potent insecticidal properties in Drosophila. J Biol Chem 2022; 298:102413. [PMID: 36007611 PMCID: PMC9513267 DOI: 10.1016/j.jbc.2022.102413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 08/16/2022] [Accepted: 08/17/2022] [Indexed: 11/17/2022] Open
Abstract
Cyclotides and acyclic versions of cyclotides (acyclotides) are peptides involved in plant defense. These peptides contain a cystine knot motif formed by three interlocked disulfide bonds, with the main difference between the two classes being the presence or absence of a cyclic backbone, respectively. The insecticidal activity of cyclotides is well documented, but no study to date explores the insecticidal activity of acyclotides. Here, we present the first in vivo evaluation of the insecticidal activity of acyclotides from Rinorea bengalensis on the vinegar fly Drosophila melanogaster. Of a group of structurally comparable acyclotides, ribe 31 showed the most potent toxicity when fed to D. melanogaster. We screened a range of acyclotides and cyclotides and found their toxicity toward human red blood cells was substantially lower than toward insect cells, highlighting their selectivity and potential for use as bioinsecticides. Our confocal microscopy experiments indicated their cytotoxicity is likely mediated via membrane disruption. Furthermore, our surface plasmon resonance studies suggested ribe 31 preferentially binds to membranes containing phospholipids with phosphatidyl-ethanolamine headgroups. Despite having an acyclic backbone, we determined the three-dimensional NMR solution structure of ribe 31 is similar to that of cyclotides. In summary, our results suggest that, with further optimization, ribe 31 could have applications as an insecticide due to its potent in vivo activity against D. melanogaster. More broadly, this work advances the field by demonstrating that acyclotides are more common than previously thought, have potent insecticidal activity, and have the advantage of potentially being more easily manufactured than cyclotides.
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Affiliation(s)
- Tien T Dang
- 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
| | - Yen-Hua Huang
- 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
| | - Stanislav Ott
- Program in Neuroscience and Behavioral Disorders, Duke-NUS Medical School, Singapore, 169857
| | - 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
| | - 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, Queensland, 4072, Australia
| | - Benjamin J Tombling
- 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
| | - Lai Y Chan
- 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
| | - 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
| | - Adam Claridge-Chang
- Program in Neuroscience and Behavioral Disorders, Duke-NUS Medical School, Singapore, 169857; Institute for Molecular and Cell Biology, A*STAR, Singapore, 138673; Department of Physiology, National University of Singapore, Singapore, 117593
| | - 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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10
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Du Q, Huang YH, Wang CK, Kaas Q, Craik DJ. Mutagenesis of bracelet cyclotide hyen D reveals functionally and structurally critical residues for membrane binding and cytotoxicity. J Biol Chem 2022; 298:101822. [PMID: 35283188 PMCID: PMC9006653 DOI: 10.1016/j.jbc.2022.101822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 02/19/2022] [Accepted: 02/21/2022] [Indexed: 11/05/2022] Open
Abstract
Cyclotides have a wide range of bioactivities relevant for agricultural and pharmaceutical applications. This large family of naturally occurring macrocyclic peptides is divided into three subfamilies, with the bracelet subfamily being the largest and comprising the most potent cyclotides reported to date. However, attempts to harness the natural bioactivities of bracelet cyclotides and engineer-optimized analogs have been hindered by a lack of understanding of the structural and functional role of their constituent residues, which has been challenging because bracelet cyclotides are difficult to produce synthetically. We recently established a facile strategy to make the I11L mutant of cyclotide hyen D that is as active as the parent peptide, enabling the subsequent production of a series of variants. In the current study, we report an alanine mutagenesis structure-activity study of [I11L] hyen D to probe the role of individual residues on peptide folding using analytical chromatography, on molecular function using surface plasmon resonance, and on therapeutic potential using cytotoxicity assays. We found that Glu-6 and Thr-15 are critical for maintaining the structure of bracelet cyclotides and that hydrophobic residues in loops 2 and 3 are essential for membrane binding and cytotoxic activity, findings that are distinct from the structural and functional characteristics determined for other cyclotide subfamilies. In conclusion, this is the first report of a mutagenesis scan conducted on a bracelet cyclotide, offering insights into their function and supporting future efforts to engineer bracelet cyclotides for biotechnological applications.
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Affiliation(s)
- Qingdan Du
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, QLD, Australia
| | - Yen-Hua Huang
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, QLD, 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, QLD, Australia
| | - Quentin Kaas
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, QLD, 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, Australia.
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11
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Doffek B, Huang Y, Huang YH, Chan LY, Gilding EK, Jackson MA, Craik DJ. Comparative analysis of cyclotide-producing plant cell suspensions presents opportunities for cyclotide plant molecular farming. PHYTOCHEMISTRY 2022; 195:113053. [PMID: 34923360 DOI: 10.1016/j.phytochem.2021.113053] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/26/2021] [Accepted: 12/06/2021] [Indexed: 06/14/2023]
Abstract
Cyclotides are a class of ribosomally-synthesized plant peptides that function in plants as a defense against insects and fungal pathogens. Their unique structure comprises a cyclized peptide backbone threaded by three disulfide bonds, that imparts structural stability, a desirable quality for peptide-based therapeutics or insecticides. Producing these peptides synthetically is challenging due to the amount of chemical waste produced and inefficiency of folding certain cyclotides. Thus, it is desirable to develop a means to access cyclotide biosynthesis in their native hosts, cultured in defined conditions, at both laboratory and commercial scale. Here we developed suspension cell cultures from two species previously unexplored for cyclotide production in suspension cells, Clitoria ternatea L., Hybanthus enneaspermus F. Muell., as well as with Oldenlandia affinis (Roem. & Schult.) DC., a species reported previously to accumulate cyclotides in cell suspensions. We assessed the growth rate, cyclotide production and gene expression for the various species. We found that while many cyclotides had reduced expression in Oldenlandia affinis suspension cells when compared to plant organs, those in Clitoria ternatea and Hybanthus enneaspermus maintained or increased expression levels. The cyclotides that continued to be expressed in suspension cultures shared similar sequence and biophysical properties as a group, regardless of phylogenetic origin of the host. Of particular interest was the discovery of inducibility by NaCl of cyclotide expression in O. affinis, cycloviolacin O2 expression in O. affinis, and the scale up of cycloviolacin O2 production in H. enneaspermus. Together the results presented here highlight the utility of plant cell suspensions as modalities to produce macrocyclic peptides.
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Affiliation(s)
- Benjamin Doffek
- 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
| | - Yvonne Huang
- 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
| | - Yen-Hua Huang
- 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
| | - 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, 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, Queensland, 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, 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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12
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Gerlach SL, Dunlop RA, Metcalf JS, Banack SA, Cox PA. Cyclotides Chemosensitize Glioblastoma Cells to Temozolomide. JOURNAL OF NATURAL PRODUCTS 2022; 85:34-46. [PMID: 35044783 DOI: 10.1021/acs.jnatprod.1c00595] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Glioblastoma multiforme (GBM) is the most aggressive cancer originating in the brain, with a median survival of 12 months. Most patients do not respond to or develop resistance to the only effective chemotherapeutic drug, temozolomide (TMZ), used to treat gliomas. Novel treatment methods are critically needed. Cyclotides are plant peptides that may be promising adjuvants to TMZ chemotherapy. They exhibit antitumor activity and chemosensitize cells to doxorubicin in breast cancer studies. During this research, we optimized cyclotide isolation techniques, and several cyclotides (CyO2, CyO13, kalata B1, and varv peptide A) exhibited dose-dependent cytotoxicity in MTT assays with IC50 values of 2.15-7.92 μM against human brain astrocytoma cells (U-87 MG) and human bone marrow derived neuroblastoma cells (SH-SY5Y). CyO2 and varv peptide A increased TMZ-induced cell death in U-87 MG cultures alone and when coexposed with CyO2 or varv peptide A plus TMZ. Phase contrast microscopy of glioblastoma cells exposed to cyclotides alone and coexposed to TMZ indicated shrunken, granular cells with blebbing, and the most pronounced effects were observed with coexposure treatments of cyclotides and TMZ. Cumulative results provide the proof-of-concept that cyclotides may enhance TMZ chemotherapy, and in vivo pharmacokinetic investigations of cyclotides are warranted with respect to GBM.
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Affiliation(s)
- Samantha L Gerlach
- Department of Biology, Dillard University, New Orleans, Louisiana 70122, United States
| | - Rachael A Dunlop
- Institute for Ethnomedicine, Brain Chemistry Laboratories, Box 3464, Jackson, Wyoming 83001, United States
| | - James S Metcalf
- Institute for Ethnomedicine, Brain Chemistry Laboratories, Box 3464, Jackson, Wyoming 83001, United States
| | - Sandra A Banack
- Institute for Ethnomedicine, Brain Chemistry Laboratories, Box 3464, Jackson, Wyoming 83001, United States
| | - Paul Alan Cox
- Institute for Ethnomedicine, Brain Chemistry Laboratories, Box 3464, Jackson, Wyoming 83001, United States
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13
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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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14
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Huang YH, Du Q, Jiang Z, King GJ, Collins BM, Wang CK, Craik DJ. Enabling Efficient Folding and High-Resolution Crystallographic Analysis of Bracelet Cyclotides. Molecules 2021; 26:molecules26185554. [PMID: 34577034 PMCID: PMC8467136 DOI: 10.3390/molecules26185554] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 09/05/2021] [Accepted: 09/09/2021] [Indexed: 11/23/2022] Open
Abstract
Cyclotides have attracted great interest as drug design scaffolds because of their unique cyclic cystine knotted topology. They are classified into three subfamilies, among which the bracelet subfamily represents the majority and comprises the most bioactive cyclotides, but are the most poorly utilized in drug design applications. A long-standing challenge has been the very low in vitro folding yields of bracelets, hampering efforts to characterize their structures and activities. Herein, we report substantial increases in bracelet folding yields enabled by a single point mutation of residue Ile-11 to Leu or Gly. We applied this discovery to synthesize mirror image enantiomers and used quasi-racemic crystallography to elucidate the first crystal structures of bracelet cyclotides. This study provides a facile strategy to produce bracelet cyclotides, leading to a general method to easily access their atomic resolution structures and providing a basis for development of biotechnological applications.
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Affiliation(s)
- Yen-Hua Huang
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia; (Y.-H.H.); (Q.D.); (Z.J.); (B.M.C.); (C.K.W.)
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Qingdan Du
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia; (Y.-H.H.); (Q.D.); (Z.J.); (B.M.C.); (C.K.W.)
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Zhihao Jiang
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia; (Y.-H.H.); (Q.D.); (Z.J.); (B.M.C.); (C.K.W.)
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Gordon J. King
- The Centre for Microscopy and Microanalysis, The University of Queensland, Brisbane, QLD 4072, Australia;
| | - Brett M. Collins
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia; (Y.-H.H.); (Q.D.); (Z.J.); (B.M.C.); (C.K.W.)
| | - Conan K. Wang
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia; (Y.-H.H.); (Q.D.); (Z.J.); (B.M.C.); (C.K.W.)
- 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, The University of Queensland, Brisbane, QLD 4072, Australia; (Y.-H.H.); (Q.D.); (Z.J.); (B.M.C.); (C.K.W.)
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, QLD 4072, Australia
- Correspondence: ; Tel.: +61-7-3346-2019
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15
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Gattringer J, Ndogo OE, Retzl B, Ebermann C, Gruber CW, Hellinger R. Cyclotides Isolated From Violet Plants of Cameroon Are Inhibitors of Human Prolyl Oligopeptidase. Front Pharmacol 2021; 12:707596. [PMID: 34322026 PMCID: PMC8311463 DOI: 10.3389/fphar.2021.707596] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 06/28/2021] [Indexed: 11/13/2022] Open
Abstract
Traditional medicine and the use of herbal remedies are well established in the African health care system. For instance, Violaceae plants are used for antimicrobial or anti-inflammatory applications in folk medicine. This study describes the phytochemical analysis and bioactivity screening of four species of the violet tribe Allexis found in Cameroon. Allexis cauliflora, Allexis obanensis, Allexis batangae and Allexis zygomorpha were evaluated for the expression of circular peptides (cyclotides) by mass spectrometry. The unique cyclic cystine-rich motif was identified in several peptides of all four species. Knowing that members of this peptide family are protease inhibitors, the plant extracts were evaluated for the inhibition of human prolyl oligopeptidase (POP). Since all four species inhibited POP activity, a bioactivity-guided fractionation approach was performed to isolate peptide inhibitors. These novel cyclotides, alca 1 and alca 2 exhibited IC50 values of 8.5 and 4.4 µM, respectively. To obtain their amino acid sequence information, combinatorial enzymatic proteolysis was performed. The proteolytic fragments were evaluated in MS/MS fragmentation experiments and the full-length amino acid sequences were obtained by de novo annotation of fragment ions. In summary, this study identified inhibitors of the human protease POP, which is a drug target for inflammatory or neurodegenerative disorders.
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Affiliation(s)
- Jasmin Gattringer
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Olivier Eteme Ndogo
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Bernhard Retzl
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Carina Ebermann
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Christian W Gruber
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Roland Hellinger
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
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16
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Plant derived cyclic peptides. Biochem Soc Trans 2021; 49:1279-1285. [PMID: 34156400 PMCID: PMC8286818 DOI: 10.1042/bst20200881] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 06/02/2021] [Accepted: 06/04/2021] [Indexed: 12/19/2022]
Abstract
Cyclic peptides are widespread throughout the plant kingdom, and display diverse sequences, structures and bioactivities. The potential applications attributed to these peptides and their unusual biosynthesis has captivated the attention of researchers for many years. Several gene sequences for plant cyclic peptides have been discovered over the last two decades but it is only recently that we are beginning to understand the intricacies associated with their biosynthesis. Recent studies have focussed on three main classes of plant derived cyclic peptides, namely orbitides, SFTI related peptides and cyclotides. In this mini-review, we discuss the expansion of the known sequence and structural diversity in these families, insights into the enzymes involved in the biosynthesis, the exciting applications which includes a cyclotide currently in clinical trials for the treatment of multiple sclerosis, and new production methods that are being developed to realise the potential of plant cyclic peptides as pharmaceutical or agricultural agents.
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17
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van den Broek K, Epple M, Kersten LS, Kuhn H, Zielesny A. Quantitative Estimation of Cyclotide-Induced Bilayer Membrane Disruption by Lipid Extraction with Mesoscopic Simulation. J Chem Inf Model 2021; 61:3027-3040. [PMID: 34008405 DOI: 10.1021/acs.jcim.1c00332] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cyclotide-induced membrane disruption is studied at the microsecond timescale by dissipative particle dynamics to quantitatively estimate a kinetic rate constant for membrane lipid extraction with a ″sandwich″ interaction model where two bilayer membranes enclose a cyclotide/water compartment. The obtained bioactivity trends for cyclotides Kalata B1, Cycloviolacin O2, and selected mutants with different membrane types are in agreement with experimental findings: For all membranes investigated, Cycloviolacin O2 shows a higher lipid extraction activity than Kalata B1. The presence of cholesterol leads to a decreased cyclotide activity compared to cholesterol-free membranes. Phosphoethanolamine-rich membranes exhibit an increased membrane disruption. A cyclotide's ″hydrophobic patch″ surface area is important for its bioactivity. A replacement of or with charged amino acid residues may lead to super-mutants with above-native activity but without simple charge-activity patterns. Cyclotide mixtures show linearly additive bioactivities without significant sub- or over-additive effects. The proposed method can be applied as a fast and easy-to-use tool for exploring structure-activity relationships of cyclotide/membrane systems: With the open software provided, the rate constant of a single cyclotide/membrane system can be determined in about 1 day by a scientific end-user without programming skills.
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Affiliation(s)
- Karina van den Broek
- Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, 45141 Essen, Germany.,Institute for Bioinformatics and Chemoinformatics, Westphalian University of Applied Sciences, 45665 Recklinghausen, Germany
| | - Matthias Epple
- Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, 45141 Essen, Germany
| | - Lisa Sophie Kersten
- Institute for Bioinformatics and Chemoinformatics, Westphalian University of Applied Sciences, 45665 Recklinghausen, Germany
| | - Hubert Kuhn
- CAM-D Technologies GmbH, 42697 Solingen, Germany
| | - Achim Zielesny
- Institute for Bioinformatics and Chemoinformatics, Westphalian University of Applied Sciences, 45665 Recklinghausen, Germany
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18
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Dang TT, Chan LY, Tombling BJ, Harvey PJ, Gilding EK, Craik DJ. In Planta Discovery and Chemical Synthesis of Bracelet Cystine Knot Peptides from Rinorea bengalensis. JOURNAL OF NATURAL PRODUCTS 2021; 84:395-407. [PMID: 33570395 DOI: 10.1021/acs.jnatprod.0c01065] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Cyclotides are plant-derived peptides that have attracted interest as biocides and scaffolds for the development of stable peptide therapeutics. Cyclotides are characterized by their cyclic backbone and cystine knot framework, which engenders them with remarkably high stability. This study reports the cystine knot-related peptidome of Rinorea bengalensis, a small rainforest tree in the Violaceae family that is distributed from Australia westward to India. Surprisingly, many more acyclic knotted peptides (acyclotides) were discovered than cyclic counterparts (cyclotides), with 32 acyclotides and 1 cyclotide sequenced using combined transcriptome and proteomic analyses. Nine acyclotides were isolated and screened against a panel of mammalian cell lines, showing they had the cytotoxic properties normally associated with cyclotide-like peptides. NMR analysis of the acyclotide ribes 21 and 22 and the cyclotide ribe 33 confirmed that these peptides contained the cystine knot structural motif. The bracelet-subfamily cyclotide ribe 33 was amenable to chemical synthesis in reasonable yield, an achievement that has long eluded previous attempts to synthetically produce bracelet cyclotides. Accordingly, ribe 33 represents an exciting new bracelet cyclotide scaffold that can be subject to chemical modification for future molecular engineering applications.
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Affiliation(s)
- Tien T Dang
- 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
| | - Lai Y Chan
- 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
| | - Benjamin J Tombling
- 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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19
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Du Q, Huang YH, Bajpai A, Frosig-Jorgensen M, Zhao G, Craik DJ. Evaluation of the in Vivo Aphrodisiac Activity of a Cyclotide Extract from Hybanthus enneaspermus. JOURNAL OF NATURAL PRODUCTS 2020; 83:3736-3743. [PMID: 33296204 DOI: 10.1021/acs.jnatprod.0c01045] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Hybanthus enneaspermus is an Indian folk medicinal herb that has been widely used as a libido enhancer. This plant belongs to the Violaceae plant family, which ubiquitously contains disulfide-rich cyclic peptides named cyclotides. Cyclotides are an expanding plant-derived peptide family with numerous interesting bioactivities, and their unusual stability against proteolysis has attracted much attention in drug design applications. Recently, H. enneaspermus has been reported to be a rich source of cyclotides, and hence, it was of interest to investigate whether cyclotides contribute to its aphrodisiac activity. In this study, we evaluated the in vivo aphrodisiac activity of the herbal powder, extract, and the most abundant cyclotide, hyen D, extracted from H. enneaspermus on rats in a single dose regimen. After dosing, the sexual behaviors of male rats were observed, recorded, analyzed, and compared with those of the vehicle group. The results show that the extract and hyen D significantly decreased the intromission latency of sexually naïve male rats and the extract improved a range of other measured sexual parameters. The results suggest that the extract could enhance libido as well as facilitate erectile function in male rats and that the cyclotide hyen D could contribute to the libido-enhancing activity of this ethnomedicinal herb.
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Affiliation(s)
- Qingdan Du
- 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
| | - Yen-Hua Huang
- 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
| | - Abhishek Bajpai
- 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
| | - Majbrit Frosig-Jorgensen
- 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
| | - Guangzu Zhao
- 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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