1
|
Zhang X, Chen R, Shu H, Liang P, Qin T, Wang K, Guo A, Craik DJ, Liao B, Zhang J. Gene-guided identifications of a structure-chimeric cyclotide viphi I from Viola philippica: Potential functions against cadmium and nematodes. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 347:112185. [PMID: 38986912 DOI: 10.1016/j.plantsci.2024.112185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 07/04/2024] [Accepted: 07/06/2024] [Indexed: 07/12/2024]
Abstract
The cyclic peptides, cyclotides, are identified mostly with 29-31-aa (amino acid residues) but rarely with ≥ 34-aa in plants. Viola philippica is a well-known medicinal plant but a rare metallophyte with cyclotides. A hypothesis was hence raised that the potential novel 34-aa cyclotide of Viola philippica would clearly broaden the structural and functional diversities of plant cyclotides. After homology-cloning the cyclotide precursor gene of VpCP5, a 34-aa cyclotide (viphi I) was identified to be larger than 22 other known cyclotides in V. philippica. It had a chimeric primary structure, due to its unusual loop structures (8 residues in loop 2 and 6 residues in loop 5) and aa composition (3 E and 5 R), by using phylogenetic analyses and an in-house cyclotide analysis tool, CyExcel_V1. A plasmid pCYC-viphi_I and a lab-used recombinant process were specially constructed for preparing viphi I. Typically, 0.12 or 0.25 mg ml-1 co-exposed viphi I could significantly remain cell activities with elevating Cd2+-exposed doses from 10-8 to 10-6 mol l-1 in MCF7 cells. In the model nematode Caenorhabditis elegans, IC50 values of viphi I to inhibit adult ratios and to induce death ratios, were 184.7 and 585.9 µg ml-1, respectively; the median lifespan of adult worms decreased from 14 to 2 d at viphi I doses ranging from 0.05 to 2 mg ml-1. Taken together, the newly identified viphi I exhibits functional potentials against cadmium and nematodes, providing new insights into structural and functional diversity of chimeric cyclotides in plants.
Collapse
Affiliation(s)
- Xiaojie Zhang
- Guangdong Pharmaceutical University, School of Life Sciences and Biopharmaceutics, Guangzhou 510006, China.
| | - Ruohong Chen
- Sun Yat-sen University, School of Life Sciences, Guangzhou 510275, China.
| | - Haoyue Shu
- Sun Yat-sen University, School of Life Sciences, Guangzhou 510275, China.
| | - Peihui Liang
- Guangdong Pharmaceutical University, School of Life Sciences and Biopharmaceutics, Guangzhou 510006, China.
| | - Ting Qin
- Guangdong Pharmaceutical University, School of Life Sciences and Biopharmaceutics, Guangzhou 510006, China.
| | - Kemei Wang
- Guangdong Pharmaceutical University, School of Life Sciences and Biopharmaceutics, Guangzhou 510006, China.
| | - Aimin Guo
- Guangdong Pharmaceutical University, School of Life Sciences and Biopharmaceutics, Guangzhou 510006, China.
| | - David J Craik
- The University of Queensland, Institute for Molecular Bioscience, Brisbane, QLD 4072, Australia.
| | - Bin Liao
- Sun Yat-sen University, School of Life Sciences, Guangzhou 510275, China.
| | - Jun Zhang
- Guangdong Pharmaceutical University, School of Life Sciences and Biopharmaceutics, Guangzhou 510006, China.
| |
Collapse
|
2
|
Badaczewska-Dawid A, Wróblewski K, Kurcinski M, Kmiecik S. Structure prediction of linear and cyclic peptides using CABS-flex. Brief Bioinform 2024; 25:bbae003. [PMID: 38305457 PMCID: PMC10836054 DOI: 10.1093/bib/bbae003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 12/08/2023] [Accepted: 12/28/2023] [Indexed: 02/03/2024] Open
Abstract
The structural modeling of peptides can be a useful aid in the discovery of new drugs and a deeper understanding of the molecular mechanisms of life. Here we present a novel multiscale protocol for the structure prediction of linear and cyclic peptides. The protocol combines two main stages: coarse-grained simulations using the CABS-flex standalone package and an all-atom reconstruction-optimization process using the Modeller program. We evaluated the protocol on a set of linear peptides and two sets of cyclic peptides, with cyclization through the backbone and disulfide bonds. A comparison with other state-of-the-art tools (APPTEST, PEP-FOLD, ESMFold and AlphaFold implementation in ColabFold) shows that for most cases, AlphaFold offers the highest resolution. However, CABS-flex is competitive, particularly when it comes to short linear peptides. As demonstrated, the protocol performance can be further improved by combination with the residue-residue contact prediction method or more efficient scoring. The protocol is included in the CABS-flex standalone package along with online documentation to aid users in predicting the structure of peptides and mini-proteins.
Collapse
Affiliation(s)
| | - Karol Wróblewski
- Biological and Chemical Research Center, Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
| | - Mateusz Kurcinski
- Biological and Chemical Research Center, Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
| | - Sebastian Kmiecik
- Biological and Chemical Research Center, Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
| |
Collapse
|
3
|
Tyler TJ, Durek T, Craik DJ. Native and Engineered Cyclic Disulfide-Rich Peptides as Drug Leads. Molecules 2023; 28:molecules28073189. [PMID: 37049950 PMCID: PMC10096437 DOI: 10.3390/molecules28073189] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 03/27/2023] [Accepted: 03/29/2023] [Indexed: 04/07/2023] Open
Abstract
Bioactive peptides are a highly abundant and diverse group of molecules that exhibit a wide range of structural and functional variation. Despite their immense therapeutic potential, bioactive peptides have been traditionally perceived as poor drug candidates, largely due to intrinsic shortcomings that reflect their endogenous heritage, i.e., short biological half-lives and poor cell permeability. In this review, we examine the utility of molecular engineering to insert bioactive sequences into constrained scaffolds with desired pharmaceutical properties. Applying lessons learnt from nature, we focus on molecular grafting of cyclic disulfide-rich scaffolds (naturally derived or engineered), shown to be intrinsically stable and amenable to sequence modifications, and their utility as privileged frameworks in drug design.
Collapse
Affiliation(s)
- Tristan J. Tyler
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Thomas Durek
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
- 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
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, QLD 4072, Australia
| |
Collapse
|
4
|
Salah A, El-Khateeb EA, Gaafar RM, Mohamed Atia MA. Genome-wide in silico and in vitro mining to develop a novel cyclotide-based marker system in plants. BIOTECHNOL BIOTEC EQ 2023. [DOI: 10.1080/13102818.2023.2176175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023] Open
Affiliation(s)
- Arwa Salah
- Genome Mapping Department, Agricultural Genetic Engineering Research Institute (AGERI), Agricultural Research Center (ARC), Giza, Egypt
| | | | | | - Mohamed Atia Mohamed Atia
- Genome Mapping Department, Agricultural Genetic Engineering Research Institute (AGERI), Agricultural Research Center (ARC), Giza, Egypt
| |
Collapse
|
5
|
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.
Collapse
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.
| |
Collapse
|
6
|
Kawish M, Jabri T, Elhissi A, Zahid H, Muhammad Iqbal K, Rao K, Gul J, Abdullah M, Shah MR. Galactosylated iron oxide nanoparticles for enhancing oral bioavailability of ceftriaxone. Pharm Dev Technol 2021; 26:291-301. [PMID: 33475034 DOI: 10.1080/10837450.2020.1866602] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The current study focuses on the development, characterization, biocompatibility investigation and oral bioavailability evaluation of ceftriaxone (CFT)-loaded lactobionic acid (LBA)-functionalized iron oxide magnetic nanoparticles (MNP-LBA). Atomic force microscopy and dynamic light scattering showed that the developed CFT-loaded MNP-LBA is spherical, with a measured hydrodynamic size of 147 ± 15.9 nm and negative zeta potential values (-35 ± 0.58 mV). Fourier transformed infrared analysis revealed interactions between the nanocarrier and the drug. Nanoparticles showed high drug entrapment efficiencies of 91.5 ± 2.2%, and the drug was released gradually in vitro and shows prolonged in vitro stability using simulated gastrointestinal (GI) fluids. The formulations were found to be highly biocompatible (up to 100 µg/mL) and hemocompatible (up to 1.0 mg/mL). Using an albino rabbit model, the formulation showed a significant enhancement in drug plasma concentration up to 14.46 ± 2.5 µg/mL in comparison with its control (1.96 ± 0.58 µg/mL). Overall, the developed MNP-LBA formulation was found promising for provision of high-drug entrapment, gradual drug release and was appropriate for enhancing the oral delivery of CFT.
Collapse
Affiliation(s)
- Muhammad Kawish
- International Center for Chemical and Biological Sciences, H.E.J Research Institute of Chemistry, University of Karachi, Karachi, Pakistan
| | - Tooba Jabri
- International Center for Chemical and Biological Sciences, H.E.J Research Institute of Chemistry, University of Karachi, Karachi, Pakistan
| | - Abdelbary Elhissi
- College of Pharmacy, QU Health, Qatar University, Doha, Qatar.,Office of The Vice President for Research and Graduate Studies, Qatar University, Doha, Qatar
| | - Hina Zahid
- Faculty of Pharmaceutical Sciences, Dow University of Health Sciences Karachi, Karachi, Pakistan
| | - Kanwal Muhammad Iqbal
- International Center for Chemical and Biological Sciences, H.E.J Research Institute of Chemistry, University of Karachi, Karachi, Pakistan
| | - Komal Rao
- International Center for Chemical and Biological Sciences, H.E.J Research Institute of Chemistry, University of Karachi, Karachi, Pakistan
| | - Jasra Gul
- International Center for Chemical and Biological Sciences, H.E.J Research Institute of Chemistry, University of Karachi, Karachi, Pakistan
| | - Muhammad Abdullah
- International Center for Chemical and Biological Sciences, H.E.J Research Institute of Chemistry, University of Karachi, Karachi, Pakistan
| | - Muhammad Raza Shah
- International Center for Chemical and Biological Sciences, H.E.J Research Institute of Chemistry, University of Karachi, Karachi, Pakistan
| |
Collapse
|
7
|
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.
Collapse
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.
| |
Collapse
|
8
|
Wang CK, Amiss AS, Weidmann J, Craik DJ. Structure-activity analysis of truncated albumin-binding domains suggests new lead constructs for potential therapeutic delivery. J Biol Chem 2020; 295:12143-12152. [PMID: 32647013 PMCID: PMC7443490 DOI: 10.1074/jbc.ra120.014168] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 07/09/2020] [Indexed: 12/13/2022] Open
Abstract
Rapid clearance by renal filtration is a major impediment to the translation of small bioactive biologics into drugs. To extend serum t1/2, a commonly used approach is to attach drug leads to the G-related albumin-binding domain (ABD) to bind albumin and evade clearance. Despite the success of this approach in extending half-lives of a wide range of biologics, it is unclear whether the existing constructs are optimized for binding and size; any improvements along these lines could lead to improved drugs. Characterization of the biophysics of binding of an ABD to albumin in solution could shed light on this question. Here, we examine the binding of an ABD to human serum albumin using isothermal titration calorimetry and assess the structural integrity of the ABD using CD, NMR, and molecular dynamics. A structure-activity analysis of truncations of the ABD suggests that downsized variants could replace the full-length domain. Reducing size could have the benefit of reducing potential immunogenicity problems. We further showed that one of these variants could be used to design a bifunctional molecule with affinity for albumin and a serum protein involved in cholesterol metabolism, PCSK9, demonstrating the potential utility of these fragments in the design of cholesterol-lowering drugs. Future work could extend these in vitro binding studies to other ABD variants to develop therapeutics. Our study presents new understanding of the solution structural and binding properties of ABDs, which has implications for the design of next-generation long-lasting therapeutics.
Collapse
Affiliation(s)
- Conan K. Wang
- Institute for Molecular Bioscience and Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland, Australia
| | - Anna S. Amiss
- Institute for Molecular Bioscience and Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland, Australia
| | - Joachim Weidmann
- Institute for Molecular Bioscience and Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland, Australia
| | - David J. Craik
- Institute for Molecular Bioscience and Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland, Australia
| |
Collapse
|
9
|
Du Q, Chan LY, Gilding EK, Henriques ST, Condon ND, Ravipati AS, Kaas Q, Huang YH, Craik DJ. Discovery and mechanistic studies of cytotoxic cyclotides from the medicinal herb Hybanthus enneaspermus. J Biol Chem 2020; 295:10911-10925. [PMID: 32414842 DOI: 10.1074/jbc.ra120.012627] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 05/08/2020] [Indexed: 12/12/2022] Open
Abstract
Cyclotides are plant-derived peptides characterized by an ∼30-amino acid-long cyclic backbone and a cystine knot motif. Cyclotides have diverse bioactivities, and their cytotoxicity has attracted significant attention for its potential anticancer applications. Hybanthus enneaspermus (Linn) F. Muell is a medicinal herb widely used in India as a libido enhancer, and a previous study has reported that it may contain cyclotides. In the current study, we isolated 11 novel cyclotides and 1 known cyclotide (cycloviolacin O2) from H. enneaspermus and used tandem MS to determine their amino acid sequences. We found that among these cyclotides, hyen C comprises a unique sequence in loops 1, 2, 3, 4, and 6 compared with known cyclotides. The most abundant cyclotide in this plant, hyen D, had anticancer activity comparable to that of cycloviolacin O2, one of the most cytotoxic known cyclotides. We also provide mechanistic insights into how these novel cyclotides interact with and permeabilize cell membranes. Results from surface plasmon resonance experiments revealed that hyen D, E, L, and M and cycloviolacin O2 preferentially interact with model lipid membranes that contain phospholipids with phosphatidyl-ethanolamine headgroups. The results of a lactate dehydrogenase assay indicated that exposure to these cyclotides compromises cell membrane integrity. Using live-cell imaging, we show that hyen D induces rapid membrane blebbing and cell necrosis. Cyclotide-membrane interactions correlated with the observed cytotoxicity, suggesting that membrane permeabilization and disintegration underpin cyclotide cytotoxicity. These findings broaden our knowledge on the indigenous Indian herb H. enneaspermus and have uncovered cyclotides with potential anticancer activity.
Collapse
Affiliation(s)
- Qingdan Du
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Lai Y Chan
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Edward K Gilding
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Sónia Troeira Henriques
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia.,School of Biomedical Sciences, Institute of Health & Biomedical Innovation and Translational Research Institute, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Nicholas D Condon
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Anjaneya S Ravipati
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Quentin Kaas
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Yen-Hua Huang
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - David J Craik
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| |
Collapse
|
10
|
Tammineni R, Gulati P, Kumar S, Mohanty A. An overview of acyclotides: Past, present and future. PHYTOCHEMISTRY 2020; 170:112215. [PMID: 31812106 DOI: 10.1016/j.phytochem.2019.112215] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Revised: 11/19/2019] [Accepted: 11/20/2019] [Indexed: 06/10/2023]
Abstract
Acyclotides are plant-based, acyclic miniproteins with cystine knot motif formed by three conserved disulfide linkages and lack head to tail ligation. Acyclotides may not necessarily be less stable, even though they lack cyclic backbone, as the conserved cystine knot feature provides the required stability. Violacin A was the first acyclotide, isolated from Viola odorata in 2006. Until now, acyclotides have been reported from five dicot families (Violaceae, Rubiaceae, Cucurbitaceae, Solanaceae, Fabaceae) and one monocot family (Poaceae). In Poaceae, only acyclotides have been found whereas in dicot families both cyclotides and acyclotides have been isolated. In last 15 years, several acyclotides with antimicrobial, cytotoxic and hemolytic bioactivities have been discovered. Thus, although many naturally expressed acyclotides do exhibit bioactivities, the linearization of the cyclic peptides may result in loss of bioactivities. Although, bioactivities of acyclotides are comparable to their cyclic counterparts, the numbers of isolated acyclotides are still few. Further, those discovered, have the scope to be screened for agriculturally important activities (insecticidal, anti-helminthic, molluscicidal) and pharmaceutical properties (anticancer, anti-HIV, immuno-stimulant). The feasibility of application of acyclotides is because of their relatively less complex biological synthesis compared to cyclotides, as the cyclization step is not needed. This attribute facilitates the production of transgenic crops and/or its expression in heterologous organisms, lacking cyclization machinery. Keeping in view the bioactivities and the wide array of emerging potential applications of acyclotides, the present review discusses their distribution in plants, gene and protein structure, biosynthesis, bioactivities and mechanism of action. Further, their potential applications and future perspectives to exploit them in agriculture and pharmaceutical industries have been highlighted.
Collapse
Affiliation(s)
- Ramya Tammineni
- Bioinformatics Infrastructure Facility, Gargi College, University of Delhi, India
| | - Pooja Gulati
- Department of Microbiology, Maharshi Dayanand University, Rohtak, Haryana, India
| | - Sanjay Kumar
- Department of Microbiology, Maharshi Dayanand University, Rohtak, Haryana, India
| | | |
Collapse
|
11
|
Kan MW, Craik DJ. Discovery of Cyclotides from Australasian Plants. Aust J Chem 2020. [DOI: 10.1071/ch19658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This article is part of a special issue celebrating the contributions of Professor Paul Alewood to peptide science. We begin by providing a summary of collaborative projects between the Alewood and Craik groups at The University of Queensland and highlighting the impacts of some of these studies. In particular, studies on the discovery, synthesis, structures, and bioactivities of disulfide-rich toxins from animal venoms have led to a greater understanding of the biology of ion channels and to applications of these bioactive peptides in drug design. The second part of the article focuses on plant-derived disulfide-rich cyclic peptides, known as cyclotides, and includes an analysis of the geographical distribution of Australasian plant species that contain cyclotides as well as an analysis of the diversity of cyclotide sequences found in Australasian plants. This should provide a useful resource for researchers to access native cyclotides and explore their chemistry and biology.
Collapse
|
12
|
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.
Collapse
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
| |
Collapse
|
13
|
Finkina EI, Melnikova DN, Bogdanov IV, Ovchinnikova TV. Peptides of the Innate Immune System of Plants. Part I. Structure, Biological Activity, and Mechanisms of Action. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2019. [DOI: 10.1134/s1068162019010060] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
14
|
Niyomploy P, Chan LY, Harvey PJ, Poth AG, Colgrave ML, Craik DJ. Discovery and Characterization of Cyclotides from Rinorea Species. JOURNAL OF NATURAL PRODUCTS 2018; 81:2512-2520. [PMID: 30387611 DOI: 10.1021/acs.jnatprod.8b00572] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Cyclotides are macrocyclic cystine-knotted peptides most commonly found in the Violaceae plant family. Although Rinorea is the second-largest genera within the Violaceae family, few studies have examined whether or not they contain cyclotides. To further our understanding of cyclotide diversity and evolution, we examined the cyclotide content of two Rinorea species found in Southeast Asia: R. virgata and R. bengalensis. Seven cyclotides were isolated from R. virgata (named Rivi1-7), and a known cyclotide (cT10) was found in R. bengalensis. Loops 2, 5, and 6 of Rivi1-4 contained sequences not previously seen in corresponding loops of known cyclotides, thereby expanding our understanding of the diversity of cyclotides. In addition, the sequence of loop 2 of Rivi3 and Rivi4 were identical to some related noncyclic "acyclotides" from the Poaceae plant family. As only acyclotides, but not cyclotides, have been reported in monocotyledons thus far, our findings support an evolutionary link between monocotyledon-derived ancestral cyclotide precursors and dicotyledon-derived cyclotides. Furthermore, Rivi2 and Rivi3 had comparable cytotoxic activities to the most cytotoxic cyclotide known to date: cycloviolacin O2 from Viola odorata; yet, unlike cycloviolacin O2, they did not show hemolytic activity. Therefore, these cyclotides represent novel scaffolds for use in future anticancer drug design.
Collapse
Affiliation(s)
- Ploypat Niyomploy
- Institute for Molecular Bioscience , The University of Queensland , Brisbane , Queensland 4072 , Australia
- Department of Chemistry, Faculty of Science , Chulalongkorn University , Bangkok 10330 , Thailand
| | - Lai Yue Chan
- Institute for Molecular Bioscience , The University of Queensland , Brisbane , Queensland 4072 , Australia
| | - Peta J Harvey
- Institute for Molecular Bioscience , The University of Queensland , Brisbane , Queensland 4072 , Australia
| | - Aaron G Poth
- Institute for Molecular Bioscience , The University of Queensland , Brisbane , Queensland 4072 , Australia
| | - Michelle L Colgrave
- CSIRO Agriculture and Food , 306 Carmody Road , St. Lucia , Queensland 4067 , Australia
- School of Science , Edith Cowan University , 270 Joondalup Drive , Joondalup , WA 6027 , Australia
| | - David J Craik
- Institute for Molecular Bioscience , The University of Queensland , Brisbane , Queensland 4072 , Australia
| |
Collapse
|
15
|
Zhang RY, Thapa P, Espiritu MJ, Menon V, Bingham JP. From nature to creation: Going around in circles, the art of peptide cyclization. Bioorg Med Chem 2018; 26:1135-1150. [DOI: 10.1016/j.bmc.2017.11.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 11/06/2017] [Accepted: 11/09/2017] [Indexed: 02/02/2023]
|
16
|
Narayani M, Chadha A, Srivastava S. Cyclotides from the Indian Medicinal Plant Viola odorata (Banafsha): Identification and Characterization. JOURNAL OF NATURAL PRODUCTS 2017; 80:1972-1980. [PMID: 28621949 DOI: 10.1021/acs.jnatprod.6b01004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Cyclotides are cyclic cystine knotted macrocyclic plant peptides that have several promising applications. This study was undertaken to detect and identify known and new cyclotides in Viola odorata, a commercially important medicinal plant, from three geographical locations in India. The number of cyclotides in the plant varied with the tissue (leaves, petioles, flowers, runners, and roots) and with geographical locations in India. Using liquid chromatography coupled to Fourier transform mass spectrometry (FTMS), 166 cyclotide-like masses were observed to display cyclotide-diagnostic mass shifts following reduction, alkylation, and digestion, and 71 of these were positively identified based on automated spectrum matching. Of the remaining 95 putative cyclotides observed, de novo peptide sequencing of three new cyclotides, namely, vodo I1 (1), vodo I2 (2), and vodo I3 (3), was carried out with tandem mass spectrometry.
Collapse
Affiliation(s)
- M Narayani
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras , Chennai 600036, India
| | - Anju Chadha
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras , Chennai 600036, India
| | - Smita Srivastava
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras , Chennai 600036, India
| |
Collapse
|
17
|
Ravipati AS, Poth AG, Troeira Henriques S, Bhandari M, Huang YH, Nino J, Colgrave ML, Craik DJ. Understanding the Diversity and Distribution of Cyclotides from Plants of Varied Genetic Origin. JOURNAL OF NATURAL PRODUCTS 2017; 80:1522-1530. [PMID: 28471681 DOI: 10.1021/acs.jnatprod.7b00061] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Cyclotides are a large family of naturally occurring plant-derived macrocyclic cystine-knot peptides, with more than 400 having been identified in species from the Violaceae, Rubiaceae, Cucurbitaceae, Fabaceae, and Solanaceae families. Nevertheless, their specialized distribution within the plant kingdom remains poorly understood. In this study, the diversity of cyclotides was explored through the screening of 197 plants belonging to 43 different families. In total, 28 cyclotides were sequenced from 15 plant species, one of which belonged to the Rubiaceae and 14 to the Violaceae. Every Violaceae species screened contained cyclotides, but they were only sparsely represented in Rubiaceae and nonexistent in other families. The study thus supports the hypothesis that cyclotides are ubiquitous in the Violaceae, and it adds to the list of plants found to express kalata S and cycloviolacin O12. Finally, previous studies suggested the existence of cyclotide isoforms with either an Asn or an Asp at the C-terminal processing site of the cyclotide domain within the precursor proteins. Here we found that despite the discovery of a few cyclotides genuinely containing an Asp in loop 6 as evidenced by gene sequencing, deamidation of Asn during enzymatic digestion resulted in the artifactual presence of Asp isoforms. This result is consistent with studies suggesting that peptides can undergo deamidation after being subjected to external factors, including pH, temperature, and enzymatic digestion.
Collapse
Affiliation(s)
- Anjaneya S Ravipati
- Institute for Molecular Bioscience, The University of Queensland , Brisbane 4072, Queensland Australia
| | - Aaron G Poth
- Institute for Molecular Bioscience, The University of Queensland , Brisbane 4072, Queensland Australia
| | - Sónia Troeira Henriques
- Institute for Molecular Bioscience, The University of Queensland , Brisbane 4072, Queensland Australia
| | - Murari Bhandari
- Institute for Molecular Bioscience, The University of Queensland , Brisbane 4072, Queensland Australia
| | - Yen-Hua Huang
- Institute for Molecular Bioscience, The University of Queensland , Brisbane 4072, Queensland Australia
| | - Jaime Nino
- Universidad Tecnológica de Pereira , Cra 27 No 10-02-Los Álamos, Pereira, Risaralda, Colombia
| | - Michelle L Colgrave
- Commonwealth Scientific and Industrial Research Organization, Agriculture and Food, St Lucia 4067, Queensland, Australia
| | - David J Craik
- Institute for Molecular Bioscience, The University of Queensland , Brisbane 4072, Queensland Australia
| |
Collapse
|
18
|
Daly NL, Gunasekera S, Clark RJ, Lin F, Wade JD, Anderson MA, Craik DJ. The N-terminal pro-domain of the kalata B1 cyclotide precursor is intrinsically unstructured. Biopolymers 2017; 106:825-833. [PMID: 27564841 DOI: 10.1002/bip.22977] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 08/23/2016] [Accepted: 08/25/2016] [Indexed: 11/09/2022]
Abstract
Cyclotides are plant-derived, gene-encoded, circular peptides with a range of host-defense functions, including insecticidal activity. They also have potential as pharmaceutical scaffolds and understanding their biosynthesis is important to facilitate their large-scale production. Insights into the biosynthesis of cyclotides are emerging but there are still open questions, particularly regarding the influence of the structure of the precursor proteins on processing/biosynthetic pathways. The precursor protein of kalata B1, encoded by the plant Oldenlandia affinis, contains N- and C-terminal propeptides that flank the mature cyclotide domain. The C-terminal region (ctr) is important for the cyclization process, whereas the N-terminal repeat (ntr) has been implicated in vacuolar targeting. In this study we examined the structure and folding of various truncated constructs of the ntr coupled to the mature domain of kalata B1. Despite the ntr having a well-defined helical structure in isolation, once coupled to the natively folded mature domain there is no evidence of an ordered structure. Surprisingly, the ntr appears to be highly disordered and induces self-association of the precursor. This self-association might be associated with the role of the ntr as a vacuolar-targeting signal, as previously shown for unrelated storage proteins.
Collapse
Affiliation(s)
- Norelle L Daly
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Sunithi Gunasekera
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Richard J Clark
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Feng Lin
- Howard Florey Institute, University of Melbourne, Victoria, 3010, Australia
| | - John D Wade
- Howard Florey Institute, University of Melbourne, Victoria, 3010, Australia
| | - Marilyn A Anderson
- Department of Biochemistry, La Trobe University, Melbourne, Victoria, 3086, Australia
| | - David J Craik
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| |
Collapse
|
19
|
Cunha NBD, Barbosa AEADD, de Almeida RG, Porto WF, Maximiano MR, Álvares LCS, Munhoz CBR, Eugênio CUO, Viana AAB, Franco OL, Dias SC. Cloning and characterization of novel cyclotides genes from South American plants. Biopolymers 2017; 106:784-795. [PMID: 27554590 DOI: 10.1002/bip.22938] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2016] [Revised: 08/10/2016] [Accepted: 08/21/2016] [Indexed: 01/06/2023]
Abstract
Cyclotides are multifunctional plant cyclic peptides containing 28-37 amino acid residues and a pattern of three disulfide bridges, forming a motif known as the cyclic cystine knot. Due to their high biotechnological potential, the sequencing and characterization of cyclotide genes are crucial not only for cloning and establishing heterologous expression strategies, but also to understand local plant evolution in the context of host-pathogen relationships. Here, two species from the Brazilian Cerrado, Palicourea rigida (Rubiaceae) and Pombalia lanata (A.St.-Hil.) Paula-Souza (Violaceae), were used for cloning and characterizing novel cyclotide genes. Using 3' and 5' RACE PCR and sequencing, two full cDNAs, named parigidin-br2 (P. rigida) and hyla-br1 (P. lanata), were isolated and shown to have similar genetic structures to other cyclotides. Both contained the conserved ER-signal domain, N-terminal prodomain, mature cyclotide domain and a C-terminal region. Genomic sequencing of parigidin-br2 revealed two different gene copies: one intronless allele and one presenting a rare 131-bp intron. In contrast, genomic sequencing of hyla-br1 revealed an intronless gene-a common characteristic of members of the Violaceae family. Parigidin-br2 5' and 3' UTRs showed the presence of 12 putative candidate sites for binding of regulatory proteins, suggesting that the flanking and intronic regions of the parigidin-br2 gene must play important roles in transcriptional rates and in the regulation of temporal and spatial gene expression. The high degree of genetic similarity and structural organization among the cyclotide genes isolated in the present study from the Brazilian Cerrado and other well-characterized plant cyclotides may contribute to a better understanding of cyclotide evolution.
Collapse
Affiliation(s)
- Nicolau Brito da Cunha
- Centro de Analises Proteômicas e Bioquímicas, Pós-graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, SGAN 916 Módulo B Avenida W5, Brasília, DF, 70790-160, Brazil
| | | | - Renato Goulart de Almeida
- Centro de Analises Proteômicas e Bioquímicas, Pós-graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, SGAN 916 Módulo B Avenida W5, Brasília, DF, 70790-160, Brazil
| | - William Farias Porto
- Centro de Analises Proteômicas e Bioquímicas, Pós-graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, SGAN 916 Módulo B Avenida W5, Brasília, DF, 70790-160, Brazil
| | - Mariana Rocha Maximiano
- Centro de Analises Proteômicas e Bioquímicas, Pós-graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, SGAN 916 Módulo B Avenida W5, Brasília, DF, 70790-160, Brazil
| | - Luana Cristina Silva Álvares
- Centro de Analises Proteômicas e Bioquímicas, Pós-graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, SGAN 916 Módulo B Avenida W5, Brasília, DF, 70790-160, Brazil
| | - Cassia Beatriz Rodrigues Munhoz
- Departamento de Botânica, Instituto de Ciências Biológicas. Bloco D. Universidade de Brasília. Campus Darcy Ribeiro 70904-970, Asa Norte. Brasília, DF, Brazil
| | - Chesterton Ulysses Orlando Eugênio
- Centro de Analises Proteômicas e Bioquímicas, Pós-graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, SGAN 916 Módulo B Avenida W5, Brasília, DF, 70790-160, Brazil
| | - Antônio Américo Barbosa Viana
- Centro de Analises Proteômicas e Bioquímicas, Pós-graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, SGAN 916 Módulo B Avenida W5, Brasília, DF, 70790-160, Brazil
| | - Octavio Luiz Franco
- Centro de Analises Proteômicas e Bioquímicas, Pós-graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, SGAN 916 Módulo B Avenida W5, Brasília, DF, 70790-160, Brazil.,S-Inova Biotech, Pós Graduação em Biotecnologia, Universidade Católica Dom Bosco, Campo Grande, MS, Brazil
| | - Simoni Campos Dias
- Centro de Analises Proteômicas e Bioquímicas, Pós-graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, SGAN 916 Módulo B Avenida W5, Brasília, DF, 70790-160, Brazil
| |
Collapse
|
20
|
Molesini B, Treggiari D, Dalbeni A, Minuz P, Pandolfini T. Plant cystine-knot peptides: pharmacological perspectives. Br J Clin Pharmacol 2017; 83:63-70. [PMID: 26987851 PMCID: PMC5338163 DOI: 10.1111/bcp.12932] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 03/07/2016] [Accepted: 03/09/2016] [Indexed: 12/29/2022] Open
Abstract
Cystine-knot miniproteins are a class of 30-50 amino acid long peptides widespread in eukaryotic organisms. Due to their very peculiar three-dimensional structure, they exhibit high resistance to heat and peptidase attack. The cystine-knot peptides are well represented in several plant species including medicinal herbs and crops. The pharmacological interest in plant cystine-knot peptides derives from their broad biological activities, mainly cytotoxic, antimicrobial and peptidase inhibitory and in the possibility to engineer them to incorporate pharmacophoric information for oral delivery or disease biomonitoring. The mechanisms of action of plant cystine-knot peptides are still largely unknown, although the capacity to interfere with plasma membranes seems a feature common to several cystine-knot peptides. In some cases, such as potato carboxypetidase inhibitor (PCI) and tomato cystine-knot miniproteins (TCMPs), the cystine-knot peptides target human growth factor receptors either by acting as growth factor antagonist or by altering their signal transduction pathway. The possibility to identify specific molecular targets of plant cystine-knot peptides in human cells opens novel possibilities for the pharmacological use of these peptides besides their use as scaffold to develop stable disease molecular markers and therapeutic agents.
Collapse
Affiliation(s)
| | - Davide Treggiari
- Department of Medicine, Section of Internal MedicineUniversity of VeronaVeronaItaly
| | - Andrea Dalbeni
- Department of Medicine, Section of Internal MedicineUniversity of VeronaVeronaItaly
| | - Pietro Minuz
- Department of Medicine, Section of Internal MedicineUniversity of VeronaVeronaItaly
| | | |
Collapse
|
21
|
Park S, Yoo KO, Marcussen T, Backlund A, Jacobsson E, Rosengren KJ, Doo I, Göransson U. Cyclotide Evolution: Insights from the Analyses of Their Precursor Sequences, Structures and Distribution in Violets ( Viola). FRONTIERS IN PLANT SCIENCE 2017; 8:2058. [PMID: 29326730 PMCID: PMC5741643 DOI: 10.3389/fpls.2017.02058] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 11/17/2017] [Indexed: 05/20/2023]
Abstract
Cyclotides are a family of plant proteins that are characterized by a cyclic backbone and a knotted disulfide topology. Their cyclic cystine knot (CCK) motif makes them exceptionally resistant to thermal, chemical, and enzymatic degradation. By disrupting cell membranes, the cyclotides function as host defense peptides by exhibiting insecticidal, anthelmintic, antifouling, and molluscicidal activities. In this work, we provide the first insight into the evolution of this family of plant proteins by studying the Violaceae, in particular species of the genus Viola. We discovered 157 novel precursor sequences by the transcriptomic analysis of six Viola species: V. albida var. takahashii, V. mandshurica, V. orientalis, V. verecunda, V. acuminata, and V. canadensis. By combining these precursor sequences with the phylogenetic classification of Viola, we infer the distribution of cyclotides across 63% of the species in the genus (i.e., ~380 species). Using full precursor sequences from transcriptomes, we show an evolutionary link to the structural diversity of the cyclotides, and further classify the cyclotides by sequence signatures from the non-cyclotide domain. Also, transcriptomes were compared to cyclotide expression on a peptide level determined using liquid chromatography-mass spectrometry. Furthermore, the novel cyclotides discovered were associated with the emergence of new biological functions.
Collapse
Affiliation(s)
- Sungkyu Park
- Division of Pharmacognosy, Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
| | - Ki-Oug Yoo
- Department of Biological Sciences, Kangwon National University, Chuncheon, South Korea
| | - Thomas Marcussen
- Department of Biosciences, Centre for Ecological and Evolutionary Synthesis, University of Oslo, Oslo, Norway
| | - Anders Backlund
- Division of Pharmacognosy, Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
| | - Erik Jacobsson
- Division of Pharmacognosy, Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
| | - K. Johan Rosengren
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Inseok Doo
- Biotech Research Team, Biotech Research Center of Dong-A Pharm Co Ltd., Seoul, South Korea
| | - Ulf Göransson
- Division of Pharmacognosy, Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
- *Correspondence: Ulf Göransson
| |
Collapse
|
22
|
Koehbach J, Clark RJ. Unveiling the diversity of cyclotides by combining peptidome and transcriptome analysis. Biopolymers 2016; 106:774-783. [DOI: 10.1002/bip.22858] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 04/05/2016] [Accepted: 04/11/2016] [Indexed: 01/11/2023]
Affiliation(s)
- Johannes Koehbach
- School of Biomedical Sciences; The University of Queensland; 4072 St. Lucia QLD Australia
| | - Richard J. Clark
- School of Biomedical Sciences; The University of Queensland; 4072 St. Lucia QLD Australia
| |
Collapse
|
23
|
Niyomploy P, Chan LY, Poth AG, Colgrave ML, Sangvanich P, Craik DJ. Discovery, isolation, and structural characterization of cyclotides from
Viola sumatrana
Miq. Pept Sci (Hoboken) 2016; 106:796-805. [DOI: 10.1002/bip.22914] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 06/21/2016] [Accepted: 06/29/2016] [Indexed: 01/18/2023]
Affiliation(s)
- Ploypat Niyomploy
- Institute for Molecular Bioscience, The University of QueenslandBrisbane QLD4072 Australia
- Department of Chemistry, Faculty of ScienceChulalongkorn UniversityBangkok10330 Thailand
| | - Lai Yue Chan
- Institute for Molecular Bioscience, The University of QueenslandBrisbane QLD4072 Australia
| | - Aaron G. Poth
- Institute for Molecular Bioscience, The University of QueenslandBrisbane QLD4072 Australia
| | | | - Polkit Sangvanich
- Department of Chemistry, Faculty of ScienceChulalongkorn UniversityBangkok10330 Thailand
| | - David J. Craik
- Institute for Molecular Bioscience, The University of QueenslandBrisbane QLD4072 Australia
| |
Collapse
|
24
|
Mahatmanto T. Review seed biopharmaceutical cyclic peptides: From discovery to applications. Biopolymers 2016; 104:804-14. [PMID: 26385189 DOI: 10.1002/bip.22741] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 08/17/2015] [Accepted: 09/16/2015] [Indexed: 02/02/2023]
Abstract
Mini-proteins (or peptides) with disulfide bond/s and a cyclic backbone offer exciting opportunities for applications in medicine, as these ribosomally synthesized and posttranslationally modified peptides are exceptionally stable and amenable to grafting epitopes with desirable activities. Here I discuss important aspects of the discovery and applications of disulfide-bonded cyclic peptides from seeds, i.e., the trypsin inhibitor cyclotides and the preproalbumin with sunflower trypsin inhibitor-derived peptides, focusing on bioanalytical methods for and insights generated from their discovery as well as their potential use as engineering scaffolds for peptide-based drug design. The recent discovery of their precursors and processing enzymes could potentially enable in planta production of designer disulfide-bonded cyclic peptides, preferably in edible seeds, and address the demand for new biopharmaceutical peptides in a cost-effective manner.
Collapse
Affiliation(s)
- Tunjung Mahatmanto
- Department of Agricultural Product Technology, Faculty of Agricultural Technology, Brawijaya University, Malang, East Java, 65145, Indonesia
| |
Collapse
|
25
|
Rosengren KJ, Daly NL, Harvey PJ, Craik DJ. The self-association of the cyclotide kalata B2 in solution is guided by hydrophobic interactions. Biopolymers 2016; 100:453-60. [PMID: 23893463 DOI: 10.1002/bip.22269] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2013] [Revised: 04/17/2013] [Accepted: 04/19/2013] [Indexed: 01/28/2023]
Abstract
The cyclotides are a family of small head-to-tail cyclic plant defense proteins. In addition to their cyclic backbone, cyclotides comprise three disulfide bonds in a knotted arrangement, resulting in a highly cross-braced structure that provides exceptional chemical and proteolytic stability. A number of bioactivities have been associated with cyclotides, including insecticidal, antimicrobial, anti-viral and cytotoxic, and these activities are related to an ability to target and disrupt biological membranes. Kalata B2 and to a lesser extent kalata B1, isolated from Oldenlandia affinis, self-associate to tetramers and octamers in aqueous buffers, and this oligomerization has been suggested to be relevant for their ability to form pores in membranes. Here we demonstrate by solution NMR spectroscopy analysis that the oligomerization of kalata B2 is concentration dependent and that it involves the packing of hydrophobic residues normally exposed on the surface of kalata B2 into a multimeric hydrophobic core. Interestingly, the hydrophobic surface that is "quenched" has previously been shown to be responsible for the ability of kalata B2 to insert into membranes. Thus, it seems unlikely that the oligomers observed in aqueous solution are related to any multimeric state present in a membrane environment, and responsible for the formation of pores. The ability to self-associate might alternatively provide a mechanism for preventing self-toxicity when stored at high concentrations in intracellular compartments.
Collapse
Affiliation(s)
- K Johan Rosengren
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, 4072, Australia; Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| | | | | | | |
Collapse
|
26
|
Nguyen KNT, Nguyen GKT, Nguyen PQT, Ang KH, Dedon PC, Tam JP. Immunostimulating and Gram-negative-specific antibacterial cyclotides from the butterfly pea (Clitoria ternatea). FEBS J 2016; 283:2067-90. [DOI: 10.1111/febs.13720] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 02/05/2016] [Accepted: 03/22/2016] [Indexed: 12/18/2022]
Affiliation(s)
- Kim Ngan T. Nguyen
- School of Biological Sciences; Nanyang Technological University; Singapore City Singapore
| | - Giang Kien Truc Nguyen
- School of Biological Sciences; Nanyang Technological University; Singapore City Singapore
| | | | - Koon Hwee Ang
- School of Biological Sciences; Nanyang Technological University; Singapore City Singapore
| | - Peter C. Dedon
- Department of Biological Engineering; Massachusetts Institute of Technology; Cambridge MA USA
| | - James P. Tam
- School of Biological Sciences; Nanyang Technological University; Singapore City Singapore
| |
Collapse
|
27
|
Gilding EK, Jackson MA, Poth AG, Henriques ST, Prentis PJ, Mahatmanto T, Craik DJ. Gene coevolution and regulation lock cyclic plant defence peptides to their targets. THE NEW PHYTOLOGIST 2016; 210:717-30. [PMID: 26668107 DOI: 10.1111/nph.13789] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 10/28/2015] [Indexed: 05/20/2023]
Abstract
Plants have evolved many strategies to protect themselves from attack, including peptide toxins that are ribosomally synthesized and thus adaptable directly by genetic polymorphisms. Certain toxins in Clitoria ternatea (butterfly pea) are cyclic cystine-knot peptides of c. 30 residues, called cyclotides, which have co-opted the plant's albumin-1 gene family for their production. How butterfly pea albumin-1 genes were commandeered and how these cyclotides are utilized in defence remain unclear. The role of cyclotides in host plant ecology and biotechnological applications requires exploration. We characterized the sequence diversity and expression dynamics of precursor and processing proteins implicated in butterfly pea cyclotide biosynthesis by expression profiling through RNA-sequencing (RNA-seq). Peptide-enriched extracts from various organs were tested for activity against insect-like membranes and the model nematode Caenorhabditis elegans. We found that the evolution and deployment of cyclotides involved their diversification to exhibit different chemical properties and expression between organs facing different defensive challenges. Cyclotide-enriched fractions from soil-contacting organs were effective at killing nematodes, whereas similar enriched fractions from aerial organs contained cyclotides that exhibited stronger interactions with insect-like membrane lipids. Cyclotides are employed as versatile and combinatorial mediators of defence in C. ternatea and have specialized to affect different classes of attacking organisms.
Collapse
Affiliation(s)
- Edward K Gilding
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia
| | - Mark A Jackson
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia
| | - Aaron G Poth
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia
| | - Sónia Troeira Henriques
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia
| | - Peter J Prentis
- Earth, Environment, and Biological Sciences, Queensland University of Technology, Brisbane, Qld, 4000, Australia
| | - Tunjung Mahatmanto
- 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
| |
Collapse
|
28
|
Jones PM, George AM. Computational analysis of the MCoTI-II plant defence knottin reveals a novel intermediate conformation that facilitates trypsin binding. Sci Rep 2016; 6:23174. [PMID: 26975976 PMCID: PMC4791599 DOI: 10.1038/srep23174] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 02/25/2016] [Indexed: 11/09/2022] Open
Abstract
MCoTI-I and II are plant defence proteins, potent trypsin inhibitors from the bitter gourd Momordica cochinchinensis. They are members of the Knottin Family, which display exceptional stability due to unique topology comprising three interlocked disulfide bridges. Knottins show promise as scaffolds for new drug development. A crystal structure of trypsin-bound MCoTI-II suggested that loop 1, which engages the trypsin active site, would show decreased dynamics in the bound state, an inference at odds with an NMR analysis of MCoTI-I, which revealed increased dynamics of loop 1 in the presence of trypsin. To investigate this question, we performed unrestrained MD simulations of trypsin-bound and free MCoTI-II. This analysis found that loop 1 of MCoTI-II is not more dynamic in the trypsin-bound state than in the free state. However, it revealed an intermediate conformation, transitional between the free and bound MCoTI-II states. The data suggest that MCoTI-II binding involves a process in which initial interaction with trypsin induces transitions between the free and intermediate conformations, and fluctuations between these states account for the increase in dynamics of loop 1 observed for trypsin-bound MCoTI-I. The MD analysis thus revealed new aspects of the inhibitors’ dynamics that may be of utility in drug design.
Collapse
Affiliation(s)
- Peter M Jones
- School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW 2007 Australia
| | - Anthony M George
- School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW 2007 Australia
| |
Collapse
|
29
|
Akcan M, Clark RJ, Daly NL, Conibear AC, de Faoite A, Heghinian MD, Sahil T, Adams DJ, Marí F, Craik DJ. Transforming conotoxins into cyclotides: Backbone cyclization of P-superfamily conotoxins. Biopolymers 2015; 104:682-92. [DOI: 10.1002/bip.22699] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 06/17/2015] [Accepted: 07/04/2015] [Indexed: 01/08/2023]
Affiliation(s)
- Muharrem Akcan
- Institute for Molecular Bioscience; The University of Queensland; Brisbane QLD 4072 Australia
| | - Richard J. Clark
- 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
| | - Anne C. Conibear
- Institute for Molecular Bioscience; The University of Queensland; Brisbane QLD 4072 Australia
| | - Andrew de Faoite
- Health Innovations Research Institute; RMIT University; Bundoora VIC 3083 Australia
| | - Mari D. Heghinian
- Department of Chemistry and Biochemistry; Florida Atlantic University; FL 33431 USA
| | - Talwar Sahil
- Queensland Brain Institute; The University of Queensland; Brisbane QLD 4072 Australia
| | - David J. Adams
- Health Innovations Research Institute; RMIT University; Bundoora VIC 3083 Australia
| | - Frank Marí
- Department of Chemistry and Biochemistry; Florida Atlantic University; FL 33431 USA
| | - David J. Craik
- Institute for Molecular Bioscience; The University of Queensland; Brisbane QLD 4072 Australia
| |
Collapse
|
30
|
Phoenix DA, Harris F, Mura M, Dennison SR. The increasing role of phosphatidylethanolamine as a lipid receptor in the action of host defence peptides. Prog Lipid Res 2015; 59:26-37. [PMID: 25936689 DOI: 10.1016/j.plipres.2015.02.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 02/26/2015] [Accepted: 02/27/2015] [Indexed: 01/04/2023]
Abstract
Host defence peptides (HDPs) are antimicrobial agents produced by organisms across the prokaryotic and eukaryotic kingdoms. Many prokaryotes produce HDPs, which utilise lipid and protein receptors in the membranes of bacterial competitors to facilitate their antibacterial action and thereby survive in their niche environment. As a major example, it is well established that cinnamycin and duramycins from Streptomyces have a high affinity for phosphatidylethanolamine (PE) and exhibit activity against other Gram-positive organisms, such as Bacillus. In contrast, although eukaryotic HDPs utilise membrane interactive mechanisms to facilitate their antimicrobial activity, the prevailing view has long been that these mechanisms do not involve membrane receptors. However, this view has been recently challenged by reports that a number of eukaryotic HDPs such as plant cyclotides also use PE as a receptor to promote their antimicrobial activities. Here, we review current understanding of the mechanisms that underpin the use of PE as a receptor in the antimicrobial and other biological actions of HDPs and describe medical and biotechnical uses of these peptides, which range from tumour imaging and detection to inclusion in topical microbicidal gels to prevent the sexual transmission of HIV.
Collapse
Affiliation(s)
- David A Phoenix
- School of Applied Science, London South Bank University, 103 Borough Road, London SE1 0AA, UK.
| | - Frederick Harris
- School of Applied Science, London South Bank University, 103 Borough Road, London SE1 0AA, UK; School of Forensic and Investigative Science, University of Central Lancashire, Preston PR1 2HE, UK
| | - Manuela Mura
- School of Mathematics and Physics, College of Science, University of Lincoln, Brayford Pool, Lincoln, Lincolnshire LN6 7TS, UK
| | - Sarah R Dennison
- School of Applied Science, London South Bank University, 103 Borough Road, London SE1 0AA, UK; School of Pharmacy and Biomedical Sciences, University of Central Lancashire, Preston PR1 2HE, UK
| |
Collapse
|
31
|
Zhang J, Hua Z, Huang Z, Chen Q, Long Q, Craik DJ, Baker AJM, Shu W, Liao B. Two Blast-independent tools, CyPerl and CyExcel, for harvesting hundreds of novel cyclotides and analogues from plant genomes and protein databases. PLANTA 2015; 241:929-940. [PMID: 25528148 DOI: 10.1007/s00425-014-2229-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 12/10/2014] [Indexed: 06/04/2023]
Abstract
Two high-throughput tools harvest hundreds of novel cyclotides and analogues in plants. Cyclotides are gene-encoded backbone-cyclized polypeptides displaying a diverse range of bioactivities associated with plant defense. However, genome-scale or database-scale evaluations of cyclotides have been rare so far. Here, a novel time-efficient Perl program, CyPerl, was developed for searching cyclotides from predicted ORFs of 34 available plant genomes and existing plant protein sequences from Genbank databases. CyPerl-isolated sequences were further analyzed by removing repeats, evaluating their cysteine-distributed regions (CDRs) and comparing with CyBase-collected cyclotides in a user-friendly Excel (Microsoft Office) template, CyExcel. After genome-screening, 186 ORFs containing 145 unique cyclotide analogues were identified by CyPerl and CyExcel from 30 plant genomes tested from 10 plant families. Phaseolus vulgaris and Zea mays were the richest two species containing cyclotide analogues in the plants tested. After screening protein databases, 266 unique cyclotides and analogues were identified from seven plant families. By merging with 288 unique CyBase-listed cyclotides, 510 unique cyclotides and analogues were obtained from 13 plant families. In total, seven novel plant families containing cyclotide analogues and 202 novel cyclotide analogues were identified in this study. This study has established two Blast-independent tools for screening cyclotides from plant genomes and protein databases, and has also significantly widened the plant distribution and sequence diversity of cyclotides and their analogues.
Collapse
Affiliation(s)
- Jun Zhang
- School of Biosciences and Biopharmaceutics, Guangdong Province Key Laboratory for Biotechnology Drug Candidates, Guangdong Pharmaceutical University, Guangzhou, 510006, China,
| | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Nawae W, Hannongbua S, Ruengjitchatchawalya M. Dynamic scenario of membrane binding process of kalata b1. PLoS One 2014; 9:e114473. [PMID: 25473840 PMCID: PMC4256454 DOI: 10.1371/journal.pone.0114473] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 11/11/2014] [Indexed: 11/18/2022] Open
Abstract
Kalata B1 (kB1), a cyclotide that has been used in medical applications, displays cytotoxicity related to membrane binding and oligomerization. Our molecular dynamics simulation results demonstrate that Trp19 in loop 5 of both monomeric and tetrameric kB1 is a key residue for initial anchoring in the membrane binding process. This residue also facilitates the formation of kB1 tetramers. Additionally, we elucidate that kB1 preferentially binds to the membrane interfacial zone and is unable to penetrate into the membrane. In particular, significant roles of amino acid residues in loop 5 and loop 6 on the localization of kB1 to this membrane-water interface zone are found. This study reveals the roles of amino acid residues in the bioactivity of kB1, which is information that can be useful for designing new therapeutic cyclotides with less toxicity.
Collapse
Affiliation(s)
- Wanapinun Nawae
- Biological Engineering Program, Faculty of Engineering, King Mongkut's University of Technology Thonburi, Thung Khru, Bangkok, Thailand
| | - Supa Hannongbua
- Department of Chemistry, Faculty of Science, Kasetsart University, Chatuchak, Bangkok, Thailand
| | - Marasri Ruengjitchatchawalya
- Bioinformatics and Systems Biology program, King Mongkut's University of Technology Thonburi (Bang Khun Thian), Bang Khun Thian, Bangkok, Thailand; Biotechnology Program, School of Bioresources and Technology, King Mongkut's University of Technology Thonburi (Bang Khun Thian), Bang Khun Thian, Bangkok, Thailand
| |
Collapse
|
33
|
Mahatmanto T, Mylne JS, Poth AG, Swedberg JE, Kaas Q, Schaefer H, Craik DJ. The evolution of Momordica cyclic peptides. Mol Biol Evol 2014; 32:392-405. [PMID: 25376175 DOI: 10.1093/molbev/msu307] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Cyclic proteins have evolved for millions of years across all kingdoms of life to confer structural stability over their acyclic counterparts while maintaining intrinsic functional properties. Here, we show that cyclic miniproteins (or peptides) from Momordica (Cucurbitaceae) seeds evolved in species that diverged from an African ancestor around 19 Ma. The ability to achieve head-to-tail cyclization of Momordica cyclic peptides appears to have been acquired through a series of mutations in their acyclic precursor coding sequences following recent and independent gene expansion event(s). Evolutionary analysis of Momordica cyclic peptides reveals sites that are under selection, highlighting residues that are presumably constrained for maintaining their function as potent trypsin inhibitors. Molecular dynamics of Momordica cyclic peptides in complex with trypsin reveals site-specific residues involved in target binding. In a broader context, this study provides a basis for selecting Momordica species to further investigate the biosynthesis of the cyclic peptides and for constructing libraries that may be screened against evolutionarily related serine proteases implicated in human diseases.
Collapse
Affiliation(s)
- Tunjung Mahatmanto
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, Australia
| | - Joshua S Mylne
- The University of Western Australia, School of Chemistry and Biochemistry & The ARC Centre of Excellence in Plant Energy Biology, Crawley, Perth, WA, Australia
| | - Aaron G Poth
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, Australia
| | - Joakim E Swedberg
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, Australia
| | - Quentin Kaas
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, Australia
| | - Hanno Schaefer
- Plant Biodiversity Research, Technische Universität München, Freising, Germany
| | - David J Craik
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, Australia
| |
Collapse
|
34
|
Mahatmanto T, Poth AG, Mylne JS, Craik DJ. A comparative study of extraction methods reveals preferred solvents for cystine knot peptide isolation from Momordica cochinchinensis seeds. Fitoterapia 2014; 95:22-33. [PMID: 24613804 DOI: 10.1016/j.fitote.2014.02.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 02/21/2014] [Accepted: 02/25/2014] [Indexed: 11/16/2022]
Abstract
MCoTI-I and MCoTI-II (short for Momordica cochinchinensis Trypsin Inhibitor-I and -II, respectively) are attractive candidates for developing novel intracellular-targeting drugs because both are exceptionally stable and can internalize into cells. These seed-derived cystine knot peptides are examples of how natural product discovery efforts can lead to biomedical applications. However, discovery efforts are sometimes hampered by the limited availability of seed materials, highlighting the need for efficient extraction methods. In this study, we assessed five extraction methods using M. cochinchinensis seeds, a source of well-characterized cystine knot peptides. The most efficient extraction of nine known cystine knot peptides was achieved by a method based on acetonitrile/water/formic acid (25:24:1), followed by methods based on sodium acetate (20 mM, pH 5.0), ammonium bicarbonate (5 mM, pH 8.0), and boiling water. On average, the yields obtained by these four methods were more than 250-fold higher than that obtained using dichloromethane/methanol (1:1) extraction, a previously applied standard method. Extraction using acetonitrile/water/formic acid (25:24:1) yielded the highest number of reconstructed masses within the majority of plant-derived cystine knot peptide mass range but only accounted for around 50% of the total number of masses, indicating that any single method may result in under-sampling. Applying acetonitrile/water/formic acid (25:24:1), boiling water, and ammonium bicarbonate (5 mM, pH 8.0) extractions either successively or discretely significantly increased the sampling number. Overall, acetonitrile/water/formic acid (25:24:1) can facilitate efficient extraction of cystine-knot peptides from M. cochinchinensis seeds but for discovery purposes the use of a combination of extraction methods is recommended where practical.
Collapse
Affiliation(s)
- Tunjung Mahatmanto
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia.
| | - Aaron G Poth
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia.
| | - Joshua S Mylne
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia; School of Chemistry and Biochemistry & ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, Perth, Western Australia 6009, Australia.
| | - David J Craik
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia.
| |
Collapse
|
35
|
Jia X, Kwon S, Wang CIA, Huang YH, Chan LY, Tan CC, Rosengren KJ, Mulvenna JP, Schroeder CI, Craik DJ. Semienzymatic cyclization of disulfide-rich peptides using Sortase A. J Biol Chem 2014; 289:6627-6638. [PMID: 24425873 DOI: 10.1074/jbc.m113.539262] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Disulfide-rich cyclic peptides have generated great interest in the development of peptide-based therapeutics due to their exceptional stability toward chemical, enzymatic, or thermal attack. In particular, they have been used as scaffolds onto which bioactive epitopes can be grafted to take advantage of the favorable biophysical properties of disulfide-rich cyclic peptides. To date, the most commonly used method for the head-to-tail cyclization of peptides has been native chemical ligation. In recent years, however, enzyme-mediated cyclization has become a promising new technology due to its efficiency, safety, and cost-effectiveness. Sortase A (SrtA) is a bacterial enzyme with transpeptidase activity. It recognizes a C-terminal penta-amino acid motif, LPXTG, and cleaves the amide bond between Thr and Gly to form a thioacyl-linked intermediate. This intermediate undergoes nucleophilic attack by an N-terminal poly-Gly sequence to form an amide bond between the Thr and N-terminal Gly. Here, we demonstrate that sortase A can successfully be used to cyclize a variety of small disulfide-rich peptides, including the cyclotide kalata B1, α-conotoxin Vc1.1, and sunflower trypsin inhibitor 1. These peptides range in size from 14 to 29 amino acids and contain three, two, or one disulfide bond, respectively, within their head-to-tail cyclic backbones. Our findings provide proof of concept for the potential broad applicability of enzymatic cyclization of disulfide-rich peptides with therapeutic potential.
Collapse
Affiliation(s)
- Xinying Jia
- From QIMR Berghofer Medical Research, Brisbane 4000, Queensland, Australia; Institute for Molecular Bioscience, University of Queensland, Brisbane 4072, Queensland, Australia
| | - Soohyun Kwon
- Institute for Molecular Bioscience, University of Queensland, Brisbane 4072, Queensland, Australia
| | - Ching-I Anderson Wang
- Institute for Molecular Bioscience, University of Queensland, Brisbane 4072, Queensland, Australia
| | - Yen-Hua Huang
- Institute for Molecular Bioscience, University of Queensland, Brisbane 4072, Queensland, Australia
| | - Lai Y Chan
- Institute for Molecular Bioscience, University of Queensland, Brisbane 4072, Queensland, Australia
| | - Chia Chia Tan
- Institute for Molecular Bioscience, University of Queensland, Brisbane 4072, Queensland, Australia
| | - K Johan Rosengren
- School of Biomedical Sciences, University of Queensland, Brisbane 4072, Queensland, Australia
| | - Jason P Mulvenna
- From QIMR Berghofer Medical Research, Brisbane 4000, Queensland, Australia
| | - Christina I Schroeder
- Institute for Molecular Bioscience, University of Queensland, Brisbane 4072, Queensland, Australia.
| | - David J Craik
- Institute for Molecular Bioscience, University of Queensland, Brisbane 4072, Queensland, Australia.
| |
Collapse
|
36
|
Oxytocic plant cyclotides as templates for peptide G protein-coupled receptor ligand design. Proc Natl Acad Sci U S A 2013; 110:21183-8. [PMID: 24248349 DOI: 10.1073/pnas.1311183110] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Cyclotides are plant peptides comprising a circular backbone and three conserved disulfide bonds that confer them with exceptional stability. They were originally discovered in Oldenlandia affinis based on their use in traditional African medicine to accelerate labor. Recently, cyclotides have been identified in numerous plant species of the coffee, violet, cucurbit, pea, potato, and grass families. Their unique structural topology, high stability, and tolerance to sequence variation make them promising templates for the development of peptide-based pharmaceuticals. However, the mechanisms underlying their biological activities remain largely unknown; specifically, a receptor for a native cyclotide has not been reported hitherto. Using bioactivity-guided fractionation of an herbal peptide extract known to indigenous healers as "kalata-kalata," the cyclotide kalata B7 was found to induce strong contractility on human uterine smooth muscle cells. Radioligand displacement and second messenger-based reporter assays confirmed the oxytocin and vasopressin V1a receptors, members of the G protein-coupled receptor family, as molecular targets for this cyclotide. Furthermore, we show that cyclotides can serve as templates for the design of selective G protein-coupled receptor ligands by generating an oxytocin-like peptide with nanomolar affinity. This nonapeptide elicited dose-dependent contractions on human myometrium. These observations provide a proof of concept for the development of cyclotide-based peptide ligands.
Collapse
|
37
|
Daly NL, Thorstholm L, Greenwood KP, King GJ, Rosengren KJ, Heras B, Martin JL, Craik DJ. Structural insights into the role of the cyclic backbone in a squash trypsin inhibitor. J Biol Chem 2013; 288:36141-8. [PMID: 24169696 DOI: 10.1074/jbc.m113.528240] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
MCoTI-II is a head-to-tail cyclic peptide with potent trypsin inhibitory activity and, on the basis of its exceptional proteolytic stability, is a valuable template for the design of novel drug leads. Insights into inhibitor dynamics and interactions with biological targets are critical for drug design studies, particularly for protease targets. Here, we show that the cyclization and active site loops of MCoTI-II are flexible in solution, but when bound to trypsin, the active site loop converges to a single well defined conformation. This finding of reduced flexibility on binding is in contrast to a recent study on the homologous peptide MCoTI-I, which suggested that regions of the peptide are more flexible upon binding to trypsin. We provide a possible explanation for this discrepancy based on degradation of the complex over time. Our study also unexpectedly shows that the cyclization loop, not present in acyclic homologues, facilitates potent trypsin inhibitory activity by engaging in direct binding interactions with trypsin.
Collapse
|
38
|
Gerlach SL, Göransson U, Kaas Q, Craik DJ, Mondal D, Gruber CW. A systematic approach to document cyclotide distribution in plant species from genomic, transcriptomic, and peptidomic analysis. Biopolymers 2013; 100:433-7. [DOI: 10.1002/bip.22258] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Revised: 03/26/2013] [Accepted: 04/08/2013] [Indexed: 01/15/2023]
Affiliation(s)
- Samantha L. Gerlach
- Department of Pharmacology; School of Medicine; Tulane University; 1430 Tulane Ave New Orleans LA 70112
| | - Ulf Göransson
- Division of Pharmacognosy, Department of Medicinal Chemistry; Uppsala University; Biomedical Centre 574 S-75123 Uppsala Sweden
| | - Quentin Kaas
- Division of Chemistry and Structural Biology; Institute for Molecular Bioscience; University of Queensland; Brisbane Queensland 4072 Australia
| | - David J. Craik
- Division of Chemistry and Structural Biology; Institute for Molecular Bioscience; University of Queensland; Brisbane Queensland 4072 Australia
| | - Debasis Mondal
- Department of Pharmacology; School of Medicine; Tulane University; 1430 Tulane Ave New Orleans LA 70112
| | - Christian W. Gruber
- Center for Physiology and Pharmacology; Medical University of Vienna; Schwarzspanierstr. 17 1090 Vienna Austria
| |
Collapse
|
39
|
Koehbach J, Attah AF, Berger A, Hellinger R, Kutchan TM, Carpenter EJ, Rolf M, Sonibare MA, Moody JO, Ka-Shu Wong G, Dessein S, Greger H, Gruber CW. Cyclotide discovery in Gentianales revisited--identification and characterization of cyclic cystine-knot peptides and their phylogenetic distribution in Rubiaceae plants. Biopolymers 2013; 100:438-52. [PMID: 23897543 PMCID: PMC3816352 DOI: 10.1002/bip.22328] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 06/07/2013] [Indexed: 11/06/2022]
Abstract
Cyclotides are a unique class of ribosomally synthesized cysteine-rich miniproteins characterized by a head-to-tail cyclized backbone and three conserved disulfide-bonds in a knotted arrangement. Originally they were discovered in the coffee-family plant Oldenlandia affinis (Rubiaceae) and have since been identified in several species of the violet, cucurbit, pea, potato, and grass families. However, the identification of novel cyclotide-containing plant species still is a major challenge due to the lack of a rapid and accurate analytical workflow in particular for large sampling numbers. As a consequence, their phylogeny in the plant kingdom remains unclear. To gain further insight into the distribution and evolution of plant cyclotides, we analyzed ∼300 species of >40 different families, with special emphasis on plants from the order Gentianales. For this purpose, we have developed a refined screening methodology combining chemical analysis of plant extracts and bioinformatic analysis of transcript databases. Using mass spectrometry and transcriptome-mining, we identified nine novel cyclotide-containing species and their related cyclotide precursor genes in the tribe Palicoureeae. The characterization of novel peptide sequences underlines the high variability and plasticity of the cyclotide framework, and a comparison of novel precursor proteins from Carapichea ipecacuanha illustrated their typical cyclotide gene architectures. Phylogenetic analysis of their distribution within the Psychotria alliance revealed cyclotides to be restricted to Palicourea, Margaritopsis, Notopleura, Carapichea, Chassalia, and Geophila. In line with previous reports, our findings confirm cyclotides to be one of the largest peptide families within the plant kingdom and suggest that their total number may exceed tens of thousands.
Collapse
Affiliation(s)
- Johannes Koehbach
- Center for Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090 Vienna, Austria
| | - Alfred F. Attah
- Center for Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090 Vienna, Austria
- Department of Pharmacognosy, Faculty of Pharmacy, University of Ibadan, Ibadan, Nigeria
| | - Andreas Berger
- Department of Systematic and Evolutionary Botany, University of Vienna, Rennweg 14, 1030 Vienna, Austria
| | - Roland Hellinger
- Center for Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090 Vienna, Austria
| | | | - Eric J. Carpenter
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
- Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | - Megan Rolf
- Donald Danforth Plant Science Center, St. Louis, MO
| | - Mubo A. Sonibare
- Department of Pharmacognosy, Faculty of Pharmacy, University of Ibadan, Ibadan, Nigeria
| | - Jones O. Moody
- Department of Pharmacognosy, Faculty of Pharmacy, University of Ibadan, Ibadan, Nigeria
| | - Gane Ka-Shu Wong
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
- Department of Medicine, University of Alberta, Edmonton, AB, Canada
- BGI-Shenzhen, Bei Shan Industrial Zone, Yantian District, Shenzhen, China
| | - Steven Dessein
- National Botanic Garden of Belgium, Domein van Bouchout, 1860 Meise, Belgium
| | - Harald Greger
- Department of Systematic and Evolutionary Botany, University of Vienna, Rennweg 14, 1030 Vienna, Austria
| | - Christian W. Gruber
- Center for Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090 Vienna, Austria
- Department of Pharmacognosy, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| |
Collapse
|
40
|
Craik DJ, Malik U. Cyclotide biosynthesis. Curr Opin Chem Biol 2013; 17:546-54. [PMID: 23809361 DOI: 10.1016/j.cbpa.2013.05.033] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Accepted: 05/28/2013] [Indexed: 10/26/2022]
Abstract
Cyclotides are bioactive macrocyclic peptides from plants that are characterized by their exceptional stability and potential applications as protein engineering or drug design frameworks. Their stability arises from their unique cyclic cystine knot structure, which combines a head-to-tail cyclic peptide backbone with three conserved disulfide bonds having a knotted topology. Cyclotides are ribosomally synthesized by plants and expressed in a wide range of tissues, including leaves, flowers, stems and roots. Here we describe recent studies that have examined the biosynthesis of cyclotides and in particular the mechanism associated with post-translational backbone cyclization.
Collapse
Affiliation(s)
- David J Craik
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia.
| | | |
Collapse
|
41
|
Craik DJ. Joseph Rudinger memorial lecture: discovery and applications of cyclotides. J Pept Sci 2013; 19:393-407. [PMID: 23737440 DOI: 10.1002/psc.2523] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 05/02/2013] [Indexed: 12/31/2022]
Abstract
Cyclotides are plant-derived peptides of approximately 30 amino acids that have the characteristic structural features of a head-to-tail cyclized backbone and a cystine knot arrangement of their three conserved disulfide bonds. This article gives a personal account of the discovery of cyclotides, their characterization and their applications, based on work carried out in my laboratory over the last 20 years. It describes some of the background to their discovery and focuses on how their unique structural features lead to exceptional stability. This stability and their amenability to chemical synthesis have made it possible to use cyclotides as templates in protein engineering and drug design applications. These applications complement the interest in cyclotides deriving from their unique structures and natural function as host defense molecules.
Collapse
Affiliation(s)
- David J Craik
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia.
| |
Collapse
|
42
|
Kedarisetti P, Mizianty MJ, Kaas Q, Craik DJ, Kurgan L. Prediction and characterization of cyclic proteins from sequences in three domains of life. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2013; 1844:181-90. [PMID: 23669569 DOI: 10.1016/j.bbapap.2013.05.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2013] [Revised: 04/12/2013] [Accepted: 05/02/2013] [Indexed: 01/04/2023]
Abstract
Cyclic proteins (CPs) have circular chains with a continuous cycle of peptide bonds. Their unique structural traits result in greater stability and resistance to degradation when compared to their acyclic counterparts. They are also promising targets for pharmaceutical/therapeutic applications. To date, only a few hundred CPs are known, although recent studies suggest that their numbers might be substantially higher. Here we developed a first-of-its-kind, accurate and high-throughput method called CyPred that predicts whether a given protein chain is cyclic. CyPred considers currently well-represented CP families: cyclotides, cyclic defensins, bacteriocins, and trypsin inhibitors. Empirical tests demonstrate that CyPred outperforms commonly used alignment methods. We used CyPred to estimate the incidence of CPs and found ~3500 putative CPs among 5.7+ million chains from 642 fully sequenced proteomes from archaea, bacteria, and eukaryotes. The median number of putative CPs per species ranges from three for archaea proteomes to two for eukaryotes/bacteria, with 7% of archaea, 11% of bacterial, and 16% of eukaryotic proteomes having 10+ CPs. The differences in the estimated fractions of CPs per proteome are as large as three orders of magnitude. Among eukaryotes, animals have higher ratios of CPs compared to fungi, while plants have the largest spread of the ratios. We also show that proteomes enriched in cyclic proteins evolve more slowly than proteomes with fewer cyclic chains. Our results suggest that further research is needed to fully uncover the scope and potential of cyclic proteins. A list of putative CPs and the CyPred method are available at http://biomine.ece.ualberta.ca/CyPred/. This article is part of a Special Issue entitled: Computational Proteomics, Systems Biology & Clinical Implications. Guest Editor: Yudong Cai.
Collapse
Affiliation(s)
- Pradyumna Kedarisetti
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, AB, T6G 2V4, Canada
| | | | | | | | | |
Collapse
|
43
|
Sen Z, Zhan XK, Jing J, Yi Z, Wanqi Z. Chemosensitizing activities of cyclotides from Clitoria ternatea in paclitaxel-resistant lung cancer cells. Oncol Lett 2012; 5:641-644. [PMID: 23419988 PMCID: PMC3573133 DOI: 10.3892/ol.2012.1042] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2012] [Accepted: 11/13/2012] [Indexed: 12/03/2022] Open
Abstract
Cyclotides comprise a family of circular mini-peptides that have been isolated from various plants and have a wide range of bioactivities. Previous studies have demonstrated that cyclotides have antitumor effects and cause cell death by membrane permeabilization. The present study aimed to evaluate the cytotoxicity and chemosensitizing activities of cyclotides from Clitoria ternatea in paclitaxel-resistant lung cancer cells. In this study, a total of seven cyclotides were selected for colorimetric cell viability assay (MTT assay) to evaluate their anticancer and chemosensitizing activities in the lung cancer cell line A549 and its sub-line A549/paclitaxel. Results suggested that certain cyclotides had significant anticancer and chemosensitizing abilities; such cyclotides were capable of causing multi-fold decreases in the half maximal inhibitory concentration (IC50) value of cliotides in the presence of paclitaxel. More importantly, their bioactivities were found to be correlated with their net charge status. In conclusion, cyclotides from C. ternatea have potential in chemosensitization application.
Collapse
Affiliation(s)
- Zhang Sen
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050
| | | | | | | | | |
Collapse
|
44
|
Conlan BF, Colgrave ML, Gillon AD, Guarino R, Craik DJ, Anderson MA. Insights into processing and cyclization events associated with biosynthesis of the cyclic Peptide kalata B1. J Biol Chem 2012; 287:28037-46. [PMID: 22700963 PMCID: PMC3431668 DOI: 10.1074/jbc.m112.347823] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 05/31/2012] [Indexed: 11/06/2022] Open
Abstract
Plant cyclotides are the largest family of gene-encoded cyclic proteins. They act as host defense molecules to protect plants and are promising candidates as insecticidal and nematocidal agents in agriculture. For this promise to be realized a greater understanding of the post-translational processing of these proteins is needed. Cyclotides are cleaved from precursor proteins with subsequent ligation of the N and C termini to form a continuous peptide backbone. This cyclization step is inefficient in transgenic plants and our work aims to shed light on the specificity requirements at the excision sites for cyclic peptide production. Using the prototypic cyclotide kalata B1 (kB1) expressed from the Oak1 gene, MALDI-TOF mass spectrometry was used to examine the cyclization efficiency when mutants of the Oak1 gene were expressed in transgenic Nicotiana benthamiana. Cleavage at the N terminus of the cyclotide domain occurs rapidly with no strict specificity requirements for amino acids at the cleavage site. In contrast, the C-terminal region of the cyclotide domain in the P2, P1, P1', and P2' positions is highly conserved and only specific amino acids can occupy these positions. The cyclization reaction requires an Asn at position P1 followed by a small amino acid (Ala, Gly, Ser) at the P1' position. The P2' position must be filled by Leu or Ile; in their absence an unusual post-translational modification occurs. Substitution of the P2' Leu with Ala leads to hydroxylation of the neighboring proline. Through mutational analysis this novel proline hydroxylation motif was determined to be Gly-Ala-Pro-Ser.
Collapse
Affiliation(s)
- Brendon F. Conlan
- From the Department of Biochemistry, La Trobe University, Melbourne Victoria 3086
| | | | - Amanda D. Gillon
- From the Department of Biochemistry, La Trobe University, Melbourne Victoria 3086
| | - Rosemary Guarino
- From the Department of Biochemistry, La Trobe University, Melbourne Victoria 3086
| | - David J. Craik
- the Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Marilyn A. Anderson
- From the Department of Biochemistry, La Trobe University, Melbourne Victoria 3086
| |
Collapse
|
45
|
Poth AG, Mylne JS, Grassl J, Lyons RE, Millar AH, Colgrave ML, Craik DJ. Cyclotides associate with leaf vasculature and are the products of a novel precursor in petunia (Solanaceae). J Biol Chem 2012; 287:27033-46. [PMID: 22700981 DOI: 10.1074/jbc.m112.370841] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cyclotides are a large family of plant peptides that are structurally defined by their cyclic backbone and a trifecta of disulfide bonds, collectively known as the cyclic cystine knot (CCK) motif. Structurally similar cyclotides have been isolated from plants within the Rubiaceae, Violaceae, and Fabaceae families and share the CCK motif with trypsin-inhibitory knottins from a plant in the Cucurbitaceae family. Cyclotides have previously been reported to be encoded by dedicated genes or as a domain within a knottin-encoding PA1-albumin-like gene. Here we report the discovery of cyclotides and related non-cyclic peptides we called "acyclotides" from petunia of the agronomically important Solanaceae plant family. Transcripts for petunia cyclotides and acyclotides encode the shortest known cyclotide precursors. Despite having a different precursor structure, their sequences suggest that petunia cyclotides mature via the same biosynthetic route as other cyclotides. We assessed the spatial distribution of cyclotides within a petunia leaf section by MALDI imaging and observed that the major cyclotide component Phyb A was non-uniformly distributed. Dissected leaf midvein extracts contained significantly higher concentrations of this cyclotide compared with the lamina and outer margins of leaves. This is the third distinct type of cyclotide precursor, and Solanaceae is the fourth phylogenetically disparate plant family to produce these structurally conserved cyclopeptides, suggesting either convergent evolution upon the CCK structure or movement of cyclotide-encoding sequences within the plant kingdom.
Collapse
Affiliation(s)
- Aaron G Poth
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia
| | | | | | | | | | | | | |
Collapse
|
46
|
Göransson U, Burman R, Gunasekera S, Strömstedt AA, Rosengren KJ. Circular proteins from plants and fungi. J Biol Chem 2012; 287:27001-6. [PMID: 22700984 DOI: 10.1074/jbc.r111.300129] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Circular proteins, defined as head-to-tail cyclized polypeptides originating from ribosomal synthesis, represent a novel class of natural products attracting increasing interest. From a scientific point of view, these compounds raise questions of where and why they occur in nature and how they are formed. From a rational point of view, these proteins and their structural concept may be exploited for crop protection and novel pharmaceuticals. Here, we review the current knowledge of three protein families: cyclotides and circular sunflower trypsin inhibitors from the kingdom of plants and the Amanita toxins from fungi. A particular emphasis is placed on their biological origin, structure, and activity. In addition, the opportunity for discovery of novel circular proteins and recent insights into their mechanism of action are discussed.
Collapse
Affiliation(s)
- Ulf Göransson
- Division of Pharmacognosy, Department of Medicinal Chemistry, Biomedical Centre, Uppsala University, SE-75123 Uppsala, Sweden.
| | | | | | | | | |
Collapse
|
47
|
Affiliation(s)
- Spencer Bliven
- Bioinformatics Program, University of California, San Diego, La Jolla, California, United States of America
- * E-mail: (SB); (AP)
| | - Andreas Prlić
- San Diego Supercomputer Center, University of California San Diego, La Jolla, California, United States of America
- * E-mail: (SB); (AP)
| |
Collapse
|
48
|
Clark RJ, Akcan M, Kaas Q, Daly NL, Craik DJ. Cyclization of conotoxins to improve their biopharmaceutical properties. Toxicon 2012; 59:446-55. [DOI: 10.1016/j.toxicon.2010.12.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Accepted: 12/01/2010] [Indexed: 10/18/2022]
|
49
|
|
50
|
Pinto MFS, Almeida RG, Porto WF, Fensterseifer ICM, Lima LA, Dias SC, Franco OL. Cyclotides. J Evid Based Complementary Altern Med 2011. [DOI: 10.1177/2156587211428077] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
In recent years, a number of peptides containing a cyclic structural fold have been described. Among them, the cyclotides family was widely reported in different plant tissues, being composed of small cyclic peptides containing 6 conserved cysteine residues connected by disulfide bonds and forming a cysteine-binding cyclic structure known as a cyclic cysteine knot. This structural scaffold is responsible for an enhanced structural stability against chemical, thermal, and proteolytic degradation. Because of the observed stability and multifunctionality, including insecticidal, antimicrobial, and anti-HIV (human immunodeficiency virus) action, much effort has gone into trying to elucidate the structural-function relations of cyclotide compounds. This review focuses on the novelties involving gene structure, precursor formation and processing, and protein folding of the cyclotide family, shedding some light on molecular mechanisms of cyclotide production. Because cyclotides are clear targets for drug development and also biotechnology applications, their chemical synthesis, heterologous systems production, and protein grafting are also addressed.
Collapse
|