DOCSLIB.ORG

Discovery and Mode of Action of Cyclotides Anjaneya Swamy Ravipati Msc, M.Phil

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Discovery and mode of action of cyclotides Anjaneya Swamy Ravipati MSc, M.Phil A thesis submitted for the degree of Doctor of Philosophy at The University of Queensland in 2016 Institute for Molecular Bioscience Abstract Cyclotides are plant derived macrocyclic peptides featuring a cyclic cystine knot (CCK) formed by six cysteine residues on a head-to-tail cyclic backbone. Their unique structural features make them exceptionally stable against thermal, enzymatic or chemical degradation. Naturally isolated cyclotides have many pharmaceutically important activities, including uterotonic, anti-HIV, antimicrobial and anticancer properties. The combination of structural features and biological activities make cyclotides an attractive framework in drug design applications. To date over 300 cyclotides have been discovered in five plant families: Violaceae, Rubiaceae, Cucurbitaceae, Fabaceae and Solanaceae. However, their origin and distribution in the plant kingdom remains unclear. In this thesis a total of 206 plants belonging to 46 different plant families have been screened for expression of cyclotides. In this screening program, 50 novel cyclotides were discovered from 31 plant species belonging to the Rubiaceae and Violaceae families. Interestingly, all the Violaceae species possess cyclotides supporting the hypothesis that the Violaceae is a rich source of cyclotides. As a matter of fact, cyclotides have been found in every plant species belonging to the Violaceae family screened so far. It is noteworthy that a novel suite of Lys-rich cyclotides were discovered from Melicytus chathamicus and M. latifolius belonging to the Violaceae family which are endemic to remote islands of Australia and New Zealand. Unlike generic cyclotides, Lys-rich cyclotides possess higher positive charge, which correlates with their earlier retention times in RP-HPLC indicative of lower hydrophobic properties. i The broad spectrum of biological activities of cyclotides suggests the involvement of a common mechanism of action. Earlier studies have demonstrated that cyclotides exert biological activities through interaction with biological membranes. In order to understand the mode of action of novel cyclotides, membrane binding, and membrane permeabilization properties were evaluated on model membranes using a range of biophysical techniques including surface plasmon resonance (SPR), fluorescence spectroscopy and cryo- transmission electron microscopy (cryo-TEM). Regardless of their sequence diversity all of the cyclotides showed affinity towards phospholipids containing a phosphatidylethanolamine (PE) headgroup, which is in agreement with previous studies. In comparison to typical cyclotides, Lys-rich cyclotides display relatively lower haemolytic activities and correspondingly these peptides also showed lower affinities with model membranes. These results support the theory that membrane binding affinities influence the biological activities. The spectroscopic studies clearly show that cyclotides do target and disrupt membranes. However, the complete membrane disruption mechanism has not been evaluated yet. In this thesis, cyclotide-membrane interactions were investigated using cryo-TEM imaging. The results suggest that the membrane disruption mechanism is sequence dependent. Overall, the thesis has provided an increased understanding of the natural diversity of cyclotides and has added to our understanding of their mode of action. In particular, the discovery of a novel family of Lys-rich cyclotides suggests that there might be other new types of cyclotides yet to be discovered. Hence, discovery and characterization of cyclotides in this field of research has much to offer. ii Declaration by author This thesis is composed of my original work, and contains no material previously published or written by another person except where due reference has been made in the text. I have clearly stated the contribution by others to jointly-authored works that I have included in my thesis. I have clearly stated the contribution of others to my thesis as a whole, including statistical assistance, survey design, data analysis, significant technical procedures, professional editorial advice, and any other original research work used or reported in my thesis. The content of my thesis is the result of work I have carried out since the commencement of my research higher degree candidature and does not include a substantial part of work that has been submitted to qualify for the award of any other degree or diploma in any university or other tertiary institution. I have clearly stated which parts of my thesis, if any, have been submitted to qualify for another award. I acknowledge that an electronic copy of my thesis must be lodged with the University Library and, subject to the policy and procedures of The University of Queensland, the thesis be made available for research and study in accordance with the Copyright Act 1968 unless a period of embargo has been approved by the Dean of the Graduate School. I acknowledge that copyright of all material contained in my thesis resides with the copyright holder(s) of that material. Where appropriate I have obtained copyright permission from the copyright holder to reproduce material in this thesis. iii Publications during candidature Peer-reviewed papers 1. Cemazar, M., Kwon, S., Mahatmanto, T., Ravipati, A. S, and J Craik, D. (2012). Discovery and applications of disulfide-rich cyclic peptides, Current Topics in Medicinal Chemistry 12, 1534-1545. 2. Fensterseifer, I. C., Silva, O. N., Malik, U., Ravipati, A. S., Novaes, N. R., Miranda, P. R., Rodrigues, E. A., Moreno, S. E., Craik, D. J. and Franco, O. L. (2014). Effects of cyclotides against cutaneous infections caused by Staphylococcus aureus. Peptides. 63, 38-42. 3. Ravipati, A. S., Henriques, S. T., Poth, A. G., Kaas, Q., Wang, C. K., Colgrave, M. L., and Craik, D. J. (2015). Lysine-rich cyclotides: A new subclass of circular knotted proteins from Violaceae. ACS Chemical Biology 10, 2491-2500. 4. Ravipati, A. S., Henriques, S. T., Poth, A. G., Kaas, Q., Wang, C. K., Colgrave, M. L., and Craik, D. J. (2015). Discovery and mechanistic studies of cyclotides. Proceedings of 24th APS compilation of materials. iv Conference abstracts 1. Poster presentation: “Discovery and mechanistic studies of cyclotides” at 24th American Peptide Symposium, Orlando, Florida, USA. (20 – 25 Jun 2015) 2. Poster presentation: “Discovery, mechanistic studies and applications of cyclotides”, at Nanotechnology Entrepreneurship Workshop for Early Career Researchers, Griffth University, Gold Coast. (10 -11 Jun 2015) 3. Poster presentation: “Discovery and characterization of lysine rich cyclotides from critically endangered species from Australian continent” at ASMR QLD Postgraduate Student Conference, Brisbane, QLD, Australia. (29 May 2013) 4. Poster presentation: “Novel cyclotides from Palicourea guianensis Aubl. (Showy cappel)” at International Conference on Circular Proteins 2012, Heron Island, Australia. (14 - 17 October 2012) 5. Oral and poster presentation: “Evaluation of Antioxidant and Anti-inflammatory Activities of Chinese medicinal plants Extracts” at 27th International Symposium on the Chemistry of Natural Products, Brisbane, QLD, Australia. (10-15 July 2011) 6. Oral presentation: “Isolation and identification of biomarkers and cyclic peptides from medicinal herbs” at Student Conference and Careers day, University of Western Sydney. (Feb 2011) v Publications included in this thesis 1. Ravipati, A. S., Henriques, S. T., Poth, A. G., Kaas, Q., Wang, C. K., Colgrave, M. L., and Craik, D. J. (2015). Lysine-rich cyclotides: A new subclass of circular knotted proteins from Violaceae. ACS Chemical Biology 10, 2491-2500. (incorporated as Chapter 3). Contributor Statement of contribution Ravipati, A. S. (Candidate) Designed experiments (80%) Plant species collection (90%) Peptide isolation and purification (100%) Peptide sequencing (90%) Statistical analysis of data (60%) Membrane binding studies (90%) Structure-activity relationship (80%) Wrote and revision of paper (70%) Preparation of figures (80%) Henriques, S. T. Designed experiments (20%) Membrane binding studies (10%) Revised the paper (10%) Revision of figures (10%) Poth, A. G. Peptide sequencing (5%) Kaas, Q. Statistical analysis of data (40%) Wang, C. K. Structure-activity relationship (20%) Colgrave, M. L. Peptide sequencing (5%) Revision of figures (5%) Craik, D. J. Plant species collection (10%) Revision of figures (5%) Revised the paper (20%) vi Contributions by others to the thesis Amino acid analysis of peptides was carried out by Linda Chan at Florey Neuroscience Institutes, The University of Melbourne. Murari Bhandari and Akello helped with purification of cyclotides described in Chapter 4. Bacterial assays described in Chapter 3 were conducted by Dr. Sonia Henriques. Cytotoxicity assays against cultured mammalian cells described in Chapters 3 and 5 were conducted by Stephonie Chaousis and Dr. Sonia Henriques. Statistics on cyclotides described in Chapter 3 were conducted by Dr. Quentin Kaas. Dr. Aaron Poth and Michelle Colgrave confirmed the peptide sequences Garry Morgan conducted TEM imaging described in Chapter 6. Dr. Conan Wang helped with the modelling of Lys-rich cyclotides (Chapter 3) Statement of parts of the thesis submitted to qualify for the award of another degree None vii Acknowledgements During my PhD, many people offered me valuable guidance and support directly or indirectly. I would like to wholeheartedly
Recommended publications
  • Germination at Extreme Temperatures: Implications for Alpine Shrub Encroachment

    Germination at Extreme Temperatures: Implications for Alpine Shrub Encroachment

    plants Communication Germination at Extreme Temperatures: Implications for Alpine Shrub Encroachment Susanna E. Venn 1,2,* , Rachael V. Gallagher 3 and Adrienne B. Nicotra 2 1 Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Burwood, VIC 3125, Australia 2 Research School of Biology, Australian National University, Acton, ACT 2600, Australia; [email protected] 3 Department of Biological Sciences, Macquarie University, North Ryde, NSW 2109, Australia; [email protected] * Correspondence: [email protected] Abstract: Worldwide, shrub cover is increasing across alpine and tundra landscapes in response to warming ambient temperatures and declines in snowpack. With a changing climate, shrub encroachment may rely on recruitment from seed occurring outside of the optimum temperature range. We used a temperature gradient plate in order to determine the germination niche of 14 alpine shrub species. We then related the range in laboratory germination temperatures of each species to long-term average temperature conditions at: (1) the location of the seed accession site and (2) across each species geographic distribution. Seven of the species failed to germinate sufficiently to be included in the analyses. For the other species, the germination niche was broad, spanning a range in temperatures of up to 17 ◦C, despite very low germination rates in some species. Temperatures associated with the highest germination percentages were all above the range of temperatures present at each specific seed accession site. Optimum germination temperatures were consistently within or Citation: Venn, S.E.; Gallagher, R.V.; higher than the range of maximum temperatures modelled across the species’ geographic distribution.
  • Engineering of the Ultra-Stable Cystine Knot Framework Of

    Engineering of the Ultra-Stable Cystine Knot Framework Of

    !"# $ % %&#' (!!) *+*, (!&) -.++/.00+ 1 22 211234/+-/ 77 To my mother and father List of papers This thesis is based on the following papers, which are referred to in the text by their Roman numerals. I Aboye, T. L., Johan, K. R., Gunasekera, S., Bruhn, J. B., El- Seedi, H., Göransson, U. (2011) Discovery, synthesis, and structural determination of a toxin-like disulfide-rich peptide from the cactus Trichocereus pachanoi. Manuscript. II Aboye, T. L., Clark, R. J., Craik, D. J., Göransson, U. (2008) Ultra-stable peptide scaffolds for protein engineering: Synthsis and folding of the circular cystine knotted cyclotide cycloviola- cin O2. ChemBioChem, 9(1): 103–113 III Park, S., Gunasekera, S., Aboye, T. L., Göransson, U. (2010) An efficient approach for the total synthesis of cyclotides by microwave assisted Fmoc-SPPS. International Journal of Pep- tide Research and Therapeutics, 16(3): 167-176 IV Aboye, T. L., Clark, R. J., Burman, R., Roig, M. B., Craik, D. J., Göransson, U. (2011)
  • Pharmacokinetic Characterization of Kalata B1 and Related Therapeutics Built on the Cyclotide Scaffold

    Pharmacokinetic Characterization of Kalata B1 and Related Therapeutics Built on the Cyclotide Scaffold

    Accepted Manuscript Pharmacokinetic characterization of kalata B1 and related therapeutics built on the cyclotide scaffold Aaron G. Poth, Yen-Hua Huang, Thao T. Le, Meng-Wei Kan, David J. Craik PII: S0378-5173(19)30354-0 DOI: https://doi.org/10.1016/j.ijpharm.2019.05.001 Reference: IJP 18331 To appear in: International Journal of Pharmaceutics Received Date: 31 January 2019 Revised Date: 24 April 2019 Accepted Date: 3 May 2019 Please cite this article as: A.G. Poth, Y-H. Huang, T.T. Le, M-W. Kan, D.J. Craik, Pharmacokinetic characterization of kalata B1 and related therapeutics built on the cyclotide scaffold, International Journal of Pharmaceutics (2019), doi: https://doi.org/10.1016/j.ijpharm.2019.05.001 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Pharmacokinetic characterization of kalata B1 and related therapeutics built on the cyclotide scaffold Aaron G. Potha, Yen-Hua Huanga, Thao T. Lea,b, Meng-Wei Kana, David J. Craika* aInstitute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia Email addresses: Aaron G. Poth: [email protected] Yen-Hua Huang: [email protected] Thao T.
  • Report on the Grimwade Plant Collection of Percival St John and Botanical Exploration of Mt Buffalo National Park (Victoria, Australia)

    Report on the Grimwade Plant Collection of Percival St John and Botanical Exploration of Mt Buffalo National Park (Victoria, Australia)

    Report on the Grimwade Plant Collection of Percival St John and Botanical Exploration of Mt Buffalo National Park (Victoria, Australia) Alison Kellow Michael Bayly Pauline Ladiges School of Botany, The University of Melbourne July, 2007 THE GRIMWADE PLANT COLLECTION, MT BUFFALO Contents Summary ...........................................................................................................................3 Mt Buffalo and its flora.....................................................................................................4 History of botanical exploration........................................................................................5 The Grimwade plant collection of Percival St John..........................................................8 A new collection of plants from Mt Buffalo - The Miegunyah Plant Collection (2006/2007) ....................................................................................................................................13 Plant species list for Mt Buffalo National Park...............................................................18 Conclusion.......................................................................................................................19 Acknowledgments...........................................................................................................19 References .......................................................................................................................20 Appendix 1 Details of specimens in the Grimwade Plant Collection.............................22
  • Whitehorse Urban Biodiversity Strategy

    Whitehorse Urban Biodiversity Strategy

    WHITEHORSE URBAN BIODIVERSITY STRATEGY For Council managed open space, streetscapes and community facilities Whitehorse Urban Biodiversity Strategy for Council Managed Open Space, Streetscapes and Community Facilities Contents Acknowledgements 4 9.1.11 Ground Level Habitat/Coarse Woody 24 Executive Summary 5 Material Fuel Reduction Guidelines Glossary Of Terms 6 9.1.12 Expand the Existing Infill Tree Planting 24 Program to Improve Canopy Cover 1 Introduction 6 9.1.13 Biodiversity Research Liaison 24 Committee 2 What Is Biodiversity 8 2.1 Defining “Whitehorse Biodiversity” 8 9.2 New Biodiversity Actions: One-Off 25 2.2 What are Public Whitehorse 8 Commitments Biodiversity Assets? 9.2.1 Development of An Inventory of 25 2.3 Water and Biodiversity 8 Whitehorse Biodiversity Assets 3 Statutory Context 13 10 9.2.2 List of “Biodiversity Hotspots” 25 3.1 Whitehorse City Council Policies 10 9.2.3 Development of A Biodiversity 26 and Strategies Corridors Plan 9.2.4 Identify Potential “No Mow” Areas 26 4 The Whitehorse Landscape and Biodiversity 10 9.2.5 Vegetation Management Plans For 26 4.1 Aboriginal History of Whitehorse 10 Large Tracts Of Land With 4.2 Natural Landscape of Whitehorse 10 Alternative Uses 4.3 The Remaining Natural Landscape 12 9.2.6 Biodiversity Engagement – Logos 26 of Whitehorse and Signage 4.4 The Suburban Whitehorse 14 9.2.7 Development Of Monitoring 27 Landscape Program 4.5 What Biodiversity is Missing 14 9.2.8 Community Reporting and Data 27 From Whitehorse Gathering 4.6 What Whitehorse Biodiversity Remains 15 9.2.9 Environmental
  • Progress in the Recovery of the Flora of Treeless Subalpine Vegetation in Kosciuszko National Park After the 2003 Fires

    Progress in the Recovery of the Flora of Treeless Subalpine Vegetation in Kosciuszko National Park After the 2003 Fires

    Cunninghamia 8(4): 2004 Walsh & McDougall, Post-fire recovery of high mountain flora and vegetation 439 Progress in the recovery of the flora of treeless subalpine vegetation in Kosciuszko National Park after the 2003 fires Neville G. Walsh1 and Keith L. McDougall2 1National Herbarium of Victoria, Birdwood Avenue, South Yarra, Vic. 3141; 2NSW Department of Environment and Conservation, PO Box 2115, Queanbeyan, NSW AUSTRALIA 2620. Abstract: The fires of January 2003 burnt much of the treeless high mountain country of Victoria, New South Wales and the Australian Capital Territory, and were the first extensive conflagration of this area since 1939. For this reason there are remarkably few studies of the response of alpine plants and vegetation to fire. A flora survey of treeless subalpine vegetation in the Kosciuszko area in late 2002 sampled 215 sites. Of the 119 sites that were burnt, 60 were relocated and re-sampled in late 2003 to assess the mode and extent of regeneration in a range of treeless plant communities. Twenty-four species (including 3 exotics) were recorded only in the pre-fire sampling. Fifty species (including 18 exotics) were recorded only in the post-fire sampling. One species, Chenopodium erosum, had not previously been recorded in Kosciuszko National Park, and is believed to be the first native chenopod recorded in alpine vegetation in Australia. There was no significant difference in mean number of species per quadrat between pre-fire and post-fire quadrats. The average number of weeds per quadrat was, however, significantly greater post-fire. Most of this difference was attributable to the significantly greater number of weeds per quadrat in bog vegetation after the fire.
  • Noisettia Orchidiflora E Anchietea Pyrifolia: Isolamento, Caracterização E Avaliação De Atividades Biológicas

    Noisettia Orchidiflora E Anchietea Pyrifolia: Isolamento, Caracterização E Avaliação De Atividades Biológicas

    RESSALVA Atendendo solicitação do(a) autor(a), o texto completo desta tese será disponibilizado somente a partir de 10/03/2022. Antonio Fernández Bobey Ciclotídeos de Noisettia orchidiflora e Anchietea pyrifolia: Isolamento, caracterização e avaliação de atividades biológicas Tese apresentada ao Instituto de Química, Universidade Estadual Paulista Júlio de Mesquita Filho, como parte dos requisitos para a obtenção do título de Doutor em Química Orientadora: Profa. Dra.Vanderlan da Silva Bolzani Araraquara 2020 FICHA CATALOGRÁFICA Fernández Bobey, Antonio F363c Ciclotídeos das espécies Noisettia orchidiflora e Anchietea pyrifolia: isolamento, caracterização e avaliação das atividades biológicas / Antonio Fernández Bobey. – Araraquara: [s.n.], 2020 156 p.: il. Tese (doutorado) – Universidade Estadual Paulista, Instituto de Química Orientadora: Vanderlan da Silva Bolzani 1. Ciclotídeos. 2. Violaceae. 3. Espectrometria de massa. 4. LC-MS. 5. Peptídeos cíclicos. I. Título. Bibliotecária Responsável: Ana Carolina Gonçalves Bet – CRB8/8315 DADOS CURRICULARES Nome: Antonio Fernández Bobey Nome em citações bibliográficas: BOBEY, A. F.; FERNANDEZ-BOBEY, A. Nascimento: 14/03/1986 Naturalidade: La Habana/Cuba E-mail para contato: [email protected] Endereço profissional: Universidade Estadual Paulista Júlio de Mesquita Filho. Instituto de Química de Araraquara. Departamento de Química Orgânica (NuBBE). Rua Prof. Francisco Degni, 55. CEP: 14800-060. Araraquara/SP-Brasil. FORMAÇÃO ACADÊMICA Doutorado em Química UNESP- Universidade Estadual Paulista Júlio de Mesquita Filho, Araraquara/SP. Período: março 2016- fevereiro 2020. Título da tese: Ciclotídeos de Noisettia orchidiflora e Anchietea pyrifolia (Violaceae): Isolamento, caracterização e avaliação de atividades biológicas. Orientadora: Prof.a Dr.a Vanderlan da Silva Bolzani. Bolsa: CNPq (Processo 142286/2016-8). Mestrado em Química UNESP- Universidade Estadual Paulista Júlio de Mesquita Filho, Araraquara/SP.
  • A Broad Typology of Dry Rainforests on the Western Slopes of New South Wales

    A Broad Typology of Dry Rainforests on the Western Slopes of New South Wales

    A broad typology of dry rainforests on the western slopes of New South Wales Timothy J. Curran1,2, Peter J. Clarke1, and Jeremy J. Bruhl 1 1 Botany, Centre for Ecology, Evolution and Systematics, University of New England, Armidale NSW 2351, AUSTRALIA. 2 Author for correspondence. Current address: The School for Field Studies, Centre for Rainforest Studies, PO Box 141, Yungaburra, Queensland 4884, AUSTRALIA. [email protected] & [email protected] Abstract: Dry rainforests are those communities that have floristic and structural affinities to mesic rainforests and occur in parts of eastern and northern Australia where rainfall is comparatively low and often highly seasonal. The dry rainforests of the western slopes of New South Wales are poorly-understood compared to other dry rainforests in Australia, due to a lack of regional scale studies. This paper attempts to redress this by deriving a broad floristic and structural typology for this vegetation type. Phytogeographical analysis followed full floristic surveys conducted on 400 m2 plots located within dry rainforest across the western slopes of NSW. Cluster analysis and ordination of 208 plots identified six floristic groups. Unlike in some other regional studies of dry rainforest these groups were readily assigned to Webb structural types, based on leaf size classes, leaf retention classes and canopy height. Five community types were described using both floristic and structural data: 1)Ficus rubiginosa–Notelaea microcarpa notophyll vine thicket, 2) Ficus rubiginosa–Alectryon subcinereus–Notelaea microcarpa notophyll vine forest, 3) Elaeodendron australe–Notelaea microcarpa–Geijera parviflora notophyll vine thicket, 4) Notelaea microcarpa– Geijera parviflora–Ehretia membranifolia semi-evergreen vine thicket, and 5) Cadellia pentastylis low microphyll vine forest.
  • African Boxthorn National Best Practice Manual

    African Boxthorn National Best Practice Manual

    Weeds of National Significance African boxthorn National best practice manual Return to contents page 1 2 Return to contents page Weeds of National Significance African boxthorn National best practice manual Managing African boxthorn (Lycium ferocissimum) in Australia Produced and published by the Tasmanian Department of Primary Industries, Parks, Water and Environment with funding from the Australian Government Caring for Our Country program. This manual is sponsored by the Department of For copies of this manual contact: Agriculture, Fisheries and Forestry. Invasive Species Branch Department of Primary Industries, Parks, This manual is intended to provide information only Water and Environment on the subject matter under review. It is not intended PO Box 44 Hobart TAS 7001 to be, nor does it constitute, expert advice. Readers Phone: 1300 368 550 are warned against relying solely on the information contained in this manual. Further professional Manual compiled by the Weeds of National Significance advice should be sought before acting on any of the African Boxthorn National Coordinator in partnership information supplied in this manual. with the Australian Government, funded by Caring for Our Country. The Coordinator is hosted by Department While all care has been taken in the preparation of of Primary Industries, Parks, Water and Environment, this manual, neither the authors or the Crown in right Tasmania. Literature review performed using library of Tasmania, the Department of Primary Industries, catalogues, academic databases and internet searches. Parks, Water and Environment, nor their officers or This manual represents a rigorous review of African staff (collectively “the State”) accept any responsibility boxthorn biology and management in Australia.
  • Discovery of an Unusual Biosynthetic Origin for Circular Proteins in Legumes

    Discovery of an Unusual Biosynthetic Origin for Circular Proteins in Legumes

    Discovery of an unusual biosynthetic origin SEE COMMENTARY for circular proteins in legumes Aaron G. Potha,b, Michelle L. Colgraveb, Russell E. Lyonsb, Norelle L. Dalya, and David J. Craika,1 aInstitute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia; and bCommonwealth Scientific and Industrial Research Organisation Division of Livestock Industries, St. Lucia, Queensland 4067, Australia Edited by Sharon R. Long, Stanford University, Stanford, CA, and approved April 18, 2011 (received for review March 6, 2011) Cyclotides are plant-derived proteins that have a unique cyclic cystine knot topology and are remarkably stable. Their natural function is host defense, but they have a diverse range of pharma- ceutically important activities, including uterotonic activity and anti-HIV activity, and have also attracted recent interest as tem- plates in drug design. Here we report an unusual biosynthetic origin of a precursor protein of a cyclotide from the butterfly pea, Clitoria ternatea, a representative member of the Fabaceae plant family. Unlike all previously reported cyclotides, the domain corresponding to the mature cyclotide from this Fabaceae plant is embedded within an albumin precursor protein. We confirmed the expression and correct processing of the cyclotide encoded by the Cter M precursor gene transcript following extraction from C. ternatea leaf and sequencing by tandem mass spectrometry. Fig. 1. Structures and sequences of cyclotides. The structure of the proto- The sequence was verified by direct chemical synthesis and the typical cyclotide kB1 from O. affinis is illustrated. The conserved Cys residues peptide was found to adopt a classic knotted cyclotide fold as are labeled with Roman numerals and various loops in the backbone be- tween them are labeled loops 1–6.
  • The Bountiful Biological Activities of Cyclotides

    The Bountiful Biological Activities of Cyclotides

    [Downloaded free from http://www.cysonline.org on Monday, February 17, 2014, IP: 46.143.232.10] || Click here to download free Android application for this journal Review Article The bountiful biological activities of cyclotides Abstract Cyclotides are exceptionally stable circular peptides (28–37 amino acid residues) with a unique cyclic cystine knot (CCK) motif that were originally discovered through ethnobotanical investigations and bioassay‑directed natural products screenings. They have been isolated from four angiosperm families (Violaceae, Rubiaceae, Curcurbitaceae, and Fabaceae), and they exhibit a wide range of bioactivities including antibacterial/antimicrobial, nematocidal, molluscicidal, antifouling, insecticidal, antineurotensin, trypsin inhibiting, hemolytic, cytotoxic, antitumor, and anti‑HIV properties. Reports indicate that the mechanism of cyclotide bioactivity is the ability to target and interact with lipid membranes via the development of pores. Additionally, the nature of their surface‑exposed hydrophobic patch and CCK play integral roles in the potency of cyclotides. Their extraordinary stability and flexibility have recently allowed for the successful grafting of analogs with therapeutic properties onto their CCK framework. This achievement, coupled with the myriad of useful naturally occurring bioactivities displayed by cyclotides, makes them appealing candidates in drug design and crop management. Key words: Bioactivity, cancer, cyclotides, HIV, host defense Discovering Cyclotides although the decoction produced rapid deliveries, in some cases severe spasms ensued and emergency caesarian The discovery of cyclotides is attributed to ethnobotanical sections were required.[2-5] investigations and bioassay-directed screenings of potentially therapeutic plants. In 1965, a professor of Upon returning to his native country, Dr. Gran isolated Pharmacognosy at Uppsala University, Dr. Finn Sandberg, several polypeptides in samples of O.
  • Vegetation Inventory Report

    Vegetation Inventory Report

    Vegetation Inventory Report: ‘Radio’ property Melbourne Strategic Assessment © The State of Victoria Department of Environment, Land, Water and Planning 2020 This work is licensed under a Creative Commons Attribution 4.0 International licence. You are free to re-use the work under that licence, on the condition that you credit the State of Victoria as author. The licence does not apply to any images, photographs or branding, including the Victorian Coat of Arms, the Victorian Government logo and the Department of Environment, Land, Water and Planning (DELWP) logo. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ ISBN 978-1-76105-334-4 (online) Disclaimer This publication may be of assistance to you but the State of Victoria and its employees do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication. Accessibility If you would like to receive this publication in an alternative format, please telephone the DELWP Customer Service Centre on 136186, email [email protected], or via the National Relay Service on 133 677 www.relayservice.com.au. This document is also available on the internet at www.delwp.vic.gov.au. Contents Introduction .....................................................................................................................................................