1
|
Wang S, Wu K, Tang YJ, Deng H. Dehydroamino acid residues in bioactive natural products. Nat Prod Rep 2024; 41:273-297. [PMID: 37942836 PMCID: PMC10880069 DOI: 10.1039/d3np00041a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Indexed: 11/10/2023]
Abstract
Covering: 2000 to up to 2023α,β-Dehydroamino acids (dhAAs) are unsaturated nonproteinogenic amino acids found in a wide array of naturally occurring peptidyl metabolites, predominantly those from bacteria. Other organisms, such as fungi, higher plants and marine invertebrates, have also been found to produce dhAA-containing peptides. The α,β-unsaturation in dhAAs has profound effects on the properties of these molecules. They display significant synthetic flexibility, readily undergoing reactions such as Michael additions, transition-metal-catalysed cross-couplings, and cycloadditions. These residues in peptides/proteins also exhibit great potential in bioorthogonal applications using click chemistry. Peptides containing contiguous dhAA residues have been extensively investigated in the field of foldamers, self-assembling supermolecules that mimic biomacromolecules such as proteins to fold into well-defined conformations. dhAA residues in these peptidyl materials tend to form a 2.05-helix. As a result, stretches of dhAA residues arrange in an extended conformation. In particular, peptidyl foldamers containing β-enamino acid units display interesting conformational, electronic, and supramolecular aggregation properties that can be modulated by light-dependent E-Z isomerization. Among approximately 40 dhAAs found in the natural product inventory, dehydroalanine (Dha) and dehydrobutyrine (Dhb) are the most abundant. Dha is the simplest dehydro-α-amino acid, or α-dhAA, without any geometrical isomers, while its re-arranged isomer, 3-aminoacrylic acid (Aaa or ΔβAla), is the simplest dehydro-β-amino acid, or β-enamino acid, and displays E/Z isomerism. Dhb is the simplest α-dhAA that exhibits E/Z isomerism. The Z-isomer of Dhb (Z-Dhb) is sterically favourable and is present in the majority of naturally occurring peptides containing Dhb residues. Dha and Z-Dhb motifs are commonly found in ribosomally synthesized and post-translationally modified peptides (RiPPs). In the last decade, the formation of Dha and Dhb motifs in RiPPs has been extensively investigated, which will be briefly discussed in this review. The formation of other dhAA residues in natural products (NPs) is, however, less understood. In this review, we will discuss recent advances in the biosynthesis of peptidyl NPs containing unusual dhAA residues and cryptic dhAA residues. The proposed biosynthetic pathways of these natural products will also be discussed.
Collapse
Affiliation(s)
- Shan Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China.
| | - Kewen Wu
- Department of Chemistry, University of Aberdeen, Aberdeen AB24 3UE, UK.
| | - Ya-Jie Tang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China.
| | - Hai Deng
- Department of Chemistry, University of Aberdeen, Aberdeen AB24 3UE, UK.
| |
Collapse
|
2
|
Wang S, Fang Q, Lu Z, Gao Y, Trembleau L, Ebel R, Andersen JH, Philips C, Law S, Deng H. Discovery and Biosynthetic Investigation of a New Antibacterial Dehydrated Non‐Ribosomal Tripeptide. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202012902] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Shan Wang
- Marine Biodiscovery Centre Department of Chemistry University of Aberdeen Meston Walk Aberdeen AB24 3UE Scotland UK
| | - Qing Fang
- Marine Biodiscovery Centre Department of Chemistry University of Aberdeen Meston Walk Aberdeen AB24 3UE Scotland UK
| | - Zhou Lu
- Marine Biodiscovery Centre Department of Chemistry University of Aberdeen Meston Walk Aberdeen AB24 3UE Scotland UK
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application State Key Laboratory of Applied Microbiology Southern China Guangdong Institute of Microbiology Guangdong Academy of Sciences China
| | - Yingli Gao
- Marine Biodiscovery Centre Department of Chemistry University of Aberdeen Meston Walk Aberdeen AB24 3UE Scotland UK
- College of Marine Life and Fisheries Jiangsu Ocean University Lianyungang Jiangsu Province China
| | - Laurent Trembleau
- Marine Biodiscovery Centre Department of Chemistry University of Aberdeen Meston Walk Aberdeen AB24 3UE Scotland UK
| | - Rainer Ebel
- Marine Biodiscovery Centre Department of Chemistry University of Aberdeen Meston Walk Aberdeen AB24 3UE Scotland UK
| | | | - Carol Philips
- NCIMB Ltd. Ferguson Building, Craibstone Estate, Bucksburn Aberdeen AB21 9YA Scotland UK
| | - Samantha Law
- NCIMB Ltd. Ferguson Building, Craibstone Estate, Bucksburn Aberdeen AB21 9YA Scotland UK
| | - Hai Deng
- Marine Biodiscovery Centre Department of Chemistry University of Aberdeen Meston Walk Aberdeen AB24 3UE Scotland UK
| |
Collapse
|
3
|
Wang S, Fang Q, Lu Z, Gao Y, Trembleau L, Ebel R, Andersen JH, Philips C, Law S, Deng H. Discovery and Biosynthetic Investigation of a New Antibacterial Dehydrated Non-Ribosomal Tripeptide. Angew Chem Int Ed Engl 2020; 60:3229-3237. [PMID: 33107670 DOI: 10.1002/anie.202012902] [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: 09/24/2020] [Indexed: 11/07/2022]
Abstract
Dehydroalanine (Dha) and dehydrobutyrine (Dhb) display considerable flexibility in a variety of chemical and biological reactions. Natural products containing Dha and/or Dhb residues are often found to display diverse biological activities. While the (Z) geometry is predominant in nature, only a handful of metabolites containing (E)-Dhb have been found thus far. Here we report discovery of a new antimicrobial peptide, albopeptide, through NMR analysis and chemical synthesis, which contains two contiguous unsaturated residues, Dha-(E)-Dhb. It displays narrow-spectrum activity against vancomycin-resistant Enterococcus faecium. In-vitro biochemical assays show that albopeptide originates from a noncanonical NRPS pathway featuring dehydration processes and catalysed by unusual condensation domains. Finally, we provide evidence of the occurrence of a previously untapped group of short unsaturated peptides in the bacterial kingdom, suggesting an important biological function in bacteria.
Collapse
Affiliation(s)
- Shan Wang
- Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen, AB24 3UE, Scotland, UK
| | - Qing Fang
- Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen, AB24 3UE, Scotland, UK
| | - Zhou Lu
- Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen, AB24 3UE, Scotland, UK.,Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, China
| | - Yingli Gao
- Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen, AB24 3UE, Scotland, UK.,College of Marine Life and Fisheries, Jiangsu Ocean University, Lianyungang, Jiangsu Province, China
| | - Laurent Trembleau
- Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen, AB24 3UE, Scotland, UK
| | - Rainer Ebel
- Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen, AB24 3UE, Scotland, UK
| | | | - Carol Philips
- NCIMB Ltd., Ferguson Building, Craibstone Estate, Bucksburn, Aberdeen, AB21 9YA, Scotland, UK
| | - Samantha Law
- NCIMB Ltd., Ferguson Building, Craibstone Estate, Bucksburn, Aberdeen, AB21 9YA, Scotland, UK
| | - Hai Deng
- Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen, AB24 3UE, Scotland, UK
| |
Collapse
|
4
|
Nord C, Bjerketorp J, Levenfors JJ, Cao S, Strömstedt AA, Guss B, Larsson R, Hughes D, Öberg B, Broberg A. Isopedopeptins A-H: Cationic Cyclic Lipodepsipeptides from Pedobacter cryoconitis UP508 Targeting WHO Top-Priority Carbapenem-Resistant Bacteria. ACS Chem Biol 2020; 15:2937-2944. [PMID: 33054165 PMCID: PMC7684578 DOI: 10.1021/acschembio.0c00568] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
![]()
Pedobacter cryoconitis strain UP508 was isolated
from a soil sample using a mixture of ampicillin, kanamycin, and nalidixic
acid for selection. UP508 was found to produce >30 unknown antibacterial
peptides, of which eight, isopedopeptins A–H (1–8), were isolated by bioassay-guided fractionation
and characterized with respect to structures and biological properties.
Compounds 1–8 were all composed of
nine amino acid residues and one 3-hydroxy fatty acid residue, and
the structures were ring-closed via an ester bond from the C-terminal
aspartic acid to the 3-hydroxy fatty acid. The differences between
the peptides were the size and branching of the 3-hydroxy fatty acid
and the presence of a valine or a 3-hydroxyvaline residue. The isopedopeptins
mainly had activity against Gram-negative bacteria, and isopedopeptin
B (2), which had the best combination of antibacterial
activity, in vitro cytotoxicity, and hemolytic properties,
was selected for further studies against a larger panel of Gram-negative
bacteria. Isopedopeptin B was found to have good activity against
strains of WHO top-priority Gram-negative bacteria, i.e., carbapenem-resistant Acinetobacter baumannii, Escherichia coli, and Pseudomonas aeruginosa, with minimal inhibitory
concentrations (MIC) down to 1, 2, and 4 μg/mL, respectively.
Furthermore, compound 2 had activity against colistin-resistant
strains of A. baumannii, E. coli, and Klebsiella pneumoniae, with a MIC down to
8, 2, and 4 μg/mL, respectively. Compound 6 was
tested in an E. coli liposome system where it induced
significant leakage, indicating membrane disruption as one mechanism
involved in isopedopeptin antibacterial activity. Isopedopeptin B
stands out as a promising candidate for further studies with the goal
to develop a new antibiotic drug.
Collapse
Affiliation(s)
- Christina Nord
- Department of Molecular Sciences, Uppsala BioCentrum, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden
| | - Joakim Bjerketorp
- Department of Molecular Sciences, Uppsala BioCentrum, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden
- Ultupharma AB, Södra Rudbecksgatan 13, SE-752 36 Uppsala, Sweden
| | - Jolanta J. Levenfors
- Department of Molecular Sciences, Uppsala BioCentrum, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden
- Ultupharma AB, Södra Rudbecksgatan 13, SE-752 36 Uppsala, Sweden
| | - Sha Cao
- Department of Medical Biochemistry and Microbiology, Uppsala University, P.O. Box 582, SE-751 23 Uppsala, Sweden
| | - Adam A. Strömstedt
- Department of Medicinal Chemistry, Uppsala University, P.O. Box 574, SE-751 23 Uppsala, Sweden
| | - Bengt Guss
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, P.O. Box 7036, SE-750 07 Uppsala, Sweden
| | - Rolf Larsson
- Department of Medical Sciences, Uppsala University, SE-751 85 Uppsala, Sweden
| | - Diarmaid Hughes
- Department of Medical Biochemistry and Microbiology, Uppsala University, P.O. Box 582, SE-751 23 Uppsala, Sweden
| | - Bo Öberg
- Ultupharma AB, Södra Rudbecksgatan 13, SE-752 36 Uppsala, Sweden
- Department of Medicinal Chemistry, Uppsala University, P.O. Box 574, SE-751 23 Uppsala, Sweden
| | - Anders Broberg
- Department of Molecular Sciences, Uppsala BioCentrum, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden
| |
Collapse
|
5
|
Bouaïcha N, Miles CO, Beach DG, Labidi Z, Djabri A, Benayache NY, Nguyen-Quang T. Structural Diversity, Characterization and Toxicology of Microcystins. Toxins (Basel) 2019; 11:E714. [PMID: 31817927 PMCID: PMC6950048 DOI: 10.3390/toxins11120714] [Citation(s) in RCA: 206] [Impact Index Per Article: 41.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 12/02/2019] [Accepted: 12/04/2019] [Indexed: 11/22/2022] Open
Abstract
Hepatotoxic microcystins (MCs) are the most widespread class of cyanotoxins and the one that has most often been implicated in cyanobacterial toxicosis. One of the main challenges in studying and monitoring MCs is the great structural diversity within the class. The full chemical structure of the first MC was elucidated in the early 1980s and since then, the number of reported structural analogues has grown steadily and continues to do so, thanks largely to advances in analytical methodology. The structures of some of these analogues have been definitively elucidated after chemical isolation using a combination of techniques including nuclear magnetic resonance, amino acid analysis, and tandem mass spectrometry (MS/MS). Others have only been tentatively identified using liquid chromatography-MS/MS without chemical isolation. An understanding of the structural diversity of MCs, the genetic and environmental controls for this diversity and the impact of structure on toxicity are all essential to the ongoing study of MCs across several scientific disciplines. However, because of the diversity of MCs and the range of approaches that have been taken for characterizing them, comprehensive information on the state of knowledge in each of these areas can be challenging to gather. We have conducted an in-depth review of the literature surrounding the identification and toxicity of known MCs and present here a concise review of these topics. At present, at least 279 MCs have been reported and are tabulated here. Among these, about 20% (55 of 279) appear to be the result of chemical or biochemical transformations of MCs that can occur in the environment or during sample handling and extraction of cyanobacteria, including oxidation products, methyl esters, or post-biosynthetic metabolites. The toxicity of many MCs has also been studied using a range of different approaches and a great deal of variability can be observed between reported toxicities, even for the same congener. This review will help clarify the current state of knowledge on the structural diversity of MCs as a class and the impacts of structure on toxicity, as well as to identify gaps in knowledge that should be addressed in future research.
Collapse
Affiliation(s)
- Noureddine Bouaïcha
- Écologie, Systématique et Évolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, 91405 Orsay, France; (A.D.); (N.Y.B.)
| | - Christopher O. Miles
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford St, Halifax, NS B3H 3Z1, Canada; (C.O.M.); (D.G.B.)
| | - Daniel G. Beach
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford St, Halifax, NS B3H 3Z1, Canada; (C.O.M.); (D.G.B.)
| | - Zineb Labidi
- Laboratoire Biodiversité et Pollution des Écosystèmes, Faculté des Sciences de la Nature et de la Vie, Université Chadli Bendjedid d’El Taref, 36000 El Taref, Algeria;
| | - Amina Djabri
- Écologie, Systématique et Évolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, 91405 Orsay, France; (A.D.); (N.Y.B.)
- Laboratoire Biodiversité et Pollution des Écosystèmes, Faculté des Sciences de la Nature et de la Vie, Université Chadli Bendjedid d’El Taref, 36000 El Taref, Algeria;
| | - Naila Yasmine Benayache
- Écologie, Systématique et Évolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, 91405 Orsay, France; (A.D.); (N.Y.B.)
| | - Tri Nguyen-Quang
- Biofluids and Biosystems Modeling (BBML), Faculty of Agriculture, Dalhousie University, 39 Cox Road, Truro, B2N 5E3 Nova Scotia, Canada;
| |
Collapse
|
6
|
Ogipeptins, novel inhibitors of LPS: physicochemical properties and structural elucidation. J Antibiot (Tokyo) 2016; 70:84-89. [DOI: 10.1038/ja.2016.61] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 04/07/2016] [Accepted: 04/10/2016] [Indexed: 11/08/2022]
|
7
|
Puddick J, Prinsep MR, Wood SA, Cary SC, Hamilton DP, Holland PT. Further characterization of glycine-containing microcystins from the McMurdo dry Valleys of Antarctica. Toxins (Basel) 2015; 7:493-515. [PMID: 25675414 PMCID: PMC4344637 DOI: 10.3390/toxins7020493] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Accepted: 02/03/2015] [Indexed: 01/16/2023] Open
Abstract
Microcystins are hepatotoxic cyclic peptides produced by several cyanobacterial genera worldwide. In 2008, our research group identified eight new glycine-containing microcystin congeners in two hydro-terrestrial mat samples from the McMurdo Dry Valleys of Eastern Antarctica. During the present study, high-resolution mass spectrometry, amino acid analysis and micro-scale thiol derivatization were used to further elucidate their structures. The Antarctic microcystin congeners contained the rare substitution of the position-1 ᴅ-alanine for glycine, as well as the acetyl desmethyl modification of the position-5 Adda moiety (3S-amino-9S-methoxy-2S,6,8S-trimethyl-10-phenyldeca-4E,6E-dienoic acid). Amino acid analysis was used to determine the stereochemistry of several of the amino acids and conclusively demonstrated the presence of glycine in the microcystins. A recently developed thiol derivatization technique showed that each microcystin contained dehydrobutyrine in position-7 instead of the commonly observed N-methyl dehydroalanine.
Collapse
Affiliation(s)
| | - Michèle R Prinsep
- Department of Chemistry, School of Science, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand.
| | - Susanna A Wood
- Cawthron Institute, Private Bag 2, Nelson 7010, New Zealand.
- Environmental Research Institute, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand.
| | - Stephen Craig Cary
- Department of Biological Sciences, School of Science, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand.
| | - David P Hamilton
- Environmental Research Institute, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand.
| | | |
Collapse
|
8
|
Abstract
α,β-Dehydroamino acids are naturally occurring non-coded amino acids, found primarily in peptides. The review focuses on the type of α,β-dehydroamino acids, the structure of dehydropeptides, the source of their origin and bioactivity. Dehydropeptides are isolated primarily from bacteria and less often from fungi, marine invertebrates or even higher plants. They reveal mainly antibiotic, antifungal, antitumour, and phytotoxic activity. More than 60 different structures were classified, which often cover broad families of peptides. 37 different structural units containing the α,β-dehydroamino acid residues were shown including various side chains, Z and E isomers, and main modifications: methylation of peptide bond as well as the introduction of ester group and heterocycle ring. The collected data show the relation between the structure and bioactivity. This allows the activity of compounds, which were not studied in this field, but which belong to a larger peptide family to be predicted. A few examples show that the type of the geometrical isomer of the α,β-dehydroamino acid residue can be important or even crucial for biological activity.
Collapse
Affiliation(s)
- Dawid Siodłak
- Faculty of Chemistry, University of Opole, Oleska, 48 45-052, Opole, Poland,
| |
Collapse
|
9
|
High levels of structural diversity observed in microcystins from Microcystis CAWBG11 and characterization of six new microcystin congeners. Mar Drugs 2014; 12:5372-95. [PMID: 25402827 PMCID: PMC4245536 DOI: 10.3390/md12115372] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 10/21/2014] [Accepted: 10/23/2014] [Indexed: 01/18/2023] Open
Abstract
Microcystins (MCs) are cyclic peptides produced by cyanobacteria, which can be harmful to humans and animals when ingested. Differences in the coding of the non‑ribosomal peptide synthetase/polyketide synthase enzyme complex responsible for microcystin production have resulted in more than 100 microcystin variants being reported to date. The microcystin diversity of Microcystis CAWBG11 was investigated using matrix-assisted laser desorption/ionization-time of flight mass spectrometry and liquid chromatography-mass spectrometry. This revealed that CAWBG11 simultaneously produced 21 known microcystins and six new congeners: [Asp3] MC-RA, [Asp3] MC-RAba, [Asp3] MC-FA, [Asp3] MC-WA, MC-FAba and MC-FL. The new congeners were putatively characterized by tandem mass spectrometry and chemical derivatization. A survey of the microcystin congeners produced by 49 cyanobacterial strains documented in scientific literature showed that cyanobacteria generally produce four microcystin congeners, but strains which produce up to 47 microcystin congeners have been reported. Microcystis CAWBG11 (which produces at least 27 congeners) was positioned in the top ten percentile of the strains surveyed, and showed fluidity of the amino acids incorporated into both position two and position four.
Collapse
|
10
|
Niedermeyer THJ, Daily A, Swiatecka-Hagenbruch M, Moscow JA. Selectivity and potency of microcystin congeners against OATP1B1 and OATP1B3 expressing cancer cells. PLoS One 2014; 9:e91476. [PMID: 24614281 PMCID: PMC3948918 DOI: 10.1371/journal.pone.0091476] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 02/13/2014] [Indexed: 11/19/2022] Open
Abstract
Microcystins are potent phosphatase inhibitors and cellular toxins. They require active transport by OATP1B1 and OATP1B3 transporters for uptake into human cells, and the high expression of these transporters in the liver accounts for their selective hepatic toxicity. Several human tumors have been shown to have high levels of expression of OATP1B3 but not OATP1B1, the main transporter in liver cells. We hypothesized that microcystin variants could be isolated that are transported preferentially by OATP1B3 relative to OATP1B1 to advance as anticancer agents with clinically tolerable hepatic toxicity. Microcystin variants have been isolated and tested for cytotoxicity in cancer cells stably transfected with OATP1B1 and OATP1B3 transporters. Microcystin variants with cytotoxic OATP1B1/OATP1B3 IC50 ratios that ranged between 0.2 and 32 were found, representing a 150-fold range in transporter selectivity. As microcystin structure has a significant impact on transporter selectivity, it is potentially possible to develop analogs with even more pronounced OATP1B3 selectivity and thus enable their development as anticancer drugs.
Collapse
Affiliation(s)
- Timo H. J. Niedermeyer
- Cyano Biotech GmbH, Berlin, Germany
- Interfaculty Institute for Microbiology and Infection Medicine, University of Tübingen, Tübingen, Germany
- * E-mail:
| | - Abigail Daily
- Department of Pediatrics, University of Kentucky, Lexington, Kentucky, United States of America
| | | | - Jeffrey A. Moscow
- Department of Pediatrics, University of Kentucky, Lexington, Kentucky, United States of America
| |
Collapse
|
11
|
Kim HJ, Choi HS, Yang SY, Kim IS, Yamaguchi T, Sohng JK, Park SK, Kim JC, Lee CH, Gardener BM, Kim YC. Both extracellular chitinase and a new cyclic lipopeptide, chromobactomycin, contribute to the biocontrol activity of Chromobacterium sp. C61. MOLECULAR PLANT PATHOLOGY 2014; 15:122-132. [PMID: 24033929 PMCID: PMC6638690 DOI: 10.1111/mpp.12070] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Chromobacterium sp. strain C61 displays antifungal activities in vitro and has been used successfully for the biocontrol of plant diseases under field conditions. In this study, the roles of extracellular chitinase and an antifungal compound produced by strain C61 were investigated to elucidate their contributions to biological control activity. The bacterium possessed a locus chi54 encoding an extracellular chitinase, and mutation of chi54 eliminated chitinase production. Production of the extracellular enzyme and expression of the chi54 transcript were increased in the wild-type strain when chitin was added to the culture medium. In vitro assays showed that purified chitinase inhibited spore germination of multiple pathogens. However, the in planta biocontrol activity of filtrates of cultures grown in the presence of chitin was lower than that of filtrates grown without chitin, indicating that correlation between chitinase and biocontrol activity was lacking. The analysis of C61 culture filtrates revealed an antifungal cyclic lipopeptide, chromobactomycin, whose structure contained a unique nonameric peptide ring. The purified chromobactomycin inhibited the growth of several phytopathogenic fungi in vitro, and plant application significantly reduced disease severity for several pathogens. Furthermore, the production of chromobactomycin was reduced in cultures amended with chitin. These data suggest that the production of both the extracellular chitinase Chi54 and the newly identified antibiotic chromobactomycin can contribute, in an interconnected way, to the suppression of plant disease by Chromobacterium sp. strain C61.
Collapse
Affiliation(s)
- Hyun Jung Kim
- Institute of Environmentally-Friendly Agriculture, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, 500-757, South Korea
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Bortoli S, Volmer DA. Account: characterization and identification of microcystins by mass spectrometry. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2014; 20:1-19. [PMID: 24881451 DOI: 10.1255/ejms.1250] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In this brief overview, the authors describe mass spectral techniques for the detection and identification of microcystin toxins. Microcystins are secondary metabolites produced by cyanobacteria. Determination of these toxic compounds and discovery of new variants is very important as they pose a great danger to the human food chain. Cyanobacterial blooms frequently occur in many areas worldwide and have the potential to contaminate the water via cyanotoxin release, especially microcystins. Among the various analytical techniques used for analysis, mass spectrometry has become the most important method as it allows simultaneous quantification and structural characterization of multiple microcystin variants. This brief overview article focuses on mass spectrometry techniques for identification of microcystins, including ionization methods, mass spectral fragmentation routes, profiling techniques, tandem and high-resolution mass spectrometry as well as typing of cyanobacterial strains.
Collapse
|
13
|
Pedopeptins, novel inhibitors of LPS: taxonomy of producing organism, fermentation, isolation, physicochemical properties and structural elucidation. J Antibiot (Tokyo) 2013; 67:243-51. [PMID: 24301185 DOI: 10.1038/ja.2013.122] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 08/29/2013] [Accepted: 09/13/2013] [Indexed: 11/08/2022]
Abstract
In the course of our screening for inhibitors of lipopolysaccharide (LPS) binding to cellular receptor CD14, potent inhibitory activity was detected in the cultured broth of Pedobacter sp. SANK 72003. Three active compounds, pedopeptin A, B and C, were isolated from the broth and their structures were elucidated by physicochemical and spectral data to be new cyclic depsipeptides.
Collapse
|
14
|
Ostermaier V, Christiansen G, Schanz F, Kurmayer R. Genetic variability of microcystin biosynthesis genes in Planktothrix as elucidated from samples preserved by heat desiccation during three decades. PLoS One 2013; 8:e80177. [PMID: 24265798 PMCID: PMC3827215 DOI: 10.1371/journal.pone.0080177] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 10/09/2013] [Indexed: 11/23/2022] Open
Abstract
Historic samples of phytoplankton can provide information on the abundance of the toxigenic genotypes of cyanobacteria in dependence on increased or decreased eutrophication. The analysis of a time-series from preserved phytoplankton samples by quantitative PCR (qPCR) extends observation periods considerably. The analysis of DNA from heat-desiccated samples by qPCR can be aggravated by point substitutions or the fragmentation of DNA introduced by the high temperature. In this study, we analyzed whether the heat desiccation of the cellular material of the cyanobacterium Planktothrix sp. introduced potential errors to the template DNA that is used for qPCR within (i) 16S rDNA and phycocyanin genes and (ii) the mcyA gene indicative of the incorporation of either dehydrobutyrine (Dhb) or N-methyl-dehydroalanine (Mdha) in position 7, and (ii) the mcyB gene, which is indicative of homotyrosine (Hty) in position 2 of the microcystin (MC) molecule. Due to high temperature desiccation, the deterioration of the DNA template quality was rather due to fragmentation than due to nucleotide substitutions. By using the heat-desiccated samples of Lake Zürich, Switzerland the abundance of the Dhb, Mdha and Hty genotypes was determined during three decades (1977-2008). Despite major changes in the trophic state of the lake resulting in a major increase of the total Planktothrix population density, the proportion of these genotypes encoding the synthesis of different MC congeners showed high stability. Nevertheless, a decline of the most abundant mcyA genotype indicative of the synthesis of Dhb in position 7 of the MC molecule was observed. This decline could be related to the gradual incline in the proportion of a mutant genotype carrying a 1.8kbp deletion of this gene region. The increase of this mcyA (Dhb) gene deletion mutant has been minor so far, however, and likely did not affect the overall toxicity of the population.
Collapse
Affiliation(s)
| | | | - Ferdinand Schanz
- Limnological Station, Institute of Plant Biology, University of Zürich, Kilchberg, Switzerland
| | - Rainer Kurmayer
- Research Institute for Limnology, University of Innsbruck, Mondsee, Austria
- * E-mail:
| |
Collapse
|
15
|
Miles CO, Sandvik M, Haande S, Nonga H, Ballot A. LC-MS analysis with thiol derivatization to differentiate [Dhb(7)]- from [Mdha(7)]-microcystins: analysis of cyanobacterial blooms, Planktothrix cultures and European crayfish from Lake Steinsfjorden, Norway. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:4080-4087. [PMID: 23531156 DOI: 10.1021/es305202p] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Kinetic studies showed that [Asp(3), Dhb(7)]MC-RR reacted with mercaptoethanol hundreds of times more slowly than MC-RR and a range of other [Mdha(7)]-containing microcystin congeners. The difference in reaction rate was sufficiently large that derivatization of microcystin-containing samples with mercaptoethanol, followed by LC-MS analysis, clearly discriminated between microcystins containing the isobaric [Dhb(7)]- and [Mdha(7)]-groups. Application of this approach, using LC-MS with both-ion trap and triple-quadrupole mass spectrometers, to water samples and Planktothrix cultures from Lake Steinsfjorden, Norway, demonstrated the presence of [Asp(3), Dhb(7)]MC-RR (5), [Asp(3)]MC-RY (14), and [Asp(3)]MC-LY (16), as well as analogues tentatively identified as [Asp(3)]MC-RR (4), [Asp(3), DMAdda(5), Dhb(7)]MC-LR (6), [Asp(3), Dhb(7)]MC-HtyR (8), [Asp(3)]MC-HtyR (9), [Asp(3), Dhb(7)]MC-LR (10), [Asp(3)]MC-LR (11), [Asp(3), Dhb(7)]MC-RY (15), and [Asp(3), Dhb(7)]MC-LY (17), together with low levels of several other analogues. This is the first use of this thiol-based LC-MS approach to identify Dhb-containing microcystins, and allowed identification of LC-MS peaks in a mixture of [Mdha(7)]- and [Dhb(7)]-congeners of [Asp(3)]MC-RR (4, 5), -RY (14, 15), and -LY (16, 17) in the samples from L. Steinsfjorden. This is also the first report of MC-RY-congeners outside of Africa, or in Planktothrix spp. Analysis of European crayfish (Astacus astacus) taken from L. Steinsfjorden revealed the presence of only trace levels of microcystins in the edible parts.
Collapse
|
16
|
Mil’man BL, Russkikh YV, Nekrasova LV, Zhakovskaya ZA. An approach to the mass spectrometry identification of cyanobacterial peptides. The case of demethylmicrocystin-LR. JOURNAL OF ANALYTICAL CHEMISTRY 2011. [DOI: 10.1134/s1061934811140127] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
17
|
del Campo FF, Ouahid Y. Identification of microcystins from three collection strains of Microcystis aeruginosa. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2010; 158:2906-2914. [PMID: 20619941 DOI: 10.1016/j.envpol.2010.06.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Revised: 05/30/2010] [Accepted: 06/09/2010] [Indexed: 05/29/2023]
Abstract
Microcystins (MCs) are toxic cyclic heptapeptides produced by various cyanobacteria genera, especially Microcystis. We identified 10 out of 12 MCs produced by three Microcystis aeruginosa strains from cyanobacteria collections, UTEX 2666, UTEX 2670 and UAM 1303, by using two analytical methods: Matrix-assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF/MS) and HPLC Photodiode Array Detector coupled to a hybrid Quadrupole Time of Flight Mass Spectrometry (HPLC-PDA-QTOF/MS). MALDI-TOF/MS failed to detect non-polar MCs, such as MC-LY and MC-LW. HPLC-QTOF/MS permitted the accurate identification of most MCs present in methanolic extracts. Besides, three new MCs, namely: [D-Glu(OCH3)6, D-Asp3] MC-LAba, MC-YL and MC-YM were detected by HPLC-QTOF/MS.
Collapse
Affiliation(s)
- Francisca F del Campo
- Departamento de Biología, Universidad Autónoma de Madrid, Cantoblanco, 28049-Madrid, Spain
| | | |
Collapse
|
18
|
Sepe V, D’Auria MV, Bifulco G, Ummarino R, Zampella A. Concise synthesis of AHMHA unit in perthamide C. Structural and stereochemical revision of perthamide C. Tetrahedron 2010. [DOI: 10.1016/j.tet.2010.07.060] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
19
|
Festa C, De Marino S, Sepe V, Monti MC, Luciano P, D'Auria MV, Débitus C, Bucci M, Vellecco V, Zampella A. Perthamides C and D, two new potent anti-inflammatory cyclopeptides from a Solomon Lithistid sponge Theonella swinhoei. Tetrahedron 2009. [DOI: 10.1016/j.tet.2009.10.026] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
20
|
Krüger T, Christian B, Luckas B. Development of an analytical method for the unambiguous structure elucidation of cyclic peptides with special appliance for hepatotoxic desmethylated microcystins. Toxicon 2009; 54:302-12. [PMID: 19397919 DOI: 10.1016/j.toxicon.2009.04.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Revised: 04/14/2009] [Accepted: 04/15/2009] [Indexed: 10/20/2022]
Abstract
The periodical occurrence of harmful algal blooms (HABs) in freshwater lakes requires the determination of potential cyanobacterial toxins, especially microcystins (MCs). On demand of an adequate risk assessment, the high diversity of these hepatotoxic cyclic heptapeptides implicates the need of an unambiguous detection of their specific structural variants. Therefore, LC-MS and LC-MS/MS methods are the approaches of choice for determination of MCs. In contrast, even tandem mass spectromic fragmentation patterns are not even sufficient in any kind of structural determination requirements, whereas NMR methods require very high amounts of MCs. In this study, we present a novel method for chromatographic separation of desmethylated microcystins (dm-MCs). Based on the isolation of the specific structural variants using semi-preparative HPLC, a method was developed for the structure elucidation of cyclic peptides with special appliance for the determination of dm-MCs via analysis of the specific amino acid composition after peptide hydrolysis followed by stereospecific detection of the amino acids and resulting keto acids. On the basis of this method it is demonstrated that dm-MC-RR with the structure [Dha(7)]MC-RR represented the major compound in the microcystin pattern of Microcystis aeruginosa bloom events in 2005 and 2006 in Lake Senftenberg, Germany.
Collapse
Affiliation(s)
- Thomas Krüger
- Department of Food Chemistry, Friedrich-Schiller-University of Jena, Institute of Nutrition, 07743 Jena, Germany.
| | | | | |
Collapse
|
21
|
Schmidtkunz C, Bernd Stich H, Welsch T. Improving the Selectivity and Confidence in the HPLC Analysis of Microcystins in Lake Sediments. J LIQ CHROMATOGR R T 2009. [DOI: 10.1080/10826070902767999] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Christoph Schmidtkunz
- a Institute of Analytical and Environmental Chemistry , Ulm University , Ulm, Germany
| | - Hans Bernd Stich
- b Institute for Lake Research–State Institute for Environment, Measurement and Nature Conservation Baden-Württemberg , Langenargen, Germany
| | - Thomas Welsch
- a Institute of Analytical and Environmental Chemistry , Ulm University , Ulm, Germany
| |
Collapse
|
22
|
Nandel FS, Sahrawat TR. Conformational study of poly-ΔAbu peptides and construction of amphipathic nanostructure. Biopolymers 2009; 92:44-51. [DOI: 10.1002/bip.21118] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
23
|
Christiansen G, Yoshida WY, Blom JF, Portmann C, Gademann K, Hemscheidt T, Kurmayer R. Isolation and structure determination of two microcystins and sequence comparison of the McyABC adenylation domains in Planktothrix species. JOURNAL OF NATURAL PRODUCTS 2008; 71:1881-6. [PMID: 18939865 PMCID: PMC3080429 DOI: 10.1021/np800397u] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Microcystins (MCs) are toxic heptapeptides found in cyanobacteria and share the common structure cyclo(-d-Ala(1)-l-X(2)-d-isoMeAsp(3)-l-Z(4)-Adda(5)-d-isoGlu(6)-Mdha(7)). The letters X and Z in the general formula above represent a wide range of l-amino acids that occupy positions 2 and 4, respectively. In general the variation in structural variants is due to the exchange of amino acids in position 7, 2, and 4. In the present work we report two homotyrosine (Hty)-containing microcystin variants, [d-Asp(3),(E)-Dhb(7)]-MC-HtyY (1) and [d-Asp(3),(E)-Dhb(7)]-MC-HtyHty (2), which were isolated from strain No80 of Planktothrix rubescens. Their structures were elucidated using amino acid analysis as well as 1D and 2D NMR techniques. The adenylation domains of McyABC involved in amino acid activation in positions 7, 2, and 4 of the microcystin molecule, respectively, were compared with corresponding genes of Planktothrix strain CYA126/8 producing [d-Asp(3),Mdha(7)]-MC-RR and [d-Asp(3),Mdha(7)]-MC-LR. While the adenylation domain comparison of McyAB between the two Planktothrix strains revealed considerable DNA recombination, the adenylation domain of McyC showed only a single amino acid substitution, which was correlated with the replacement of Arg by Hty in position 4 of the microcystin molecule.
Collapse
Affiliation(s)
- Guntram Christiansen
- Austrian Academy of Sciences, Institute for Limnology, Mondseestraße 9, A-5310 Mondsee, Austria
| | - Wesley Y. Yoshida
- University of Hawaii at Manoa, Department of Chemistry, 2545 McCarthy Hall, Honolulu, HI 96822
| | - Judith F. Blom
- Limnological Station, Institute of Plant Biology, University of Zürich, CH-8802 Kilchberg, Switzerland
| | - Cyril Portmann
- Chemical Synthesis Laboratory, SB-ISIC-LSYNC, Swiss Federal Institute of Technology (EPFL), CH-1015 Lausanne, Switzerland
| | - Karl Gademann
- Chemical Synthesis Laboratory, SB-ISIC-LSYNC, Swiss Federal Institute of Technology (EPFL), CH-1015 Lausanne, Switzerland
- To whom correspondence should be addressed. Tel: ++41 21 6939315. Fax ++41 21 693 97 00. (K.G.). Tel: ++43 6232 3125 32. Fax: ++43 6232 3578. (R.K.)
| | - Thomas Hemscheidt
- University of Hawaii at Manoa, Department of Chemistry, 2545 McCarthy Hall, Honolulu, HI 96822
| | - Rainer Kurmayer
- Austrian Academy of Sciences, Institute for Limnology, Mondseestraße 9, A-5310 Mondsee, Austria
- To whom correspondence should be addressed. Tel: ++41 21 6939315. Fax ++41 21 693 97 00. (K.G.). Tel: ++43 6232 3125 32. Fax: ++43 6232 3578. (R.K.)
| |
Collapse
|
24
|
Ersmark K, Del Valle J, Hanessian S. Aeruginosine: Chemie und Biologie der Serinprotease-Inhibitoren. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200605219] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
25
|
Ersmark K, Del Valle J, Hanessian S. Chemistry and Biology of the Aeruginosin Family of Serine Protease Inhibitors. Angew Chem Int Ed Engl 2008; 47:1202-23. [DOI: 10.1002/anie.200605219] [Citation(s) in RCA: 146] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
|
26
|
Affiliation(s)
- Stephanie Grond
- Georg-August Universität Göttingen, Institute of Organic and Biomolecular Chemistry, Tammannstr. 2, D-37077, Göttingen.
| | | |
Collapse
|
27
|
Hoeger SJ, Schmid D, Blom JF, Ernst B, Dietrich DR. Analytical and functional characterization of microcystins [Asp3]MC-RR and [Asp3,Dhb7]MC-RR: consequences for risk assessment? ENVIRONMENTAL SCIENCE & TECHNOLOGY 2007; 41:2609-16. [PMID: 17438823 DOI: 10.1021/es062681p] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The microcystin (MC) producing P. rubescens occurs in pre-alpine lakes and may impact fishery success, bathing, and raw water quality. P. rubescens extracts, characterized via LC-MS, contained the two MC-RR variants [Asp3]MC-RR and [Asp3,Dhb7]MC-RR. The protein-phosphatase-inhibition assay (cPPIA with phosphatases 1 and 2A) in its capability to quantify [Asp3]MC-RR, [Asp3,Dhb7]MC-RR, and MC-RR was compared to HPLC-DAD and anti-Adda-ELISA. The IC50 values (PP1 and PP2A) determined for MC-LR, MC-RR, and [Asp3]MC-RR were in the same range (1.9-3.8 and 0.45-0.75 nM). A 50-fold higher concentration of [Asp3,Dhb7]MC-RR (29.8 nM) was necessary to inhibit the PP2A by 50%. The PP1-IC50 of [Asp3,Dhb7]MC-RR was 22-fold higher (56.4 nM) than those of the other MCs, suggesting that specific structural characteristics are responsible for its weaker PPI capacity. Western blots demonstrated that [Asp3,Dhb7]MC-RR does not covalently bind to PP1. [Asp3,Dhb7]MC-RR has comparable in vivo LD50 values to MC-RR, despite a far lower PP-inhibiting capacity, suggesting that toxicodynamic and toxicokinetic characteristics of [Asp3,Dhb7]MC-RR are responsible for its high in vivo toxicity. The data demonstrate that cPPIA analysis of [Asp3,Dhb7]MC-RR-containing samples prevent reliable MC determination and lead to underestimation of potential toxicity.
Collapse
Affiliation(s)
- S J Hoeger
- Environmental Toxicology, University of Konstanz, Germany
| | | | | | | | | |
Collapse
|
28
|
Messineo V, Mattei D, Melchiorre S, Salvatore G, Bogialli S, Salzano R, Mazza R, Capelli G, Bruno M. Microcystin diversity in a Planktothrix rubescens population from Lake Albano (Central Italy). Toxicon 2006; 48:160-74. [PMID: 16828137 DOI: 10.1016/j.toxicon.2006.04.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2005] [Revised: 04/03/2006] [Accepted: 04/07/2006] [Indexed: 11/15/2022]
Abstract
The cyanobacterium Planktothrix rubescens Anagnostidis & Komarek (previously Oscillatoria rubescens DC ex Gomont) is present in several Italian lakes and it is known to produce cyanotoxins. The dynamics and toxin production of P. rubescens population in Lake Albano, a volcanic crater lake in Central Italy, has been studied for 5 years (January 2001-April 2005). Winter-spring superficial blooms with frequent scums were observed every year. Total microcystin (MC) levels were measured from April 2004 to October 2005 by liquid chromatography-tandem mass spectrometry. MC levels up to 14.2mug/l were measured, with high concentrations found in summer at a 20-25m depth. The intracellular toxin content varied between 1.5 (surface, January 2004) and 0.21pg/cell (surface, May 2004). Six different MCs were detected, the most abundant being two desmethyl-MC-RR isomers. Of the 13 water wells monitored in the Lake Albano area, two of them showed MC contamination during winter, confirming the ability of these toxins to migrate through groundwater towards public water sources. These results highlight the need for further studies on the mobility and fate of these pervasive cyanobacterial toxins.
Collapse
Affiliation(s)
- V Messineo
- Department of Environment and Primary Prevention, National Institute of Health, viale Regina Elena, 299-00161, Rome, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Ott JL, Carmichael WW. LC/ESI/MS method development for the analysis of hepatotoxic cyclic peptide microcystins in animal tissues. Toxicon 2006; 47:734-41. [PMID: 16626770 DOI: 10.1016/j.toxicon.2006.01.025] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2005] [Revised: 01/20/2006] [Accepted: 01/20/2006] [Indexed: 11/26/2022]
Abstract
Microcystins (MCYSTs) are a family of related cyclic heptapeptides produced by several genera and species of blue-green algae (cyanobacteria). MCYSTs are potent and specific inhibitors of the serine threonine family of protein phosphatases, especially PP1 and PP2A. MCYSTs inhibit a liver's protein phosphatase by forming a covalent linkage between MCYSTs' Mdha residue and the phosphatase's cysteine residue. Due to the covalent linkage, analysis of MCYSTs in animal tissues has been limited to determination of unbound MCYST concentration. The MMPB (2-methyl-3-methoxy-4-phenylbutyric acid) oxidation procedure allows for the detection of total MCYST burden by releasing the carboxylic acid MMPB from MCYST's Adda amino acid. An internal standard 4-phenylbutyric acid (4PB) accounts for losses during the method. LC/MS conditions were developed using a ThermoFinnigan LCQDuo ion trap in negative electrospray ionization (ESI). Since both compounds produce the [M-H](-) ion, analysis occurs in selected ion monitoring (SIM) mode for both MMPB (m/z 207.1) and 4PB (m/z 163.1). Complete oxidation of MCYST-LR in liver tissues occurs in 3h. A solid phase extraction (SPE) cartridge removes MMPB and 4PB from the oxidant solution. The process efficiency for the SPE procedure is only 51.3%; however, suppression experiments indicate a 41.8% loss in signal strength due to matrix interferences. Therefore, the extraction efficiency for the SDB-XC cartridge procedure is 93.1%. This research has been successful in developing an LC/MS method for the analysis of total MCYST burden in animal tissues.
Collapse
Affiliation(s)
- Jennifer L Ott
- Department of Biological Sciences, Wright State University, 3640 Colonel Glenn Highway, Dayton, OH 45435, USA
| | | |
Collapse
|
30
|
Broda MA, Ciszak EM, Koziol AE, Pietrzynski G, Rzeszotarska B. Conformational investigation of α,β-dehydropeptides. XVI. β-turn tendency in Ac-Pro-ΔXaa-NHMe: crystallographic and theoretical studies. J Pept Sci 2006; 12:538-49. [PMID: 16733828 DOI: 10.1002/psc.763] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The crystal structures of two diastereomeric alpha,beta-dehydrobutyrine peptides Ac-Pro-(Z)-DeltaAbu-NHMe (I) and Ac-Pro-(E)-DeltaAbu-NHMe (II) have been determined. Both dehydropeptides adopt betaI-turn conformation characterized by the pairs of (phi(i+1), psi(i+1)) and (phi(i+2), psi(i+2)) angles as -66, -19, -97, 11 degrees for I and -59, -27, -119, 29 degrees for II. In each peptide, the betaI turn is stabilized by (i + 3) --> i intramolecular hydrogen bonds with N...O distance of 3.12 A for I and 2.93 A for II. These structures have been compared to the crystal structures of homologous peptides Ac-Pro-DeltaVal-NHMe and Ac-Pro-DeltaAla-NHMe. Theoretical analyses by DFT/B3LYP/6-31 + G** method of conformers formed by these four peptides and by the saturated peptide Ac-Pro-Ala-NHMe revealed that peptides with a (Z) substituent at the C(beta) (i+2) atom of dehydroamino acid, i.e. Ac-Pro-DeltaVal-NHMe and Ac-Pro-(Z)-DeltaAbu-NHMe, predominantly form beta turns, both in vacuo and in polar environment. The tendency to adopt beta-turn conformation is much weaker for the peptides lacking the (Z) substituent, Ac-Pro-(E)-DeltaAbu-NHMe and Ac-Pro-DeltaAla-NHMe. The latter adopts a semi-extended or an extended conformation in every polar environment, including a weakly polar solvent. The saturated peptide Ac-Pro-Ala-NHMe in vacuo prefers a beta-turn conformation, but in polar environment the differences between various conformers are small. The role of pi-electron correlation and intramolecular hydrogen bonds interaction in stabilizing the hairpin structures are discussed.
Collapse
Affiliation(s)
- Malgorzata A Broda
- Institute of Chemistry, University of Opole, Olesja Street 48, 45-052 Opole, Poland.
| | | | | | | | | |
Collapse
|
31
|
Hicks LM, Moffitt MC, Beer LL, Moore BS, Kelleher NL. Structural characterization of in vitro and in vivo intermediates on the loading module of microcystin synthetase. ACS Chem Biol 2006; 1:93-102. [PMID: 17163649 DOI: 10.1021/cb500007v] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The microcystin family of toxins is the most common cause of hepatotoxicity associated with water blooms of cyanobacterial genera. The biosynthetic assembly line producing the toxic cyclic peptide, microcystin, contains an adenylation-peptidyl carrier protein didomain (A-PCP) at the N-terminus of the initiator module McyG (295 kDa) that has been postulated to activate and load the starter unit phenylacetate for formation of the unusual aromatic beta-amino acid residue, Adda, before subsequent extension. Characterization of the McyG A-PCP didomain (78 kDa) using ATP-PP i exchange assays and mass spectrometry revealed that assorted phenylpropanoids are preferentially activated and loaded onto the PCP carrier domain rather than phenylacetate itself. For the first time, thioesters formed in vivo were detected directly using large molecule mass spectrometry. Additionally substrates were cleaved using a type II thioesterase for structural elucidation by small molecule mass spectrometry. Unprecedented features of the McyG A-PCP didomain include the in vivo acylation of the holo PCP with exogenous and endogenous substrates, along with the ability of the apo protein to retain the acyl-AMP intermediate during affinity purification. These results imply that phenylpropanoids are preferentially loaded onto the McyG PCP; however one carbon must be excised following extension of the starter unit with malonyl-CoA in order to generate the expected polyketide chain which leads us to ponder the novel biochemistry by which this occurs.
Collapse
Affiliation(s)
- Leslie M Hicks
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | | | | | | | | |
Collapse
|
32
|
Mazur-Marzec H, Meriluoto J, Pliński M, Szafranek J. Characterization of nodularin variants in Nodularia spumigena from the Baltic Sea using liquid chromatography/mass spectrometry/mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2006; 20:2023-32. [PMID: 16755614 DOI: 10.1002/rcm.2558] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Nodularin is a potent hepatotoxic cyclic pentapeptide produced by planktonic cyanobacterium Nodularia spumigena. Bloom and culture samples of the cyanobacterium collected and isolated from the Gulf of Gdańsk, southern Baltic Sea, were analyzed. Hybrid quadrupole-time-of-flight liquid chromatography/mass spectrometry/mass spectrometry (TOF-LC/MS/MS) with ionspray (ISP) and collision-induced dissociation (CID) were used to characterize nodularin and its analogues. The identification process was based on the comparison of recorded product ion spectra with the previously reported FAB-MS/CID (high-energy) mass spectra of the corresponding nodularin variants. Amino acid structures and sequences were derived from the fragmentation pattern of the [M+H](+) ions. Apart from unmodified nodularin with an arginine residue (NOD-R), three demethylated variants have been found. The sites of demethylation were located on aspartic acid [Asp(1)]NOD, the Adda residue [DMAdda(3)]NOD, and dehydrobutyric acid [dhb(5)]NOD. In two other nodularin variants an additional methyl group is located in the Adda [MeAdda]NOD and Glu [Glu(4)(OMe)]NOD residues. The linear NOD and the geometrical isomer of NOD-R, reported earlier in N. spumigena from New Zealand, have also been detected. Two of the total eight nodularin variants characterized in the present study, [dhb(5)]NOD and [MeAdda]NOD, have not been described earlier.
Collapse
Affiliation(s)
- Hanna Mazur-Marzec
- Department of Marine Biology and Ecology, University of Gdańsk, Al. Marszałka Piłsudskiego 46, 81-378 Gdynia, Poland.
| | | | | | | |
Collapse
|
33
|
|
34
|
Broda MA, Siodłak D, Rzeszotarska B. Conformational investigation of alpha,beta-dehydropeptides. N-acetyl-(E)-dehydrophenylalanine N'-methylamide: conformational properties from infrared and theoretical studies, part XIV. J Pept Sci 2005; 11:235-44. [PMID: 15635637 DOI: 10.1002/psc.601] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
N-Acetyl-(E)-dehydrophenylalanine N'-methylamide [Ac-(E)-DeltaPhe-NHMe], one of a few representative (E)-alpha,beta-dehydroamino acids, was studied by FTIR in dichloromethane and acetonitrile. To support spectroscopic interpretations and to gain some deeper insight into the Ac-(E)-DeltaPhe-NHMe molecule, the Ramachandran potential energy surface was calculated by the B3LYP/6-31G*//HF/3-21G method and the conformers localized were fully optimized at the B3LYP/6-31 + G** level. The spectra and calculations were compared with those of the related molecules Ac-DeltaAla-NHMe and Ac-(Z)-DeltaPhe-NHMe. The title compound assumes two conformational states in equilibrium in dichloromethane solution with a predominance of the extended conformer E. The Ac-(E)-DeltaPhe-NHMe spectrum is like that of Ac-DeltaAla-NHMe, particularly in the region of bands AI and AII, and unlike that of Ac-(Z)-DeltaPhe-NHMe. The positions of bands AI and II together with the nu(s)(N1--H1) band proves that the conformers E of both DeltaAla and (E)-DeltaPhe compounds are stabilized by the quite strong C5 hydrogen bonds N1--H1...O2. The same conclusion is drawn from the Ramachandran diagrams. The conformers E of both compounds are placed in the global minima and the gaps in energy order between them and the second conformer are large. The conformers E of DeltaAla and (E)-DeltaPhe, apart from the N1--H1...O2 hydrogen bond, show the Cbeta--H...O1 interaction, and Ac-(E)-DeltaPhe-NHMe displays the NH/pi interaction with the N2--H2 projecting in the first carbon atom of the phenyl ring. The C5 hydrogen bond is stronger in (E)-DeltaPhe than that in the DeltaAla compound. This is in agreement with interactions found in the calculated structures and can be explained by the influence of the phenyl ring in position (E). In acetonitrile, the molecule of Ac-(E)-DeltaPhe-NHMe loses its C5 hydrogen bond and becomes unfolded, whereas that of Ac-DeltaAla-NHMe does not vary practically. Adopting conformation E in a non-polar solvent seems to be a general feature of the (E)-DeltaXaa residues.
Collapse
|
35
|
Kurmayer R, Christiansen G, Gumpenberger M, Fastner J. Genetic identification of microcystin ecotypes in toxic cyanobacteria of the genus Planktothrix. MICROBIOLOGY-SGM 2005; 151:1525-1533. [PMID: 15870462 DOI: 10.1099/mic.0.27779-0] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Microcystins (MCs) are toxic heptapeptides which are synthesized by the filamentous cyanobacterium Planktothrix and other genera via non-ribosomal peptide synthesis. MCs share the common structure cyclo(-D-ala1-L-X2-D-erythro-beta-iso-aspartic acid3-L-Z4-adda5-D-Glu6-N-methyl-dehydroalanine7) [Adda; (2S, 3S, 8S, 9S)-3-amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4,6-dienoic acid], in which numerous MC variants have been reported. In general, the variation in structure is due to different amino acid residues in positions 7, 2 and 4 within the MC molecule, which are thought to be activated by the adenylation domains mcyAAd1, mcyBAd1 and mcyCAd, respectively. It was the aim of the study (i) to identify MC ecotypes that differed in the production of specific MC variants and (ii) to correlate the genetic variation within adenylation domains with the observed MC variants among 17 Planktothrix strains. Comparison of the sequences of mcyAAd1 revealed two distinctive Ad-genotypes differing in base pair composition and the insertion of an N-methyl transferase (NMT) domain. The mcyAAd1 genotype with NMT (2854 bp) correlated with N-methyl-dehydroalanine and the mcyAAd1 genotype without NMT (1692 bp) correlated with dehydrobutyrine in position 7. Within mcyBAd1, a lower genetic variation (0-4 %) and an exclusive correlation between one Ad-genotype and homotyrosine as well as another Ad-genotype and arginine in position 2 was found. The sequences of mcyCAd were found to be highly similar (0-1 % dissimilarity) and all strains contained arginine in position 4. The results on adenylation domain polymorphism do provide insights into the evolutionary origin of adenylation domains in Planktothrix and may be combined with ecological research in order to provide clues about the abundance of genetically defined MC ecotypes in nature.
Collapse
Affiliation(s)
- Rainer Kurmayer
- Austrian Academy of Sciences, Institute for Limnology, Mondseestraße 9, A-5310 Mondsee, Austria
| | - Guntram Christiansen
- University of Hawaii at Manoa, Department of Chemistry, 2545 McCarthy Hall, Honolulu, HI 96822, USA
| | - Marlies Gumpenberger
- Austrian Academy of Sciences, Institute for Limnology, Mondseestraße 9, A-5310 Mondsee, Austria
| | - Jutta Fastner
- Federal Environmental Agency, Corrensplatz 1, D-14195 Berlin, Germany
| |
Collapse
|
36
|
Liquid chromatography–tandem mass spectrometry and accurate m/z measurements of cyclic peptide cyanobacteria toxins. Trends Analyt Chem 2005. [DOI: 10.1016/j.trac.2005.04.013] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
37
|
Zurawell RW, Chen H, Burke JM, Prepas EE. Hepatotoxic cyanobacteria: a review of the biological importance of microcystins in freshwater environments. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2005; 8:1-37. [PMID: 15762553 DOI: 10.1080/10937400590889412] [Citation(s) in RCA: 303] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Cyanobacteria possess many adaptations to develop population maxima or "blooms" in lakes and reservoirs. A potential consequence of freshwater blooms of many cyanobacterial species is the production of potent toxins, including the cyclic hepatotoxins, microcystins (MCs). Approximately 70 MC variants have been isolated. Their toxicity to humans and other animals is well studied, because of public health concerns. This review focuses instead on the production and degradation of MCs in freshwater environments and their effects on aquatic organisms. Genetic research has revealed the existence of MC-related genes, yet the expression of these genes seems to be regulated by complex mechanisms and is influenced by environmental factors. In natural water bodies, the species composition of cyanobacterial communities and the ratio of toxic to nontoxic species and strains are largely responsible for total toxin production. Cyanobacteria play vital roles in aquatic food webs, yet production, accumulation, and toxicity patterns of MCs within aquatic food webs remain obscure.
Collapse
Affiliation(s)
- Ronald W Zurawell
- Department of Biological Sciences, Biological Sciences Building, University of Alberta, Edmonton, Alberta, Canada
| | | | | | | |
Collapse
|
38
|
Barco M, Flores C, Rivera J, Caixach J. Determination of microcystin variants and related peptides present in a water bloom of Planktothrix (Oscillatoria) rubescens in a Spanish drinking water reservoir by LC/ESI-MS. Toxicon 2004; 44:881-6. [PMID: 15530970 DOI: 10.1016/j.toxicon.2004.08.011] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2004] [Accepted: 08/19/2004] [Indexed: 11/29/2022]
Abstract
A water bloom of Planktothrix (Oscillatoria) rubescens was observed in a drinking water reservoir in central Spain in 2003. Microcystins where analysed by LC/ESI-MS in 21 samples collected from this reservoir in five different days between March and May. A demethylated variant of microcystin-RR was identified as the major microcystin in most samples. Trace levels of microcystin-LR, -RR and -YR were detected in some samples. Four less common microcystins, with [M+H]+ ions at m/z 960, 981, 1045 and 1053, were also found. Total extracellular microcystin concentration varied from 0.010 to 19.126 microg l(-1). Furthermore, anabaenopeptins B and F as well as Oscillamide Y were also identified in these samples.
Collapse
Affiliation(s)
- Mónica Barco
- Mass Spectrometry Laboratory, Department of Ecotechnologies, IIQAB-CSIC, C/Jordi Girona 18-26, 08034 Barcelona, Spain
| | | | | | | |
Collapse
|
39
|
Moffitt MC, Neilan BA. Characterization of the nodularin synthetase gene cluster and proposed theory of the evolution of cyanobacterial hepatotoxins. Appl Environ Microbiol 2004; 70:6353-62. [PMID: 15528492 PMCID: PMC525115 DOI: 10.1128/aem.70.11.6353-6362.2004] [Citation(s) in RCA: 158] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2004] [Accepted: 06/22/2004] [Indexed: 11/20/2022] Open
Abstract
Nodularia spumigena is a bloom-forming cyanobacterium which produces the hepatotoxin nodularin. The complete gene cluster encoding the enzymatic machinery required for the biosynthesis of nodularin in N. spumigena strain NSOR10 was sequenced and characterized. The 48-kb gene cluster consists of nine open reading frames (ORFs), ndaA to ndaI, which are transcribed from a bidirectional regulatory promoter region and encode nonribosomal peptide synthetase modules, polyketide synthase modules, and tailoring enzymes. The ORFs flanking the nda gene cluster in the genome of N. spumigena strain NSOR10 were identified, and one of them was found to encode a protein with homology to previously characterized transposases. Putative transposases are also associated with the structurally related microcystin synthetase (mcy) gene clusters derived from three cyanobacterial strains, indicating a possible mechanism for the distribution of these biosynthetic gene clusters between various cyanobacterial genera. We propose an alternative hypothesis for hepatotoxin evolution in cyanobacteria based on the results of comparative and phylogenetic analyses of the nda and mcy gene clusters. These analyses suggested that nodularin synthetase evolved from a microcystin synthetase progenitor. The identification of the nodularin biosynthetic gene cluster and evolution of hepatotoxicity in cyanobacteria reported in this study may be valuable for future studies on toxic cyanobacterial bloom formation. In addition, an appreciation of the natural evolution of nonribosomal biosynthetic pathways will be vital for future combinatorial engineering and rational design of novel metabolites and pharmaceuticals.
Collapse
Affiliation(s)
- Michelle C Moffitt
- School of Microbiology and Immunology, The University of New South Wales, Sydney, New South Wales, Australia
| | | |
Collapse
|
40
|
Sano T, Takagi H, Kaya K. A Dhb-microcystin from the filamentous cyanobacterium Planktothrix rubescens. PHYTOCHEMISTRY 2004; 65:2159-2162. [PMID: 15279989 DOI: 10.1016/j.phytochem.2004.03.034] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2003] [Revised: 03/18/2004] [Indexed: 05/24/2023]
Abstract
A Dhb-microcystin variant was isolated from the filamentous cyanobacterium Planktothrix rubescens. Its structure was elucidated as (E)-Dhb-microcystin-HilR ([D-Asp3, (E)-Dhb7]microcystin-HilR) on the basis of spectral data and amino acid analysis after acid hydrolysis.
Collapse
Affiliation(s)
- Tomoharu Sano
- National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan.
| | | | | |
Collapse
|
41
|
Dahlmann J, Budakowski WR, Luckas B. Liquid chromatography-electrospray ionisation-mass spectrometry based method for the simultaneous determination of algal and cyanobacterial toxins in phytoplankton from marine waters and lakes followed by tentative structural elucidation of microcystins. J Chromatogr A 2003; 994:45-57. [PMID: 12779218 DOI: 10.1016/s0021-9673(03)00485-0] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A liquid chromatography (LC)-based method with mass spectrometric (MS) detection was developed for simultaneous determination of various algal and cyanobacterial toxins extracted from phytoplankton occurring world-wide in marine waters and lakes. The method enables quantification of saxitoxin, anatoxin-A, domoic acid, nodularin, microcystins, okadaic acid and dinophysistoxin-1 with a single chromatographic run. In addition, the applied chromatographic conditions allow isolation and identification of substances suspected to be "new" microcystins (cyclic peptides) by fraction collection, hydrolysis, derivatisation of resulting free amino acids with the modified chiral Marfey's reagent N-alpha-(2,4-dinitro-5-fluorophenyl)-L-valinamide (L-FDVA) and enantioselective analysis of the amino acid derivatives by LC-ESI-MS.
Collapse
Affiliation(s)
- Jens Dahlmann
- Department of Food Chemistry, Faculty of Biology and Pharmacy, University of Jena, Dornburger Str. 25, 07743 Jena, Germany.
| | | | | |
Collapse
|
42
|
Blom JF, Bister B, Bischoff D, Nicholson G, Jung G, Süssmuth RD, Jüttner F. Oscillapeptin J, a new grazer toxin of the freshwater cyanobacterium Planktothrix rubescens. JOURNAL OF NATURAL PRODUCTS 2003; 66:431-434. [PMID: 12662108 DOI: 10.1021/np020397f] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Oscillapeptin J (1), a new and highly potent crustacean grazer toxin, was isolated from the axenic cyanobacterium Planktothrix rubescens, which frequently forms blooms in freshwater lakes. Chemical and spectroscopic analyses, including high resolving MS and two-dimensional NMR, were used to elucidate the compound's structure as a depsiheptapeptide of the oscillapeptin type. Strict application of a bioassay-guided isolation procedure proved this compound to be one of the major causative agents (besides [d-Asp(3),(E)-Dhb(7)]microcystin-RR) of the acute grazer toxicity of P. rubescens from Lake Zürich. The LC(50) value of oscillapeptin J as determined for the freshwater crustacean Thamnocephalus platyurus was 15.6 microM.
Collapse
Affiliation(s)
- Judith F Blom
- Limnological Station, Institute of Plant Biology, University of Zürich, Seestrasse 187, 8802 Kilchberg, Switzerland.
| | | | | | | | | | | | | |
Collapse
|
43
|
Laub J, Henriksen P, Brittain SM, Wang J, Carmichael WW, Rinehart KL, Moestrup O. [ADMAdda5]-microcystins in Planktothrix agardhii strain PH-123 (cyanobacteria)--importance for monitoring of microcystins in the environment. ENVIRONMENTAL TOXICOLOGY 2002; 17:351-357. [PMID: 12203956 DOI: 10.1002/tox.10042] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Two major and two minor microcystins (MCYST) were isolated from a hepatotoxic Danish strain of Planktothrix agardhii (Gomont) Anagnostidis et Komárek by reversed-phase high-performance liquid chromatography. The microcystins were characterized by UV spectroscopy, amino acid analysis, fast atom bombardment mass spectrometry (FABMS), and high-resolution FABMS. The major microcystins were further analysed by collisionally induced tandem electrospray ionization MS. The microcystins were found to be demethylated variants of MCYST-HtyR (homotyrosine-arginine) and MCYST-LR (leucine-arginine). The two major microcystins contained an acetyl-demethyl variant (ADMAdda) of 3-amino-9-acetoxy-2,6,8-trimethyl-10-phenyldeca-4,6-dienoic acid (Adda). This is the first report of [ADMAdda5]-microcystins in Planktothrix. The two [ADMAdda5]-microcystins inhibited protein phosphatase activity but showed low cross-reactivity with antibodies of an enzyme-linked immunosorbent assay (ELISA), emphasizing the potential underestimation of the toxicity of natural blooms dominated by Planktothrix when microcystin content is quantified using only an ELISA.
Collapse
Affiliation(s)
- Jesper Laub
- Department of Phycology, Botanical Institute, University of Copenhagen, Øster Farimagsgade 2D, DK-1353 Copenhagen K, Denmark
| | | | | | | | | | | | | |
Collapse
|
44
|
Blom JF, Robinson JA, Jüttner F. High grazer toxicity of [D-Asp(3),(E)-Dhb(7)]microcystin-RR of Planktothrix rubescens as compared to different microcystins. Toxicon 2001; 39:1923-32. [PMID: 11600156 DOI: 10.1016/s0041-0101(01)00178-7] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Planktothrix rubescens, the dominant cyanobacterium in Lake Zürich, is generally considered to be toxic to zooplankton. The major toxin was determined by NMR spectroscopy and chemical analysis to be [D-Asp(3),(E)-Dhb(7)]microcystin-RR. The compound was isolated in high purity, and its 24-h acute grazer toxicity was compared with microcystin-LR, microcystin-RR, microcystin-YR, and nodularin using a Thamnocephalus platyurus bioassay. Based on LC(50) values [D-Asp(3),(E)-Dhb(7)]microcystin-RR was the most toxic microcystin tested. Nodularin was slightly more toxic under the conditions of the assay. The large number of individuals available for the grazer bioassay allowed the determination of dose-response curves of the different microcystins. These curves showed marked differences in their steepness. Microcystin-RR, which had nearly the same LC(50) as microcystin-LR and microcystin-YR, exhibited a very flat dose-response curve. This flat curve indicates that, for some individuals, lower concentrations of this microcystin are much more toxic than are the other two microcystins. Mortality of 100% requires much higher concentrations of microcystin-RR, indicating the resistance of some animals to the toxin. The purified [D-Asp(3),(E)-Dhb(7)]microcystin-RR exhibited a higher molar absorption coefficient determined by quantitative amino acid analysis than the coefficients generally used for other microcystins. This observation has consequences for the risk assessment for microcystins and makes a structural determination of microcystins an absolute requirement. The presence of the dehydrobutyrine residue may be the reason for the higher specific toxicity of [D-Asp(3),(E)-Dhb(7)]microcystin-RR when compared to the N-methyldehydroalanine-containing microcystins.
Collapse
Affiliation(s)
- J F Blom
- Limnologische Station, Institut für Pflanzenbiologie, Universität Zürich, Seestr. 187, 8802 Kilchberg, Switzerland.
| | | | | |
Collapse
|
45
|
Kaya K, Sano T, Inoue H, Takagi H. Selective determination of total normal microcystin by colorimetry, LC/UV detection and/or LC/MS. Anal Chim Acta 2001. [DOI: 10.1016/s0003-2670(01)01391-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
46
|
Hummert C, Dahlmann J, Reinhardt K, Dang HPH, Dang DK, Luckas B. Liquid chromatography-mass spectrometry identification of microcystins inMicrocystis aeruginosa strain from lake Thanh Cong, Hanoi, Vietnam. Chromatographia 2001. [DOI: 10.1007/bf02492180] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
47
|
Sano T, Usui T, Ueda K, Osada H, Kaya K. Isolation of new protein phosphatase inhibitors from two cyanobacteria species, Planktothrix spp. JOURNAL OF NATURAL PRODUCTS 2001; 64:1052-1055. [PMID: 11520225 DOI: 10.1021/np0005356] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Two new protein phosphatase inhibitors, oscillamide B (1) and C (2), were isolated from the cyanobacteria Planktothrix (Oscillatoria) agardhii and P. rubescens. The structures of the inhibitors were elucidated by analysis of HRFABMS, 1D and 2D NMR spectra, and chemical degradation. These inhibitors are ureido-containing cyclic peptides and inhibited serine/threonine protein phosphatases PP1 and PP2A. The inhibitory activities were closely related to the Arg and N-Me-Hty residues in the peptides.
Collapse
Affiliation(s)
- T Sano
- National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-0053, Japan.
| | | | | | | | | |
Collapse
|
48
|
Park H, Namikoshi M, Brittain SM, Carmichael WW, Murphy T. [D-Leu(1)] microcystin-LR, a new microcystin isoplated from waterbloom in a Canadian prairie lake. Toxicon 2001; 39:855-62. [PMID: 11137546 DOI: 10.1016/s0041-0101(00)00224-5] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A previously undescribed cyclic heptapeptide hepatotoxin was isolated from a cyanobacteria waterbloom collected in Pakowki Lake, Alberta, Canada (49 degrees 20'N and 110 degrees 55'W). The compound was characterized by amino acid analysis, ESIMS/CID/MS, (1)H and (13)C NMR, and UV spectroscopy. Structure of the new microcystin was assigned as [D-Leu(1)]microcystin-LR (1). The amino acid composition is the same as microcystin-LR (2) except for D-Leu and L-Leu in 1 instead of D-Ala and L-Leu in 2. This is the first microcystin identified, among the 64 known microcystins, that has both a D- and L-Leu amino acid. Toxicity as measured by the protein phosphatase inhibition activity of 1 is similar to microcystin-LR. The presence of microcystins in waterblooms from this lake is discussed in relation to the almost yearly bird mortalities that have occurred there since 1995.
Collapse
Affiliation(s)
- H Park
- Department of Environmental Sciences, Faculty of Science, Shinshu University, Matsumoto 390-8621, Japan
| | | | | | | | | |
Collapse
|
49
|
Abstract
Microcystins are an increasingly important group of bioactive compounds produced by a number of mainly planktonic cyanobacteria. They are a family of cyclic heptapeptides that cause both acute and chronic toxicity. Purified microcystins are utilised in a range of research applications including toxicological and biochemical studies, development of detection systems and the investigation of water treatment strategies. The commercial availability of purified microcystins is still relatively limited and for many projects the cost of their purchase prohibitive. The purification of microcystins from both bloom material and laboratory cultures is reviewed including a discussion on extraction, separation, and the determination of purity and yield.
Collapse
Affiliation(s)
- L A Lawton
- School of Applied Sciences, Robert Gordon University, Aberdeen, UK.
| | | |
Collapse
|
50
|
Long BM, Jones GJ, Orr PT. Cellular microcystin content in N-limited Microcystis aeruginosa can be predicted from growth rate. Appl Environ Microbiol 2001; 67:278-83. [PMID: 11133456 PMCID: PMC92564 DOI: 10.1128/aem.67.1.278-283.2001] [Citation(s) in RCA: 154] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cell quotas of microcystin (Q(MCYST); femtomoles of MCYST per cell), protein, and chlorophyll a (Chl a), cell dry weight, and cell volume were measured over a range of growth rates in N-limited chemostat cultures of the toxic cyanobacterium Microcystis aeruginosa MASH 01-A19. There was a positive linear relationship between Q(MCYST) and specific growth rate (mu), from which we propose a generalized model that enables Q(MCYST) at any nutrient-limited growth rate to be predicted based on a single batch culture experiment. The model predicts Q(MCYST) from mu, mu(max) (maximum specific growth rate), Q(MCYSTmax) (maximum cell quota), and Q(MCYSTmin) (minimum cell quota). Under the conditions examined in this study, we predict a Q(MCYSTmax) of 0.129 fmol cell(-1) at mu(max) and a Q(MCYSTmin) of 0.050 fmol cell(-1) at mu = 0. Net MCYST production rate (R(MCYST)) asymptotes to zero at mu = 0 and reaches a maximum of 0.155 fmol cell(-1) day(-1) at mu(max). MCYST/dry weight ratio (milligrams per gram [dry weight]) increased linearly with mu, whereas the MCYST/protein ratio reached a maximum at intermediate mu. In contrast, the MCYST/Chl a ratio remained constant. Cell volume correlated negatively with mu, leading to an increase in intracellular MCYST concentration at high mu. Taken together, our results show that fast-growing cells of N-limited M. aeruginosa are smaller, are of lower mass, and have a higher intracellular MCYST quota and concentration than slow-growing cells. The data also highlight the importance of determining cell MCYST quotas, as potentially confusing interpretations can arise from determining MCYST content as a ratio to other cell components.
Collapse
Affiliation(s)
- B M Long
- Department of Botany, La Trobe University, Victoria 3086, Australia
| | | | | |
Collapse
|