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Pausch T, David T, Fleck-Kunde T, Pols H, Gurke J, Schmidt BM. Multifold Post-Modification of Macrocycles and Cages by Isocyanate-Induced Azadefluorination Cyclisation. Angew Chem Int Ed Engl 2024; 63:e202318362. [PMID: 38294139 DOI: 10.1002/anie.202318362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/22/2024] [Accepted: 01/22/2024] [Indexed: 02/01/2024]
Abstract
We present the multiple post-modification of organic macrocycles and cages, introducing functional groups into two- and three-dimensional supramolecular scaffolds bearing fluorine substituents, which opens up new possibilities in multi-step supramolecular chemistry employing the vast chemical space of readily available isocyanates. The mechanism and scope of the reaction that proceeds after isocyanate addition to the benzylamine motif via an azadefluorination cyclisation (ADFC) were investigated using DFT calculations, and a series of aromatic isocyanates with different electronic properties were tested. The compounds show excellent chemical stability and were fully characterised. They can be used for subsequent cross-coupling reactions, and ADFC can be used directly to generate cross-linked membranes from macrocycles or cages when using ditopic isocyanates. Single-crystal X-ray (SC-XRD) analysis shows the proof of the formation of the desired supramolecular entity together with the connectivity predicted by calculations and from 19F NMR shifts, allowing the late-stage functionalisation of self-assembled macrocycles and cages by ADFC.
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Affiliation(s)
- Tobias Pausch
- Institut für Organische Chemie und Makromolekulare Chemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Tim David
- Institut für Organische Chemie und Makromolekulare Chemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Tom Fleck-Kunde
- Institut für Organische Chemie und Makromolekulare Chemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Hendrik Pols
- Institut für Organische Chemie und Makromolekulare Chemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Johannes Gurke
- Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Straße 24-25, 14476, Potsdam, Germany
| | - Bernd M Schmidt
- Institut für Organische Chemie und Makromolekulare Chemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
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Lehnen AC, Gurke J, Bapolisi AM, Reifarth M, Bekir M, Hartlieb M. Xanthate-supported photo-iniferter (XPI)-RAFT polymerization: facile and rapid access to complex macromolecules. Chem Sci 2023; 14:593-603. [PMID: 36741515 PMCID: PMC9847670 DOI: 10.1039/d2sc05197d] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 11/28/2022] [Indexed: 11/30/2022] Open
Abstract
Xanthate-supported photo-iniferter (XPI)-reversible addition-fragmentation chain-transfer (RAFT) polymerization is introduced as a fast and versatile photo-polymerization strategy. Small amounts of xanthate are added to conventional RAFT polymerizations to act as a photo-iniferter under light irradiation. Radical exchange is facilitated by the main CTA ensuring control over the molecular weight distribution, while xanthate enables an efficient photo-(re)activation. The photo-active moiety is thus introduced into the polymer as an end group, which makes chain extension of the produced polymers possible directly by irradiation. This is in sharp contrast to conventional photo-initiators, or photo electron transfer (PET)-RAFT polymerizations, where radical generation depends on the added small molecules. In contrast to regular photo-iniferter-RAFT polymerization, photo-activation is decoupled from polymerization control, rendering XPI-RAFT an elegant tool for the fabrication of defined and complex macromolecules. The method is oxygen tolerant and robust and was used to perform screenings in a well-plate format, and it was even possible to produce multiblock copolymers in a coffee mug under open-to-air conditions. XPI-RAFT does not rely on highly specialized equipment and qualifies as a universal tool for the straightforward synthesis of complex macromolecules. The method is user-friendly and broadens the scope of what can be achieved with photo-polymerization techniques.
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Affiliation(s)
- Anne-Catherine Lehnen
- University of Potsdam, Institute of ChemistryKarl-Liebknecht-Straße 24-25D-14476PotsdamGermany,Fraunhofer Institute for Applied Polymer Research (IAP)Geiselbergstraße 69D-14476PotsdamGermany
| | - Johannes Gurke
- University of Potsdam, Institute of ChemistryKarl-Liebknecht-Straße 24-25D-14476PotsdamGermany,Fraunhofer Institute for Applied Polymer Research (IAP)Geiselbergstraße 69D-14476PotsdamGermany
| | - Alain M. Bapolisi
- University of Potsdam, Institute of ChemistryKarl-Liebknecht-Straße 24-25D-14476PotsdamGermany
| | - Martin Reifarth
- University of Potsdam, Institute of ChemistryKarl-Liebknecht-Straße 24-25D-14476PotsdamGermany,Fraunhofer Institute for Applied Polymer Research (IAP)Geiselbergstraße 69D-14476PotsdamGermany
| | - Marek Bekir
- University of Potsdam, Institute of Physics and AstronomyKarl-Liebknecht-Straße 24-25D-14476PotsdamGermany
| | - Matthias Hartlieb
- University of Potsdam, Institute of ChemistryKarl-Liebknecht-Straße 24-25D-14476PotsdamGermany,Fraunhofer Institute for Applied Polymer Research (IAP)Geiselbergstraße 69D-14476PotsdamGermany
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Gurke J, Naegele TE, Hilton S, Pezone R, Curto VF, Barone DG, List-Kratochvil EJW, Carnicer-Lombarte A, Malliaras GG. Hybrid fabrication of multimodal intracranial implants for electrophysiology and local drug delivery. Mater Horiz 2022; 9:1727-1734. [PMID: 35474130 PMCID: PMC9169700 DOI: 10.1039/d1mh01855h] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 04/21/2022] [Indexed: 05/31/2023]
Abstract
New fabrication approaches for mechanically flexible implants hold the key to advancing the applications of neuroengineering in fundamental neuroscience and clinic. By combining the high precision of thin film microfabrication with the versatility of additive manufacturing, we demonstrate a straight-forward approach for the prototyping of intracranial implants with electrode arrays and microfluidic channels. We show that the implant can modulate neuronal activity in the hippocampus through localized drug delivery, while simultaneously recording brain activity by its electrodes. Moreover, good implant stability and minimal tissue response are seen one-week post-implantation. Our work shows the potential of hybrid fabrication combining different manufacturing techniques in neurotechnology and paves the way for a new approach to the development of multimodal implants.
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Affiliation(s)
- Johannes Gurke
- University of Cambridge, Electrical Engineering Division, 9 JJ Thomson Ave, Cambridge, CB3 0FA, UK.
| | - Tobias E Naegele
- University of Cambridge, Electrical Engineering Division, 9 JJ Thomson Ave, Cambridge, CB3 0FA, UK.
| | - Sam Hilton
- University of Cambridge, Electrical Engineering Division, 9 JJ Thomson Ave, Cambridge, CB3 0FA, UK.
| | - Roberto Pezone
- University of Cambridge, Electrical Engineering Division, 9 JJ Thomson Ave, Cambridge, CB3 0FA, UK.
| | - Vincenzo F Curto
- University of Cambridge, Electrical Engineering Division, 9 JJ Thomson Ave, Cambridge, CB3 0FA, UK.
| | - Damiano G Barone
- University of Cambridge, Electrical Engineering Division, 9 JJ Thomson Ave, Cambridge, CB3 0FA, UK.
- University of Cambridge, School of Clinical Medicine, Department of Clinical Neurosciences, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK
| | - Emil J W List-Kratochvil
- Humboldt-Universität zu Berlin, Department of Chemistry and of Physics and IRIS Adlershof, Hybrid Devices Group, Zum Großen Windkanal 2, 12489 Berlin, Germany
- Helmholtz-Zentrum für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109, Berlin, Germany
| | | | - George G Malliaras
- University of Cambridge, Electrical Engineering Division, 9 JJ Thomson Ave, Cambridge, CB3 0FA, UK.
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Velasco‐Bosom S, Karam N, Carnicer‐Lombarte A, Gurke J, Casado N, Tomé LC, Mecerreyes D, Malliaras GG. Conducting Polymer-Ionic Liquid Electrode Arrays for High-Density Surface Electromyography. Adv Healthc Mater 2021; 10:e2100374. [PMID: 33991046 DOI: 10.1002/adhm.202100374] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 04/15/2021] [Indexed: 11/07/2022]
Abstract
Surface electromyography (EMG) is used as a medical diagnostic and to control prosthetic limbs. Electrode arrays that provide large-area, high density recordings have the potential to yield significant improvements in both fronts, but the need remains largely unfulfilled. Here, digital fabrication techniques are used to make scalable electrode arrays that capture EMG signals with mm spatial resolution. Using electrodes made of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) composites with the biocompatible ionic liquid (IL) cholinium lactate, the arrays enable high quality spatiotemporal recordings from the forearm of volunteers. These recordings allow to identify the motions of the index, little, and middle fingers, and to directly visualize the propagation of polarization/depolarization waves in the underlying muscles. This work paves the way for scalable fabrication of cutaneous electrophysiology arrays for personalized medicine and highly articulate prostheses.
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Affiliation(s)
| | - Nuzli Karam
- Electrical Engineering Division University of Cambridge Cambridge CB3 0FA UK
| | | | - Johannes Gurke
- Electrical Engineering Division University of Cambridge Cambridge CB3 0FA UK
| | - Nerea Casado
- POLYMAT University of the Basque Country UPV/EHU Avda. Tolosa 72, Donostia‐San Sebastián Gipuzkoa 20018 Spain
| | - Liliana C. Tomé
- POLYMAT University of the Basque Country UPV/EHU Avda. Tolosa 72, Donostia‐San Sebastián Gipuzkoa 20018 Spain
- LAQV/REQUIMTE, Chemistry Department NOVA School of Science and Technology Caparica 2829‐516 Portugal
| | - David Mecerreyes
- POLYMAT University of the Basque Country UPV/EHU Avda. Tolosa 72, Donostia‐San Sebastián Gipuzkoa 20018 Spain
- Ikerbasque Basque Foundation for Science Bilbao E‐48011 Spain
| | - George G. Malliaras
- Electrical Engineering Division University of Cambridge Cambridge CB3 0FA UK
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Middya S, Curto VF, Fernández‐Villegas A, Robbins M, Gurke J, Moonen EJM, Kaminski Schierle GS, Malliaras GG. Microelectrode Arrays for Simultaneous Electrophysiology and Advanced Optical Microscopy. Adv Sci (Weinh) 2021; 8:2004434. [PMID: 36246164 PMCID: PMC9539726 DOI: 10.1002/advs.202004434] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 03/01/2021] [Indexed: 05/09/2023]
Abstract
Advanced optical imaging techniques address important biological questions in neuroscience, where structures such as synapses are below the resolution limit of a conventional microscope. At the same time, microelectrode arrays (MEAs) are indispensable in understanding the language of neurons. Here, the authors show transparent MEAs capable of recording action potentials from neurons and compatible with advanced microscopy. The electrodes are made of the conducting polymer poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonate (PEDOT:PSS) and are patterned by optical lithography, ensuring scalable fabrication with good control over device parameters. A thickness of 380 nm ensures low enough impedance and >75% transparency throughout the visible part of the spectrum making them suitable for artefact-free recording in the presence of laser illumination. Using primary neuronal cells, the arrays record single units from multiple nearby sources with a signal-to-noise ratio of 7.7 (17.7 dB). Additionally, it is possible to perform calcium (Ca2+) imaging, a measure of neuronal activity, using the novel transparent electrodes. Different biomarkers are imaged through the electrodes using conventional and super-resolution microscopy (SRM), showing no qualitative differences compared to glass substrates. These transparent MEAs pave the way for harnessing the synergy between the superior temporal resolution of electrophysiology and the selectivity and high spatial resolution of optical imaging.
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Affiliation(s)
- Sagnik Middya
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgeCambridgeCB3 0ASUK
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FFUK
| | - Vincenzo F. Curto
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FFUK
| | - Ana Fernández‐Villegas
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgeCambridgeCB3 0ASUK
| | - Miranda Robbins
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgeCambridgeCB3 0ASUK
| | - Johannes Gurke
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FFUK
| | - Emma J. M. Moonen
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FFUK
- Department of Mechanical EngineeringMicrosystemsEindhoven University of TechnologyEindhoven5600 MBthe Netherlands
| | | | - George G. Malliaras
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FFUK
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Abstract
Photoswitchable acid-base pairs, whose pKa values can be reversibly altered, are attractive molecular tools to control chemical and biological processes with light. A significant, light-induced pKa change of three units in aqueous medium has been realized for two thermally stable states, which can be interconverted using UV and green light. The light-induced pKa modulation is based on incorporating a 3-H-thiazol-2-one moiety into the framework of a diarylethene photoswitch, which loses the heteroaromatic stabilization of the negatively charged conjugate base upon photochemical ring closure, and hence becomes significantly less acidic. In addition, the efficiency of the photoreactions is drastically increased in the deprotonated state, giving rise to catalytically enhanced photochromism. It appears that protonation has a significant influence on the shape of the ground- and excited-state potential energy surfaces, as indicated by quantum-chemical calculations.
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Affiliation(s)
- Johannes Gurke
- Department of Chemistry & IRIS Adlershof, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489, Berlin, Germany
| | - Šimon Budzák
- Laboratoire CEISAM, UMR CNRS 6230, Université de Nantes, 2 Rue de la Houssinière, BP 92208, 44322, Nantes Cedex 3, France.,Current address: Department of Chemistry, Faculty of Natural Sciences, Matej Bel University, Tajovského, 40, SK-97400, Banská Bystrica, Slovak Republic
| | - Bernd M Schmidt
- Department of Chemistry & IRIS Adlershof, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489, Berlin, Germany.,Current address: Institute of Organic and Macromolecular Chemistry, Heinrich-Heine-University Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Denis Jacquemin
- Laboratoire CEISAM, UMR CNRS 6230, Université de Nantes, 2 Rue de la Houssinière, BP 92208, 44322, Nantes Cedex 3, France
| | - Stefan Hecht
- Department of Chemistry & IRIS Adlershof, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489, Berlin, Germany
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Gurke J, Budzák Š, Schmidt BM, Jacquemin D, Hecht S. Effiziente lichtinduzierte p
K
a
‐Modulation, gekoppelt mit basenkatalysierter Photochromie. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201801270] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Johannes Gurke
- Institut für Chemie & IRIS Adlershof Humboldt-Universität zu Berlin Brook-Taylor-Straße 2 12489 Berlin Deutschland
| | - Šimon Budzák
- Laboratoire CEISAM UMR CNRS 6230 Université de Nantes 2 Rue de la Houssinière, BP 92208 44322 Nantes Cedex 3 Frankreich
- Institut für Chemie Naturwissenschaftliche Fakultät Matej Bel Universität Tajovského, 40 SK-97400 Banská Bystrica Slowakische Republik
| | - Bernd M. Schmidt
- Institut für Chemie & IRIS Adlershof Humboldt-Universität zu Berlin Brook-Taylor-Straße 2 12489 Berlin Deutschland
- Institut für Organische und Makromolekulare Chemie Heinrich-Heine-Universität Düsseldorf Universitätsstraße 1 40225 Düsseldorf Deutschland
| | - Denis Jacquemin
- Laboratoire CEISAM UMR CNRS 6230 Université de Nantes 2 Rue de la Houssinière, BP 92208 44322 Nantes Cedex 3 Frankreich
| | - Stefan Hecht
- Institut für Chemie & IRIS Adlershof Humboldt-Universität zu Berlin Brook-Taylor-Straße 2 12489 Berlin Deutschland
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Birkenfelder I, Gurke J, Grubert L, Hecht S, Schmidt BM. Click Chemistry Derived Pyridazines: Electron-Deficient Building Blocks with Defined Conformation and Packing Structure. Chem Asian J 2017; 12:3156-3161. [PMID: 29083098 DOI: 10.1002/asia.201701277] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 10/19/2017] [Indexed: 01/21/2023]
Abstract
A series of 3,6-bis(4-triazolyl)pyridazines equipped with terminal phenyl substituents with varying degree of fluorination were synthesized by using the facile copper-catalyzed azide-alkyne cycloaddition and their structures were thoroughly investigated in the gas phase, in solution, and in the solid state by employing DFT calculations, NMR spectroscopy, and single-crystal X-ray diffraction, respectively. On the molecular level, their structure is governed by the strong preference of the triazole-pyridazine linkages for the anti-conformation. The supramolecular organization of the molecules in the crystalline solid is controlled by π-stacking, C-H⋅⋅⋅π as well as C-F⋅⋅⋅H interactions. The latter can conveniently be tuned by the number and position of fluorine substituents in the terminal phenyl units, giving rise to either herringbone-like, 1D or 2D lamellar packing. Electrochemistry and optical spectroscopy of all compounds suggest that they might find use as electron-transporting/hole-blocking materials in organic electronics.
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Affiliation(s)
- Irén Birkenfelder
- Department of Chemistry and IRIS Adlershof, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489, Berlin, Germany
| | - Johannes Gurke
- Department of Chemistry and IRIS Adlershof, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489, Berlin, Germany
| | - Lutz Grubert
- Department of Chemistry and IRIS Adlershof, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489, Berlin, Germany
| | - Stefan Hecht
- Department of Chemistry and IRIS Adlershof, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489, Berlin, Germany
| | - Bernd M Schmidt
- Department of Chemistry and IRIS Adlershof, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489, Berlin, Germany
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Gurke J, Quick M, Ernsting NP, Hecht S. Acid-catalysed thermal cycloreversion of a diarylethene: a potential way for triggered release of stored light energy? Chem Commun (Camb) 2017; 53:2150-2153. [DOI: 10.1039/c6cc10182h] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The light energy stored in a closed diarylethene can efficiently be released upon addition of catalytic amounts of acid.
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Affiliation(s)
- J. Gurke
- Department of Chemistry
- Humboldt-Universität zu Berlin
- Berlin
- Germany
| | - M. Quick
- Department of Chemistry
- Humboldt-Universität zu Berlin
- Berlin
- Germany
| | - N. P. Ernsting
- Department of Chemistry
- Humboldt-Universität zu Berlin
- Berlin
- Germany
| | - S. Hecht
- Department of Chemistry
- Humboldt-Universität zu Berlin
- Berlin
- Germany
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Schmitz O, Gurke J, Bothe H. Molecular evidence for the aerobic expression of nifJ, encoding pyruvate:ferredoxin oxidoreductase, in cyanobacteria. FEMS Microbiol Lett 2001; 195:97-102. [PMID: 11167002 DOI: 10.1111/j.1574-6968.2001.tb10504.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Pyruvate:ferredoxin (flavodoxin) oxidoreductase (PFO, EC 1.2.7.1) catalyses the oxidative cleavage of pyruvate and coenzyme A to acetylcoenzyme A and CO2 with the simultaneous reduction of ferredoxin or flavodoxin. PFO occurs in anaerobes and in some aerobic archaea and bacteria. For cyanobacteria, activity measurements indicated the occurrence of PFO in heterocystous forms. The completely sequenced genomes of the unicellular Synechocystis sp. PCC 6803 and the heterocystous Anabaena sp. PCC 7120 and Nostoc punctiforme revealed the existence of one PFO (encoded by nifJ) in Synechocystis 6803 and N. punctiforme but two different PFOs, encoded by nifJ1 and nifJ2, in Anabaena. Sequence comparison now indicates that all cyanobacterial PFOs are more closely related to those of anaerobes than to those of aerobes. Reverse transcription-polymerase chain reaction (RT-PCR) experiments show that nifJ is transcribed in the presence of saturating iron concentrations in aerobically grown cells of the unicellular Synechococcus sp. PCC 6301 and Synechocystis 6803. Both nifJ genes are transcribed in aerobically grown Anabaena 7120. These findings are corroborated by luciferase reporter gene analysis of nifJ in Synechococcus sp. PCC 7942. The occurrence of PFO in these cyanobacteria is enigmatic.
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Affiliation(s)
- O Schmitz
- Botanical Institute, The University of Cologne, Gyrhofstr. 15, D-50923, Köln, Germany
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