1
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Bertran A, De Zotti M, Timmel CR, Di Valentin M, Bowen AM. Determining and controlling conformational information from orientationally selective light-induced triplet-triplet electron resonance spectroscopy for a set of bis-porphyrin rulers. Phys Chem Chem Phys 2024; 26:2589-2602. [PMID: 38170870 PMCID: PMC10793979 DOI: 10.1039/d3cp03454b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 10/31/2023] [Indexed: 01/05/2024]
Abstract
We recently reported a new technique, light-induced triplet-triplet electron resonance (LITTER) spectroscopy, which allows quantification of the dipolar interaction between the photogenerated triplet states of two chromophores. Here we carry out a systematic LITTER study, considering orientation selection by the detection pulses, of a series of bis-porphyrin model peptides with different porphyrin-porphyrin distances and relative orientations. Orientation-dependent analysis of the dipolar datasets yields conformational information of the molecules in frozen solution which is in good agreement with density functional theory predictions. Additionally, a fast partial orientational-averaging treatment produces distance distributions with minimized orientational artefacts. Finally, by direct comparison of LITTER data to double electron-electron resonance (DEER) measured on a system with Cu(II) coordinated into the porphyrins, we demonstrate the advantages of the LITTER technique over the standard DEER methodology. This is due to the remarkable spectroscopic properties of the photogenerated porphyrin triplet state. This work sets the basis for the use of LITTER in structural investigations of unmodified complex biological macromolecules, which could be combined with Förster resonance energy transfer and microscopy inside cells.
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Affiliation(s)
- Arnau Bertran
- Centre for Advanced Electron Spin Resonance and Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, UK.
| | - Marta De Zotti
- Department of Chemical Sciences, University of Padova, Via Marzolo 1, 35131 Padova, Italy
- Centro Interdipartimentale di Ricerca "Centro Studi di Economia e Tecnica dell'energia Giorgio Levi Cases", 35131 Padova, Italy.
| | - Christiane R Timmel
- Centre for Advanced Electron Spin Resonance and Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, UK.
| | - Marilena Di Valentin
- Department of Chemical Sciences, University of Padova, Via Marzolo 1, 35131 Padova, Italy
- Centro Interdipartimentale di Ricerca "Centro Studi di Economia e Tecnica dell'energia Giorgio Levi Cases", 35131 Padova, Italy.
| | - Alice M Bowen
- The National Research Facility for Electron Paramagnetic Resonance, Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
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2
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Bertran A, Morbiato L, Sawyer J, Dalla Torre C, Heyes DJ, Hay S, Timmel CR, Di Valentin M, De Zotti M, Bowen AM. Direct Comparison between Förster Resonance Energy Transfer and Light-Induced Triplet-Triplet Electron Resonance Spectroscopy. J Am Chem Soc 2023; 145:22859-22865. [PMID: 37839071 PMCID: PMC10603778 DOI: 10.1021/jacs.3c04685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Indexed: 10/17/2023]
Abstract
To carry out reliable and comprehensive structural investigations, the exploitation of different complementary techniques is required. Here, we report that dual triplet-spin/fluorescent labels enable the first parallel distance measurements by electron spin resonance (ESR) and Förster resonance energy transfer (FRET) on exactly the same molecules with orthogonal chromophores, allowing for direct comparison. An improved light-induced triplet-triplet electron resonance method with 2-color excitation is used, improving the signal-to-noise ratio of the data and yielding a distance distribution that provides greater insight than the single distance resulting from FRET.
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Affiliation(s)
- Arnau Bertran
- Centre
for Advanced Electron Spin Resonance and Inorganic Chemistry Laboratory,
Department of Chemistry, University of Oxford, Oxford OX1 3QR, United Kingdom
| | - Laura Morbiato
- Department
of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | - Jack Sawyer
- The
National Research Facility for Electron Paramagnetic Resonance, Department
of Chemistry, Manchester Institute of Biotechnology and Photon Science
Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Chiara Dalla Torre
- Department
of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | - Derren J. Heyes
- The
National Research Facility for Electron Paramagnetic Resonance, Department
of Chemistry, Manchester Institute of Biotechnology and Photon Science
Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Sam Hay
- The
National Research Facility for Electron Paramagnetic Resonance, Department
of Chemistry, Manchester Institute of Biotechnology and Photon Science
Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Christiane R. Timmel
- Centre
for Advanced Electron Spin Resonance and Inorganic Chemistry Laboratory,
Department of Chemistry, University of Oxford, Oxford OX1 3QR, United Kingdom
| | - Marilena Di Valentin
- Department
of Chemical Sciences, University of Padova, 35131 Padova, Italy
- Centro
Interdipartimentale di Ricerca “Centro Studi di Economia e
Tecnica dell’energia Giorgio Levi Cases”, 35131 Padova, Italy
| | - Marta De Zotti
- Department
of Chemical Sciences, University of Padova, 35131 Padova, Italy
- Centro
Interdipartimentale di Ricerca “Centro Studi di Economia e
Tecnica dell’energia Giorgio Levi Cases”, 35131 Padova, Italy
| | - Alice M. Bowen
- The
National Research Facility for Electron Paramagnetic Resonance, Department
of Chemistry, Manchester Institute of Biotechnology and Photon Science
Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
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3
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Sannikova NE, Kolokolov MI, Khlynova TA, Chubarov AS, Polienko YF, Fedin MV, Krumkacheva OA. Revealing light-induced structural shifts in G-quadruplex-porphyrin complexes: a pulsed dipolar EPR study. Phys Chem Chem Phys 2023; 25:22455-22466. [PMID: 37581249 DOI: 10.1039/d3cp01775c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/16/2023]
Abstract
The binding of G-quadruplex structures (G4s) with photosensitizers is of considerable importance in medicinal chemistry and drug discovery due to their promising potential in photodynamic therapy applications. G4s can experience structural changes as a result of ligand interactions and light exposure. Understanding these modifications is essential to uncover the fundamental biological roles of the complexes and optimize their therapeutic potential. The structural diversity of G4s makes it challenging to study their complexes with ligands, necessitating the use of various complementary methods to fully understand these interactions. In this study, we introduce, for the first time, the application of laser-induced dipolar EPR as a method to characterize G-quadruplex DNA complexes containing photosensitizers and to investigate light-induced structural modifications in these systems. To demonstrate the feasibility of this approach, we studied complexes of the human telomeric G-quadruplex (HTel-22) with cationic 5,10,15,20-tetrakis(1-methyl-4-pyridinio) porphyrin tetra(p-toluenesulfonate) (TMPyP4). In addition to showcasing a new methodology, we also aimed to provide insights into the mechanisms underlying photoinduced HTel-22/TMPyP4 structural changes, thereby aiding in the advancement of approaches targeting G4s in photodynamic therapy. EPR revealed G-quadruplex unfolding and dimer formation upon light exposure. Our findings demonstrate the potential of EPR spectroscopy for examining G4 complexes with photosensitizers and contribute to a better understanding of G4s' interactions with ligands under light.
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Affiliation(s)
- Natalya E Sannikova
- International Tomography Center SB RAS, 630090 Novosibirsk, Russia.
- Novosibirsk State University, Pirogova Str. 2, Novosibirsk 630090, Russia
| | - Mikhail I Kolokolov
- International Tomography Center SB RAS, 630090 Novosibirsk, Russia.
- Novosibirsk State University, Pirogova Str. 2, Novosibirsk 630090, Russia
| | - Tamara A Khlynova
- International Tomography Center SB RAS, 630090 Novosibirsk, Russia.
- Novosibirsk State University, Pirogova Str. 2, Novosibirsk 630090, Russia
| | - Alexey S Chubarov
- Institute of Chemical Biology and Fundamental Medicine SB RAS, Novosibirsk 630090, Russia
- Novosibirsk State University, Pirogova Str. 2, Novosibirsk 630090, Russia
| | - Yuliya F Polienko
- N.N. Vorozhtsov Institute of Organic Chemistry SB RAS, 630090 Novosibirsk, Russia
| | - Matvey V Fedin
- International Tomography Center SB RAS, 630090 Novosibirsk, Russia.
- Novosibirsk State University, Pirogova Str. 2, Novosibirsk 630090, Russia
| | - Olesya A Krumkacheva
- International Tomography Center SB RAS, 630090 Novosibirsk, Russia.
- Novosibirsk State University, Pirogova Str. 2, Novosibirsk 630090, Russia
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4
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Scherer A, Yildirim B, Drescher M. The effect of the zero-field splitting in light-induced pulsed dipolar electron paramagnetic resonance (EPR) spectroscopy. MAGNETIC RESONANCE (GOTTINGEN, GERMANY) 2023; 4:27-46. [PMID: 37904801 PMCID: PMC10583298 DOI: 10.5194/mr-4-27-2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 01/13/2023] [Indexed: 11/01/2023]
Abstract
Laser-induced magnetic dipole (LaserIMD) spectroscopy and light-induced double electron-electron resonance (LiDEER) spectroscopy are important techniques in the emerging field of light-induced pulsed dipolar electron paramagnetic resonance (EPR) spectroscopy (light-induced PDS). These techniques use the photoexcitation of a chromophore to the triplet state and measure its dipolar coupling to a neighboring electron spin, which allows the determination of distance restraints. To date, LaserIMD and LiDEER have been analyzed with software tools that were developed for a pair of two S = 1 / 2 spins and that neglected the zero-field splitting (ZFS) of the excited triplet. Here, we explore the limits of this assumption and show that the ZFS can have a significant effect on the shape of the dipolar trace. For a detailed understanding of the effect of the ZFS, a theoretical description for LaserIMD and LiDEER is derived, taking into account the non-secular terms of the ZFS. Simulations based on this model show that the effect of the ZFS is not that pronounced in LiDEER for experimentally relevant conditions. However, the ZFS leads to an additional decay in the dipolar trace in LaserIMD. This decay is not that pronounced in Q-band but can be quite noticeable for lower magnetic field strengths in X-band. Experimentally recorded LiDEER and LaserIMD data confirm these findings. It is shown that ignoring the ZFS in the data analysis of LaserIMD traces can lead to errors in the obtained modulation depths and background decays. In X-band, it is additionally possible that the obtained distance distribution is plagued by long distance artifacts.
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Affiliation(s)
- Andreas Scherer
- Department of Chemistry, Konstanz Research School Chemical Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Berk Yildirim
- Department of Chemistry, Konstanz Research School Chemical Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Malte Drescher
- Department of Chemistry, Konstanz Research School Chemical Biology, University of Konstanz, 78457 Konstanz, Germany
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5
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Scherer A, Yao X, Qi M, Wiedmaier M, Godt A, Drescher M. Increasing the Modulation Depth of Gd III-Based Pulsed Dipolar EPR Spectroscopy (PDS) with Porphyrin-Gd III Laser-Induced Magnetic Dipole Spectroscopy. J Phys Chem Lett 2022; 13:10958-10964. [PMID: 36399541 PMCID: PMC9720741 DOI: 10.1021/acs.jpclett.2c02138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 10/03/2022] [Indexed: 06/16/2023]
Abstract
Distance determination with pulsed EPR has become an important technique for the structural investigation of biomacromolecules, with double electron-electron resonance spectroscopy (DEER) as the most important method. GdIII-based spin labels are one of the most frequently used spin labels for DEER owing to their stability against reduction, high magnetic moment, and absence of orientation selection. A disadvantage of GdIII-GdIII DEER is the low modulation depth due to the broad EPR spectrum of GdIII. Here, we introduce laser-induced magnetic dipole spectroscopy (LaserIMD) with a spin pair consisting of GdIII(PymiMTA) and a photoexcited porphyrin as an alternative technique. We show that the excited state of the porphyrin is not disturbed by the presence of the GdIII complex and that herewith modulation depths of almost 40% are possible. This is significantly higher than the value of 7.2% that was achieved with GdIII-GdIII DEER.
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Affiliation(s)
- Andreas Scherer
- Department
of Chemistry and Konstanz Research School Chemical Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Xuemei Yao
- Faculty
of Chemistry and Center of Molecular Materials (CM2), Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Mian Qi
- Faculty
of Chemistry and Center of Molecular Materials (CM2), Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Max Wiedmaier
- Department
of Chemistry and Konstanz Research School Chemical Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Adelheid Godt
- Faculty
of Chemistry and Center of Molecular Materials (CM2), Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Malte Drescher
- Department
of Chemistry and Konstanz Research School Chemical Biology, University of Konstanz, 78457 Konstanz, Germany
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6
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Bertran A, Morbiato L, Aquilia S, Gabbatore L, De Zotti M, Timmel CR, Di Valentin M, Bowen AM. Erythrosin B as a New Photoswitchable Spin Label for Light-Induced Pulsed EPR Dipolar Spectroscopy. Molecules 2022; 27:molecules27217526. [PMID: 36364348 PMCID: PMC9657417 DOI: 10.3390/molecules27217526] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/27/2022] [Accepted: 10/29/2022] [Indexed: 11/06/2022] Open
Abstract
We present a new photoswitchable spin label for light-induced pulsed electron paramagnetic resonance dipolar spectroscopy (LiPDS), the photoexcited triplet state of erythrosin B (EB), which is ideal for biological applications. With this label, we perform an in-depth study of the orientational effects in dipolar traces acquired using the refocused laser-induced magnetic dipole technique to obtain information on the distance and relative orientation between the EB and nitroxide labels in a rigid model peptide, in good agreement with density functional theory predictions. Additionally, we show that these orientational effects can be averaged to enable an orientation-independent analysis to determine the distance distribution. Furthermore, we demonstrate the feasibility of these experiments above liquid nitrogen temperatures, removing the need for expensive liquid helium or cryogen-free cryostats. The variety of choices in photoswitchable spin labels and the affordability of the experiments are critical for LiPDS to become a widespread methodology in structural biology.
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Affiliation(s)
- Arnau Bertran
- Centre for Advanced Electron Spin Resonance and Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QR, UK
| | - Laura Morbiato
- Department of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | - Sara Aquilia
- Department of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | - Laura Gabbatore
- Department of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | - Marta De Zotti
- Department of Chemical Sciences, University of Padova, 35131 Padova, Italy
- Centro Interdipartimentale di Ricerca “Centro Studi di Economia e Tecnica dell’Energia Giorgio Levi Cases”, University of Padova, 35131 Padova, Italy
| | - Christiane R. Timmel
- Centre for Advanced Electron Spin Resonance and Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QR, UK
| | - Marilena Di Valentin
- Department of Chemical Sciences, University of Padova, 35131 Padova, Italy
- Centro Interdipartimentale di Ricerca “Centro Studi di Economia e Tecnica dell’Energia Giorgio Levi Cases”, University of Padova, 35131 Padova, Italy
- Correspondence: (M.D.V.); (A.M.B.)
| | - Alice M. Bowen
- The National Research Facility for Electron Paramagnetic Resonance, Department of Chemistry and Photon Science Institute, The University of Manchester, Manchester M13 9PL, UK
- Correspondence: (M.D.V.); (A.M.B.)
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7
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Cantelli A, Malferrari M, Mattioli EJ, Marconi A, Mirra G, Soldà A, Marforio TD, Zerbetto F, Rapino S, Di Giosia M, Calvaresi M. Enhanced Uptake and Phototoxicity of C 60@albumin Hybrids by Folate Bioconjugation. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:nano12193501. [PMID: 36234629 PMCID: PMC9565331 DOI: 10.3390/nano12193501] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 09/23/2022] [Accepted: 09/28/2022] [Indexed: 06/12/2023]
Abstract
Fullerenes are considered excellent photosensitizers, being highly suitable for photodynamic therapy (PDT). A lack of water solubility and low biocompatibility are, in many instances, still hampering the full exploitation of their potential in nanomedicine. Here, we used human serum albumin (HSA) to disperse fullerenes by binding up to five fullerene cages inside the hydrophobic cavities. Albumin was bioconjugated with folic acid to specifically address the folate receptors that are usually overexpressed in several solid tumors. Concurrently, tetramethylrhodamine isothiocyanate, TRITC, a tag for imaging, was conjugated to C60@HSA in order to build an effective phototheranostic platform. The in vitro experiments demonstrated that: (i) HSA disperses C60 molecules in a physiological environment, (ii) HSA, upon C60 binding, maintains its biological identity and biocompatibility, (iii) the C60@HSA complex shows a significant visible-light-induced production of reactive oxygen species, and (iv) folate bioconjugation improves both the internalization and the PDT-induced phototoxicity of the C60@HSA complex in HeLa cells.
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8
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Bertran A, Barbon A, Bowen AM, Di Valentin M. Light-induced pulsed dipolar EPR spectroscopy for distance and orientation analysis. Methods Enzymol 2022; 666:171-231. [PMID: 35465920 DOI: 10.1016/bs.mie.2022.02.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Measuring distances in biology at the molecular level is of great importance for understanding the structure and function of proteins, nucleic acids and other biological molecules and their complexes. Pulsed Dipolar Spectroscopy (PDS) offers advantages with respect to other methods as it is uniquely sensitive and specific to electronic spin centers and allows measurements in near-native conditions, comprising the in-cell environment. PDS methods measure the electron spin-spin dipolar interaction, therefore they require the presence of at least two paramagnetic centers, which are often stable radicals. Recent developments have introduced transient triplet states, photo-activated by a laser pulse, as spin labels and probes, thereby establishing a new family of techniques-Light-induced PDS (LiPDS). In this chapter, an overview of these methods is provided, looking at the chromophores that can be used for LiPDS and some of the technical aspects of the experiments. A guide to the choice of technique that can yield the best results, depending on the type of system studied and the information required, is provided. Examples of previous LiPDS studies of model systems and proteins are given. Characterization data for the chromophores used in these studies is tabulated to help selection of appropriate triplet state probes in future studies.
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Affiliation(s)
- Arnau Bertran
- Centre for Advanced Electron Spin Resonance and Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom
| | - Antonio Barbon
- Department of Chemical Sciences, University of Padova, Padova, Italy
| | - Alice M Bowen
- Centre for Advanced Electron Spin Resonance and Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom; EPSRC National Research Facility for Electron Paramagnetic Resonance Spectroscopy, Department of Chemistry and Photon Science Institute, The University of Manchester, Manchester, United Kingdom.
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9
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Bowen AM, Bertran A, Henbest KB, Gobbo M, Timmel CR, Di Valentin M. Orientation-Selective and Frequency-Correlated Light-Induced Pulsed Dipolar Spectroscopy. J Phys Chem Lett 2021; 12:3819-3826. [PMID: 33856805 PMCID: PMC8154851 DOI: 10.1021/acs.jpclett.1c00595] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 03/31/2021] [Indexed: 06/12/2023]
Abstract
We explore the potential of orientation-resolved pulsed dipolar spectroscopy (PDS) in light-induced versions of the experiment. The use of triplets as spin-active moieties for PDS offers an attractive tool for studying biochemical systems containing optically active cofactors. Cofactors are often rigidly bound within the protein structure, providing an accurate positional marker. The rigidity leads to orientation selection effects in PDS, which can be analyzed to give both distance and mutual orientation information. Herein we present a comprehensive analysis of the orientation selection of a full set of light-induced PDS experiments. We exploit the complementary information provided by the different light-induced techniques to yield atomic-level structural information. For the first time, we measure a 2D frequency-correlated laser-induced magnetic dipolar spectrum, and we are able to monitor the complete orientation dependence of the system in a single experiment. Alternatively, the summed spectrum enables an orientation-independent analysis to determine the distance distribution.
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Affiliation(s)
- Alice M. Bowen
- Department
of Chemistry, Photon Science Institute and The National EPR Research
Facility, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
- Centre
for Advanced Electron Spin Resonance and Inorganic Chemistry Laboratory,
Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Arnau Bertran
- Centre
for Advanced Electron Spin Resonance and Inorganic Chemistry Laboratory,
Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Kevin B. Henbest
- Centre
for Advanced Electron Spin Resonance and Inorganic Chemistry Laboratory,
Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Marina Gobbo
- Department
of Chemical Sciences, University of Padova, Via Marzolo 1, 35131 Padova, Italy
| | - Christiane R. Timmel
- Centre
for Advanced Electron Spin Resonance and Inorganic Chemistry Laboratory,
Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Marilena Di Valentin
- Department
of Chemical Sciences, University of Padova, Via Marzolo 1, 35131 Padova, Italy
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10
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Bertran A, Henbest KB, De Zotti M, Gobbo M, Timmel CR, Di Valentin M, Bowen AM. Light-Induced Triplet-Triplet Electron Resonance Spectroscopy. J Phys Chem Lett 2021; 12:80-85. [PMID: 33306382 PMCID: PMC8016185 DOI: 10.1021/acs.jpclett.0c02884] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 11/19/2020] [Indexed: 06/12/2023]
Abstract
We present a new technique, light-induced triplet-triplet electron resonance spectroscopy (LITTER), which measures the dipolar interaction between two photoexcited triplet states, enabling both the distance and angular distributions between the two triplet moieties to be determined on a nanometer scale. This is demonstrated for a model bis-porphyrin peptide that renders dipolar traces with strong orientation selection effects. Using simulations and density functional theory calculations, we extract distance distributions and relative orientations of the porphyrin moieties, allowing the dominant conformation of the peptide in a frozen solution to be identified. LITTER removes the requirement of current light-induced electron spin resonance pulse dipolar spectroscopy techniques to have a permanent paramagnetic moiety, becoming more suitable for in-cell applications and facilitating access to distance determination in unmodified macromolecular systems containing photoexcitable moieties. LITTER also has the potential to enable direct comparison with Förster resonance energy transfer and combination with microscopy inside cells.
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Affiliation(s)
- Arnau Bertran
- Centre
for Advanced Electron Spin Resonance and Inorganic Chemistry Laboratory,
Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Kevin B. Henbest
- Centre
for Advanced Electron Spin Resonance and Inorganic Chemistry Laboratory,
Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Marta De Zotti
- Department
of Chemical Sciences, University of Padova, Via Marzolo 1, 35131 Padova, Italy
| | - Marina Gobbo
- Department
of Chemical Sciences, University of Padova, Via Marzolo 1, 35131 Padova, Italy
| | - Christiane R. Timmel
- Centre
for Advanced Electron Spin Resonance and Inorganic Chemistry Laboratory,
Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Marilena Di Valentin
- Department
of Chemical Sciences, University of Padova, Via Marzolo 1, 35131 Padova, Italy
| | - Alice M. Bowen
- Centre
for Advanced Electron Spin Resonance and Inorganic Chemistry Laboratory,
Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
- Department
of Chemistry and Photon Science Institute, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
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11
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Williams L, Tischlik S, Scherer A, Fischer JWA, Drescher M. Site-directed attachment of photoexcitable spin labels for light-induced pulsed dipolar spectroscopy. Chem Commun (Camb) 2020; 56:14669-14672. [PMID: 33159780 DOI: 10.1039/d0cc03101a] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Photoexcited triplet states are gaining popularity as spin labels in pulsed electron paramagnetic resonance (EPR) spectroscopy. Here, we demonstrate that the fluorophores Eosin Y, Rose Bengal and Atto Thio12 are suitable markers for distance determination by laser-induced magnetic dipole (LaserIMD) spectroscopy in proteins that lack an intrinsic photoexcitable center.
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Affiliation(s)
- Lara Williams
- Department of Chemistry and Konstanz Research School Chemical Biology (KoRS-CB), University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany.
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12
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Serda M, Szewczyk G, Krzysztyńska-Kuleta O, Korzuch J, Dulski M, Musioł R, Sarna T. Developing [60]Fullerene Nanomaterials for Better Photodynamic Treatment of Non-Melanoma Skin Cancers. ACS Biomater Sci Eng 2020; 6:5930-5940. [PMID: 33320587 DOI: 10.1021/acsbiomaterials.0c00932] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Skin cancer is the most common cancer in the U.S.A. and Europe. Its subtype, squamous skin carcinoma (SCC), if allowed to grow, has the potential to metastasize and can become deadly. Currently, carbon nanomaterials are being developed to treat cancer due to their attractive physicochemical and biological properties such as an enhanced permeability effect and their ability to produce reactive oxygen species. Here, we describe the synthesis of two water-soluble aminofullerenes (MonoaminoC60 and HexakisaminoC60), which were evaluated as novel [60]fullerene based photosentizers exhibiting anticancer properties. Moreover, the previously described neutral glycofullerene GF1 and its peracetylated lipophilic precursor MMS48 were compared with the aminofullerenes for their ability to generate reactive oxygen species and oxidize lipids. Remarkably, the generation of singlet oxygen and a superoxide radical by HexakisaminoC60 was found to be markedly elevated in the presence of bovine serum albumin and NADH, respectively. Mechanistic studies of lipid peroxidation using cholesterol as a unique reporter molecule revealed that although all four fullerene nanomaterials primarily generated singlet oxygen, superoxide anion was also formed, which suggest a mixed mechanism of action (in which Type I and Type II photochemistry is involved). The [60]fullerene derivative HexakisaminoC60 was also studied for its phototoxicity in squamous skin cancer cell line (A431) using the MTT test and propidium iodide staining.
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Affiliation(s)
- Maciej Serda
- Institute of Chemistry, University of Silesia in Katowice, Katowice 40-007, Poland
| | - Grzegorz Szewczyk
- Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Kraków 30-387, Poland
| | - Olga Krzysztyńska-Kuleta
- Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Kraków 30-387, Poland
| | - Julia Korzuch
- Institute of Chemistry, University of Silesia in Katowice, Katowice 40-007, Poland
| | - Mateusz Dulski
- Institute of Materials Engineering, University of Silesia in Katowice, 75 Pulku Piechoty 1A, Chorzów 41-500, Poland.,Silesian Center for Education and Interdisciplinary Research, University of Silesia in Katowice, 75 Pulku Piechoty 1A, 41-500 Chorzów, Poland
| | - Robert Musioł
- Institute of Chemistry, University of Silesia in Katowice, Katowice 40-007, Poland
| | - Tadeusz Sarna
- Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Kraków 30-387, Poland
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13
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Avalos CE, Richert S, Socie E, Karthikeyan G, Casano G, Stevanato G, Kubicki DJ, Moser JE, Timmel CR, Lelli M, Rossini AJ, Ouari O, Emsley L. Enhanced Intersystem Crossing and Transient Electron Spin Polarization in a Photoexcited Pentacene–Trityl Radical. J Phys Chem A 2020; 124:6068-6075. [DOI: 10.1021/acs.jpca.0c03498] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Claudia E. Avalos
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Sabine Richert
- Centre for Advanced Electron Spin Resonance (CAESR), University of Oxford, South Parks Road, OX1 3QR Oxford, United Kingdom
| | - Etienne Socie
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | | | | | - Gabriele Stevanato
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Dominik J. Kubicki
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Jacques E. Moser
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Christiane R. Timmel
- Centre for Advanced Electron Spin Resonance (CAESR), University of Oxford, South Parks Road, OX1 3QR Oxford, United Kingdom
| | - Moreno Lelli
- Center of Magnetic Resonance (CERM), University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Italy
- Department of Chemistry “Ugo Schiff”, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy
| | - Aaron J. Rossini
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | | | - Lyndon Emsley
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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14
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Dal Farra MG, Martin C, Bergantino E, Kandrashkin YE, van der Est A, Di Valentin M. Electron spin polarization transfer induced by triplet–radical interactions in the weakly coupled regime. Phys Chem Chem Phys 2020; 22:19982-19991. [DOI: 10.1039/d0cp03565c] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
We report the observation of electron spin polarization transfer from the triplet state of a porphyrin to a weakly coupled nitroxide radical in a mutant of human neuroglobin (NGB).
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Affiliation(s)
| | - Caterina Martin
- Dipartimento di Biologia
- Università degli Studi di Padova
- I-35131 Padova
- Italy
| | | | - Yuri E. Kandrashkin
- Zavoisky Physical-Technical Institute
- FRC Kazan Scientific Center of RAS
- Kazan 420029
- Russian Federation
| | | | - Marilena Di Valentin
- Dipartimento di Scienze Chimiche
- Università degli studi di Padova
- 35131 Padova
- Italy
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