1
|
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.
Collapse
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.
| |
Collapse
|
2
|
Denysenkov V, Prisner TF, Neugebauer P, Stoll S, Marko A. Macroscopic sample shape effect on pulse electron double resonance (PELDOR) signal. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2023; 356:107564. [PMID: 37852111 DOI: 10.1016/j.jmr.2023.107564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 10/05/2023] [Accepted: 10/06/2023] [Indexed: 10/20/2023]
Abstract
Pulse electron double resonance (PELDOR), also called double electron-electron resonance (DEER), is a technique capable of measuring the strength of electron spin dipolar interactions, revealing spin-spin distance distributions in ordered and disordered solid materials. Previous work has shown that PELDOR signals acquire an out-of-phase component under conditions of high electron spin polarization, such as at low temperatures and high fields. In this paper, we show theoretically and experimentally that the size and sign of this effect depends on the macroscopic shape of the sample and its orientation in the external magnetic field. This effect is caused by dipolar interactions between distant spins and provides new insights into the fundamental physics of PELDOR.
Collapse
Affiliation(s)
- Vasyl Denysenkov
- Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance, Goethe University Frankfurt, Max-von-Laue Str. 7, 60437, Frankfurt am Main, Germany
| | - Thomas F Prisner
- Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance, Goethe University Frankfurt, Max-von-Laue Str. 7, 60437, Frankfurt am Main, Germany
| | - Petr Neugebauer
- Central European Institute of Technology and Brno University of Technology, Purkynova 123, Brno, 61200, Czech Republic
| | - Stefan Stoll
- Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195-1700, USA
| | - Andriy Marko
- Central European Institute of Technology and Brno University of Technology, Purkynova 123, Brno, 61200, Czech Republic.
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
Eills J, Budker D, Cavagnero S, Chekmenev EY, Elliott SJ, Jannin S, Lesage A, Matysik J, Meersmann T, Prisner T, Reimer JA, Yang H, Koptyug IV. Spin Hyperpolarization in Modern Magnetic Resonance. Chem Rev 2023; 123:1417-1551. [PMID: 36701528 PMCID: PMC9951229 DOI: 10.1021/acs.chemrev.2c00534] [Citation(s) in RCA: 64] [Impact Index Per Article: 64.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Magnetic resonance techniques are successfully utilized in a broad range of scientific disciplines and in various practical applications, with medical magnetic resonance imaging being the most widely known example. Currently, both fundamental and applied magnetic resonance are enjoying a major boost owing to the rapidly developing field of spin hyperpolarization. Hyperpolarization techniques are able to enhance signal intensities in magnetic resonance by several orders of magnitude, and thus to largely overcome its major disadvantage of relatively low sensitivity. This provides new impetus for existing applications of magnetic resonance and opens the gates to exciting new possibilities. In this review, we provide a unified picture of the many methods and techniques that fall under the umbrella term "hyperpolarization" but are currently seldom perceived as integral parts of the same field. Specifically, before delving into the individual techniques, we provide a detailed analysis of the underlying principles of spin hyperpolarization. We attempt to uncover and classify the origins of hyperpolarization, to establish its sources and the specific mechanisms that enable the flow of polarization from a source to the target spins. We then give a more detailed analysis of individual hyperpolarization techniques: the mechanisms by which they work, fundamental and technical requirements, characteristic applications, unresolved issues, and possible future directions. We are seeing a continuous growth of activity in the field of spin hyperpolarization, and we expect the field to flourish as new and improved hyperpolarization techniques are implemented. Some key areas for development are in prolonging polarization lifetimes, making hyperpolarization techniques more generally applicable to chemical/biological systems, reducing the technical and equipment requirements, and creating more efficient excitation and detection schemes. We hope this review will facilitate the sharing of knowledge between subfields within the broad topic of hyperpolarization, to help overcome existing challenges in magnetic resonance and enable novel applications.
Collapse
Affiliation(s)
- James Eills
- Institute
for Bioengineering of Catalonia, Barcelona
Institute of Science and Technology, 08028Barcelona, Spain,
| | - Dmitry Budker
- Johannes
Gutenberg-Universität Mainz, 55128Mainz, Germany,Helmholtz-Institut,
GSI Helmholtzzentrum für Schwerionenforschung, 55128Mainz, Germany,Department
of Physics, UC Berkeley, Berkeley, California94720, United States
| | - Silvia Cavagnero
- Department
of Chemistry, University of Wisconsin, Madison, Madison, Wisconsin53706, United States
| | - Eduard Y. Chekmenev
- Department
of Chemistry, Integrative Biosciences (IBio), Karmanos Cancer Institute
(KCI), Wayne State University, Detroit, Michigan48202, United States,Russian
Academy of Sciences, Moscow119991, Russia
| | - Stuart J. Elliott
- Molecular
Sciences Research Hub, Imperial College
London, LondonW12 0BZ, United Kingdom
| | - Sami Jannin
- Centre
de RMN à Hauts Champs de Lyon, Université
de Lyon, CNRS, ENS Lyon, Université Lyon 1, 69100Villeurbanne, France
| | - Anne Lesage
- Centre
de RMN à Hauts Champs de Lyon, Université
de Lyon, CNRS, ENS Lyon, Université Lyon 1, 69100Villeurbanne, France
| | - Jörg Matysik
- Institut
für Analytische Chemie, Universität
Leipzig, Linnéstr. 3, 04103Leipzig, Germany
| | - Thomas Meersmann
- Sir
Peter Mansfield Imaging Centre, University Park, School of Medicine, University of Nottingham, NottinghamNG7 2RD, United Kingdom
| | - Thomas Prisner
- Institute
of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic
Resonance, Goethe University Frankfurt, , 60438Frankfurt
am Main, Germany
| | - Jeffrey A. Reimer
- Department
of Chemical and Biomolecular Engineering, UC Berkeley, and Materials Science Division, Lawrence Berkeley National
Laboratory, Berkeley, California94720, United States
| | - Hanming Yang
- Department
of Chemistry, University of Wisconsin, Madison, Madison, Wisconsin53706, United States
| | - Igor V. Koptyug
- International Tomography Center, Siberian
Branch of the Russian Academy
of Sciences, 630090Novosibirsk, Russia,
| |
Collapse
|
7
|
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.
Collapse
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.)
| |
Collapse
|
8
|
Sweger S, Denysenkov V, Maibaum L, Prisner T, Stoll S. The effect of spin polarization on double electron-electron resonance (DEER) spectroscopy. MAGNETIC RESONANCE (GOTTINGEN, GERMANY) 2022; 3:101-110. [PMID: 37905182 PMCID: PMC10583274 DOI: 10.5194/mr-3-101-2022] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 06/17/2022] [Indexed: 11/02/2023]
Abstract
Double electron-electron resonance (DEER) spectroscopy measures the distribution of distances between two electron spins in the nanometer range, often on doubly spin-labeled proteins, via the modulation of a refocused spin echo by the dipolar interaction between the spins. DEER is commonly conducted under conditions where the polarization of the spins is small. Here, we examine the DEER signal under conditions of high spin polarization, thermally obtainable at low temperatures and high magnetic fields, and show that the signal acquires a polarization-dependent out-of-phase component both for the intramolecular and intermolecular contributions. For the latter, this corresponds to a phase shift of the spin echo that is linear in the pump pulse position. We derive a compact analytical form of this phase shift and show experimental measurements using monoradical and biradical nitroxides at several fields and temperatures. The effect highlights a novel aspect of the fundamental spin physics underlying DEER spectroscopy.
Collapse
Affiliation(s)
- Sarah R. Sweger
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Vasyl P. Denysenkov
- Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance, Goethe University Frankfurt am Main, Frankfurt, Germany
| | - Lutz Maibaum
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Thomas F. Prisner
- Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance, Goethe University Frankfurt am Main, Frankfurt, Germany
| | - Stefan Stoll
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA
| |
Collapse
|
9
|
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.
Collapse
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.
| | | |
Collapse
|
10
|
Timofeev IO, Politanskaya LV, Tretyakov EV, Polienko YF, Tormyshev VM, Bagryanskaya E, Krumkacheva OA, Fedin MV. Fullerene-based triplet spin labels: methodology aspects for pulsed dipolar EPR spectroscopy. Phys Chem Chem Phys 2022; 24:4475-4484. [DOI: 10.1039/d1cp05545c] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Triplet states of photoexcited organic molecules are promising spin labels with advanced spectroscopic properties for Pulsed Dipolar Electron Paramagnetic Resonance (PD EPR) spectroscopy. Recently proposed triplet fullerene labels have shown...
Collapse
|
11
|
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.
Collapse
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
| |
Collapse
|
12
|
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.
Collapse
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
| |
Collapse
|
13
|
Dale MW, Cheney DJ, Vallotto C, Wedge CJ. Viscosity effects on optically generated electron and nuclear spin hyperpolarization. Phys Chem Chem Phys 2020; 22:28173-28182. [PMID: 33291127 DOI: 10.1039/d0cp04012f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Spin hyperpolarization can dramatically increase signal intensities in magnetic resonance experiments, providing either improved bulk sensitivity or additional spectroscopic detail through selective enhancements. While typical hyperpolarization approaches have utilized microwave irradiation, one emerging route is the use of optically generated triplet states. We report an investigation into the effects of solution viscosity on radical-triplet pair interactions, propose a new standard for quantification of the hyperpolarization in EPR experiments, and demonstrate a significant increase in the optically generated 1H NMR signal enhancement upon addition of glycerol to aqueous solutions.
Collapse
Affiliation(s)
- Matthew W Dale
- Department of Physics, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK
| | | | | | | |
Collapse
|
14
|
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.
Collapse
Affiliation(s)
- Lara Williams
- Department of Chemistry and Konstanz Research School Chemical Biology (KoRS-CB), University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany.
| | | | | | | | | |
Collapse
|
15
|
Sannikova NE, Timofeev IO, Chubarov AS, Lebedeva NS, Semeikin AS, Kirilyuk IA, Tsentalovich YP, Fedin MV, Bagryanskaya EG, Krumkacheva OA. Application of EPR to porphyrin-protein agents for photodynamic therapy. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2020; 211:112008. [PMID: 32932136 DOI: 10.1016/j.jphotobiol.2020.112008] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 07/17/2020] [Accepted: 08/21/2020] [Indexed: 12/19/2022]
Abstract
Recently, a new type of spin labels based on photoexcited triplet molecules was proposed for nanometer scale distance measurements by pulsed dipolar electron paramagnetic resonance (PD EPR). However, such molecules are also actively used within biological complexes as photosensitizers for photodynamic therapy (PDT) of cancer. Up to date, the idea of using the photoexcited triplets simultaneously as PDT agents and as spin labels for PD EPR has never been employed. In this work, we demonstrate that PD EPR in conjunction with other methods provides valuable information on the structure and function of PDT candidate complexes, exemplified here with porphyrins bound to human serum albumin (HSA). Two distinct porphyrins with different properties were used: amphiphilic meso-tetrakis(4-hydroxyphenyl)porphyrin (mTHPP) and water soluble cationic meso-tetrakis(N-methyl-4-pyridyl)porphyrin (TMPyP4); HSA was singly nitroxide-labeled to provide a second tag for PD EPR measurements. We found that TMPyP4 locates in a cavity at the center of the four-helix bundle of HSA subdomain IB, close to the interface with solvent, thus being readily accessible to oxygen. As a result, the photolysis of the complex leads to photooxidation of HSA by generated singlet oxygen and causes structural perturbation of the protein. Contrary, in case of mTHPP porphyrin, the binding occurs at the proton-rich pocket of HSA subdomain IIIA, where the access of oxygen to a photosensitizer is hindered. Structural data of PD EPR were supported by other EPR techniques, laser flash photolysis and protein photocleavage studies. Therefore, pulsed EPR on complexes of proteins with photoexcited triplets is a promising approach for gaining structural and functional insights into such PDT agents.
Collapse
Affiliation(s)
| | - Ivan O Timofeev
- International Tomography Center SB RAS, 630090 Novosibirsk, 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
| | | | | | - Igor A Kirilyuk
- 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.
| | - Elena G Bagryanskaya
- N.N. Vorozhtsov Institute of Organic Chemistry SB RAS, 630090 Novosibirsk, Russia.
| | - Olesya A Krumkacheva
- International Tomography Center SB RAS, 630090 Novosibirsk, Russia; Novosibirsk State University, Pirogova Str. 2, Novosibirsk 630090, Russia.
| |
Collapse
|
16
|
Sannikova N, Timofeev I, Bagryanskaya E, Bowman M, Fedin M, Krumkacheva O. Electron Spin Relaxation of Photoexcited Porphyrin in Water-Glycerol Glass. Molecules 2020; 25:E2677. [PMID: 32527023 PMCID: PMC7321249 DOI: 10.3390/molecules25112677] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/05/2020] [Accepted: 06/06/2020] [Indexed: 02/07/2023] Open
Abstract
Recently, the photoexcited triplet state of porphyrin was proposed as a promising spin-label for pulsed dipolar electron paramagnetic resonance (EPR). Herein, we report the factors that determine the electron spin echo dephasing of the photoexcited porphyrin in a water-glycerol matrix. The electron spin relaxation of a water-soluble porphyrin was measured by Q-band EPR, and the temperature dependence and the effect of solvent deuteration on the relaxation times were studied. The phase memory relaxation rate (1/Tm) is noticeably affected by solvent nuclei and is substantially faster in protonated solvents than in deuterated solvents. The Tm is as large as 13-17 μs in deuterated solvent, potentially expanding the range of distances available for measurement by dipole spectroscopy with photoexcited porphyrin. The 1/Tm depends linearly on the degree of solvent deuteration and can be used to probe the environment of a porphyrin in or near a biopolymer, including the solvent accessibility of porphyrins used in photodynamic therapy. We characterized the noncovalent binding of porphyrin to human serum albumin (HSA) from 1/Tm and electron spin echo envelope modulation (ESEEM) and found that porphyrin is quite exposed to solvent on the surface of HSA. The 1/Tm and ESEEM are equally effective and provide complementary methods to determine the solvent accessibility of a porphyrin bound to protein or to determine the location of the porphyrin.
Collapse
Affiliation(s)
- Natalya Sannikova
- International Tomography Center SB RAS, 630090 Novosibirsk, Russia; (N.S.); (I.T.)
| | - Ivan Timofeev
- International Tomography Center SB RAS, 630090 Novosibirsk, Russia; (N.S.); (I.T.)
| | - Elena Bagryanskaya
- N.N. Vorozhtsov Institute of Organic Chemistry SB RAS, 630090 Novosibirsk, Russia
| | - Michael Bowman
- N.N. Vorozhtsov Institute of Organic Chemistry SB RAS, 630090 Novosibirsk, Russia
- Department of Chemistry & Biochemistry, University of Alabama, Tuscaloosa, AL 35487-0336, USA
| | - Matvey Fedin
- International Tomography Center SB RAS, 630090 Novosibirsk, Russia; (N.S.); (I.T.)
| | - Olesya Krumkacheva
- International Tomography Center SB RAS, 630090 Novosibirsk, Russia; (N.S.); (I.T.)
| |
Collapse
|
17
|
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).
Collapse
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
| |
Collapse
|
18
|
Kuzhelev AA, Tormyshev VM, Plyusnin VF, Rogozhnikova OY, Edeleva MV, Veber SL, Bagryanskaya EG. Photochemistry of tris(2,3,5,6-tetrathiaaryl)methyl radicals in various solutions. Phys Chem Chem Phys 2020; 22:1019-1026. [DOI: 10.1039/c9cp06213k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A detailed mechanism of TAM photolysis was studied and includes photoionization of the TAM radical with the formation of carbocation and further conversion of the carbocation under aerobic conditions into quinone-methide and under anaerobic conditions supposedly into an aromatic carbene.
Collapse
Affiliation(s)
- Andrey A. Kuzhelev
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS
- Novosibirsk 630090
- Russia
| | - Victor M. Tormyshev
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS
- Novosibirsk 630090
- Russia
- Novosibirsk State University
- Novosibirsk 630090
| | - Victor F. Plyusnin
- Novosibirsk State University
- Novosibirsk 630090
- Russia
- Voevodsky Institute of Chemical Kinetics and Combustion
- SB RAS
| | - Olga Yu. Rogozhnikova
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS
- Novosibirsk 630090
- Russia
| | - Mariya V. Edeleva
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS
- Novosibirsk 630090
- Russia
- Novosibirsk State University
- Novosibirsk 630090
| | - Sergey L. Veber
- Novosibirsk State University
- Novosibirsk 630090
- Russia
- International Tomography Center SB RAS
- Novosibirsk 630090
| | - Elena G. Bagryanskaya
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS
- Novosibirsk 630090
- Russia
- Novosibirsk State University
- Novosibirsk 630090
| |
Collapse
|