Light-induced pulsed dipolar spectroscopy and other electron spin resonance studies of photogenerated paramagnetic species
<p>This thesis is concerned with the development of new methodologies in the field of Light-induced Pulsed Electron Spin Resonance Dipolar Spectroscopy (LiPDS), with the aim of applying them to the structural investigation of complex biological macromolecular systems with endogenous or artific...
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| Format: | Thesis |
| Language: | English |
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2022
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| _version_ | 1826310081401061376 |
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| author | Bertran, A |
| author2 | Timmel, C |
| author_facet | Timmel, C Bertran, A |
| author_sort | Bertran, A |
| collection | OXFORD |
| description | <p>This thesis is concerned with the development of new methodologies in the field of Light-induced Pulsed Electron Spin Resonance Dipolar Spectroscopy (LiPDS), with the aim of applying them to the structural investigation of complex biological macromolecular systems with endogenous or artificially-added chromophores that can be photoexcited to form triplet states.</p>
<p>The orientational effects in previously reported LiPDS techniques and how to exploit them to extract additional molecular conformational information are explored in Chapter 2. The ReLaserIMD and LiDEER techniques are combined to fully characterise the relative orientation of the two spin centres in porphyrin-nitroxide model peptides, and a new two-dimensional LiPDS technique (frequency-correlated ReLaserIMD) is introduced to capture the complete orientational dependence of the dipolar interaction with a single experiment. These novel methodologies are extended to non-porphyrin chromophores.</p>
<p>Chapter 3 goes a step further to tackle the challenge of measuring the dipolar interaction between two photogenerated triplets, removing the need for having any permanent spin centre in LiPDS. The new Light-Induced Triplet-Triplet Electron Resonance spectroscopy (LITTER) technique is developed using bis-porphyrin model peptides and an in-depth conformational study of a spectroscopic molecular ruler is performed exploiting the orientational effects. LITTER is also compared to conventional DEER spectroscopy, showing superior results, and is applied to the structural study of a dimeric heme protein and a supramolecular porphyrin tetramer.</p>
<p>Chapter 4 addresses some of the limitation of the LITTER technique by using non-identical chromophores and two-colour photoexcitation in bis-labelled model peptides, improved performance and direct combination with F¨orster Resonance Energy Transfer.</p>
<p>This thesis constitutes an important step forward in the knowledge and development of the novel field of LiPDS, by introducing new triplet spin labels, improving existing techniques, developing new experiments and analysis methods, and combining them with other experimental tools for integrative structural biology.</p> |
| first_indexed | 2024-03-07T07:46:53Z |
| format | Thesis |
| id | oxford-uuid:65c7f9c8-7825-4efa-bf92-bb21c05f3990 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T07:46:53Z |
| publishDate | 2022 |
| record_format | dspace |
| spelling | oxford-uuid:65c7f9c8-7825-4efa-bf92-bb21c05f39902023-06-12T08:52:44ZLight-induced pulsed dipolar spectroscopy and other electron spin resonance studies of photogenerated paramagnetic speciesThesishttp://purl.org/coar/resource_type/c_db06uuid:65c7f9c8-7825-4efa-bf92-bb21c05f3990PhotochemistryMolecular structureElectron paramagnetic resonance spectroscopySpin labelsEnglishHyrax Deposit2022Bertran, ATimmel, CBowen, AHore, PCarbonera, D<p>This thesis is concerned with the development of new methodologies in the field of Light-induced Pulsed Electron Spin Resonance Dipolar Spectroscopy (LiPDS), with the aim of applying them to the structural investigation of complex biological macromolecular systems with endogenous or artificially-added chromophores that can be photoexcited to form triplet states.</p> <p>The orientational effects in previously reported LiPDS techniques and how to exploit them to extract additional molecular conformational information are explored in Chapter 2. The ReLaserIMD and LiDEER techniques are combined to fully characterise the relative orientation of the two spin centres in porphyrin-nitroxide model peptides, and a new two-dimensional LiPDS technique (frequency-correlated ReLaserIMD) is introduced to capture the complete orientational dependence of the dipolar interaction with a single experiment. These novel methodologies are extended to non-porphyrin chromophores.</p> <p>Chapter 3 goes a step further to tackle the challenge of measuring the dipolar interaction between two photogenerated triplets, removing the need for having any permanent spin centre in LiPDS. The new Light-Induced Triplet-Triplet Electron Resonance spectroscopy (LITTER) technique is developed using bis-porphyrin model peptides and an in-depth conformational study of a spectroscopic molecular ruler is performed exploiting the orientational effects. LITTER is also compared to conventional DEER spectroscopy, showing superior results, and is applied to the structural study of a dimeric heme protein and a supramolecular porphyrin tetramer.</p> <p>Chapter 4 addresses some of the limitation of the LITTER technique by using non-identical chromophores and two-colour photoexcitation in bis-labelled model peptides, improved performance and direct combination with F¨orster Resonance Energy Transfer.</p> <p>This thesis constitutes an important step forward in the knowledge and development of the novel field of LiPDS, by introducing new triplet spin labels, improving existing techniques, developing new experiments and analysis methods, and combining them with other experimental tools for integrative structural biology.</p> |
| spellingShingle | Photochemistry Molecular structure Electron paramagnetic resonance spectroscopy Spin labels Bertran, A Light-induced pulsed dipolar spectroscopy and other electron spin resonance studies of photogenerated paramagnetic species |
| title | Light-induced pulsed dipolar spectroscopy and other electron spin resonance studies of photogenerated paramagnetic species |
| title_full | Light-induced pulsed dipolar spectroscopy and other electron spin resonance studies of photogenerated paramagnetic species |
| title_fullStr | Light-induced pulsed dipolar spectroscopy and other electron spin resonance studies of photogenerated paramagnetic species |
| title_full_unstemmed | Light-induced pulsed dipolar spectroscopy and other electron spin resonance studies of photogenerated paramagnetic species |
| title_short | Light-induced pulsed dipolar spectroscopy and other electron spin resonance studies of photogenerated paramagnetic species |
| title_sort | light induced pulsed dipolar spectroscopy and other electron spin resonance studies of photogenerated paramagnetic species |
| topic | Photochemistry Molecular structure Electron paramagnetic resonance spectroscopy Spin labels |
| work_keys_str_mv | AT bertrana lightinducedpulseddipolarspectroscopyandotherelectronspinresonancestudiesofphotogeneratedparamagneticspecies |