Mechanistic studies of H2 oxidation and evolution catalysed by NiFe hydrogenase enzymes
<p>The complexity of metalloenzyme catalysis has led to the development of a range of techniques, broadly separated into those that probe activity, and those that provide structural information. However, reconciling data from each of these approaches is challenging due to the differences in th...
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| Format: | Thesis |
| Language: | English |
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2022
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| _version_ | 1817932253770022912 |
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| author | Kendall-Price, S |
| author_facet | Kendall-Price, S |
| author_sort | Kendall-Price, S |
| collection | OXFORD |
| description | <p>The complexity of metalloenzyme catalysis has led to the development of a range of techniques, broadly separated into those that probe activity, and those that provide structural information. However, reconciling data from each of these approaches is challenging due to the differences in the physical form of samples, and that most methods cannot simultaneously provide both structural insight and information on catalytic activity.</p>
<p>Two IR spectroelectrochemical techniques are utilised in this Thesis to provide insight into the catalytic mechanism of [NiFe]-hydrogenases.</p>
<p><i>In situ</i> protein film infra electrochemistry bridges the gap between activity- and spectroscopic-based measurements and has revealed that the rate determining step in H+/H2 catalysis is different for the O2-tolerant Hyd-1 and O2-sensitive Hyd-2.</p>
<p>A technique is developed which combines single crystal IR spectroscopy with electrochemical control to unify structural and spectroscopic information of metalloenzymes. With this technique, a complete redox characterisation of single crystals of <i>E. coli</i> Hyd-1 is described, demonstrating that proton transfer equilibria and electron transfer redox equilibria are maintained in <i>crystallo</i>. Thus the crystalline state can be thought of as a dynamic system, much like in solution.</p>
<p>Studies on single crystals of E. coli Hyd-2 provide evidence of the Nia-L species which was not conclusively identified before for Hyd-2. The observation of the Nia-C species in frozen solution converting into Nia-L upon illumination confirms the assignment of the Nia-L species in Hyd-2.</p>
<p>Overall this work highlights the necessity for utilising a variety of techniques when investigating metalloenzyme catalysis. The single crystal IR microspectroscopic�electrochemical technique developed in this Thesis will provide valuable opportunities for unifying the structural and spectroscopic insights on the catalytic mechanisms of hydrogenases and other metalloenzymes in the future.</p> |
| first_indexed | 2024-03-07T07:48:01Z |
| format | Thesis |
| id | oxford-uuid:23bd0b78-a9d3-4fb4-b350-79b40443a2a7 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-12-09T03:34:59Z |
| publishDate | 2022 |
| record_format | dspace |
| spelling | oxford-uuid:23bd0b78-a9d3-4fb4-b350-79b40443a2a72024-12-01T18:33:28ZMechanistic studies of H2 oxidation and evolution catalysed by NiFe hydrogenase enzymesThesishttp://purl.org/coar/resource_type/c_db06uuid:23bd0b78-a9d3-4fb4-b350-79b40443a2a7Infrared spectroscopyElectrodes, EnzymeBioinorganic chemistryChemistryEnglishHyrax Deposit2022Kendall-Price, S<p>The complexity of metalloenzyme catalysis has led to the development of a range of techniques, broadly separated into those that probe activity, and those that provide structural information. However, reconciling data from each of these approaches is challenging due to the differences in the physical form of samples, and that most methods cannot simultaneously provide both structural insight and information on catalytic activity.</p> <p>Two IR spectroelectrochemical techniques are utilised in this Thesis to provide insight into the catalytic mechanism of [NiFe]-hydrogenases.</p> <p><i>In situ</i> protein film infra electrochemistry bridges the gap between activity- and spectroscopic-based measurements and has revealed that the rate determining step in H+/H2 catalysis is different for the O2-tolerant Hyd-1 and O2-sensitive Hyd-2.</p> <p>A technique is developed which combines single crystal IR spectroscopy with electrochemical control to unify structural and spectroscopic information of metalloenzymes. With this technique, a complete redox characterisation of single crystals of <i>E. coli</i> Hyd-1 is described, demonstrating that proton transfer equilibria and electron transfer redox equilibria are maintained in <i>crystallo</i>. Thus the crystalline state can be thought of as a dynamic system, much like in solution.</p> <p>Studies on single crystals of E. coli Hyd-2 provide evidence of the Nia-L species which was not conclusively identified before for Hyd-2. The observation of the Nia-C species in frozen solution converting into Nia-L upon illumination confirms the assignment of the Nia-L species in Hyd-2.</p> <p>Overall this work highlights the necessity for utilising a variety of techniques when investigating metalloenzyme catalysis. The single crystal IR microspectroscopic�electrochemical technique developed in this Thesis will provide valuable opportunities for unifying the structural and spectroscopic insights on the catalytic mechanisms of hydrogenases and other metalloenzymes in the future.</p> |
| spellingShingle | Infrared spectroscopy Electrodes, Enzyme Bioinorganic chemistry Chemistry Kendall-Price, S Mechanistic studies of H2 oxidation and evolution catalysed by NiFe hydrogenase enzymes |
| title | Mechanistic studies of H2 oxidation and evolution catalysed by NiFe hydrogenase enzymes |
| title_full | Mechanistic studies of H2 oxidation and evolution catalysed by NiFe hydrogenase enzymes |
| title_fullStr | Mechanistic studies of H2 oxidation and evolution catalysed by NiFe hydrogenase enzymes |
| title_full_unstemmed | Mechanistic studies of H2 oxidation and evolution catalysed by NiFe hydrogenase enzymes |
| title_short | Mechanistic studies of H2 oxidation and evolution catalysed by NiFe hydrogenase enzymes |
| title_sort | mechanistic studies of h2 oxidation and evolution catalysed by nife hydrogenase enzymes |
| topic | Infrared spectroscopy Electrodes, Enzyme Bioinorganic chemistry Chemistry |
| work_keys_str_mv | AT kendallprices mechanisticstudiesofh2oxidationandevolutioncatalysedbynifehydrogenaseenzymes |