Insights into the mechanism of lytic polysaccharide monooxygenases through EPR, resonance Raman and X-ray Absorption and Emission spectroscopies
This project is a collaboration between the University of York and Diamond Light Source Ltd. The supervisor at Diamond will be Dr Sofia Diaz-Moreno.
This proposal seeks to use High Energy Resolution Fluorescence Detected X-ray Absorption Spectroscopy (HERFD-XAS) to study the electronic and orbital structure of the active site Cu which is found in a class of enzymes known as lytic polysaccharide monooxygenases (LPMOs). These enzymes, discovered in 2010/11, are currently the centre of worldwide attention for their ability to convert recalcitrant biomass into usable sugars and their essential role in the commercial production of cellulosic bioethanol. LPMOs are also posing new questions about how the active site of these enzymes (a single copper ion ligated by two histidine residues) is able to effect the oxidation of a recalcitrant polysaccharide. The work described in this proposal seeks to address this last question head on, by trapping the highly reactive intermediates that are formed during the catalytic cycle of LPMOs.
In particular the project will:
1) Biochemically prepare 5 different genomic classes of LPMOs
2) Trap by freeze-quench techniques, the short-lived intermediates (expected to be 3 intermediates per enzyme)
3) Use EPR, resonance Raman and X-ray Absorption and Emission spectroscopies to determine the orbital structure ofthe copper active site intermediates, with particular focus on characterising the first ever ’copper-oxyl’ intermediate
4) Use HERFD-XAS to study the fine structure of the Cu valence orbitals, particularly the unusual covalent orbitals thatare formed on reaction with dioxygen
5) Complement the HERFD-XAS studies with DFT calculations to reproduce the energies and intensities of the edgeand pre-edge transitions.
All Chemistry research students have access to our innovative Doctoral Training in Chemistry (iDTC): cohort-based training to support the development of scientific, transferable and employability skills: https://www.york.ac.uk/chemistry/postgraduate/idtc/
The Department of Chemistry holds an Athena SWAN Gold Award and is committed to supporting equality and diversity for all staff and students. The Department strives to provide a working environment which allows all staff and students to contribute fully, to flourish, and to excel: https://www.york.ac.uk/chemistry/ed/. Diamond Light Source Ltd holds an Athena SWAN Bronze Award, demonstrating their commitment to provide equal opportunities and to advance the representation of women in STEM/M subjects: science, technology, engineering, mathematics and medicine.
This PhD will formally start on 1 October 2020. Induction activities will start on 28 September.
The project is fully funded for 4 years by Diamond and a Department of Chemistry Teaching Studentship and covers: (i) a tax-free annual stipend at the rate of £17,246 for 2020/21, (ii) tuition fees at the UK/EU rate, (iii) funding for consumables. You need to submit a separate Teaching Studentship application: https://www.york.ac.uk/chemistry/postgraduate/research/teachingphd/
You need to be eligible to pay tuition fees at the home rate: https://www.york.ac.uk/study/postgraduate-research/fees/status/
• You should hold or expect to receive at least an upper second class degree (or European equivalent https://www.york.ac.uk/study/international/your-country/) in chemistry or a chemical sciences related subject
You should register your interest in the PhD with Diamond in the first instance.
• You should submit a PhD application to to the University of York: https://www.york.ac.uk/study/postgraduate/courses/apply?course=DRPCHESCHE3
• Applicants should submit a Teaching Studentship Application: https://www.york.ac.uk/chemistry/postgraduate/research/teachingphd/
• Supervisors may contact candidates either by email, telephone, web-chat or in person
• Supervisors can nominate up to 2 candidates to be interviewed for the project who will be invited to a panel interview at the University of York
• The awarding committee in consultation with Diamond will award studentships following the panel interviews
• Candidates will be notified of the outcome of the panel’s decision by email
How good is research at University of York in Chemistry?
FTE Category A staff submitted: 47.06
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