Applications of light induced Electron Paramagnetic Resonance to biological systems – from structure determination towards biological quantum gates

Project Description

Electron Paramagnetic Resonance (EPR) is a fast-growing technique with applications in diverse fields including structural biology and quantum information processing. It is used to study systems containing unpaired electrons, analogous to NMR.

Understanding the structure of a biological system, or changes under different perturbations, is important for determining functionality. Pulsed dipolar EPR can be used to quantify nanometre distances between spin-centres, chemical moieties with unpaired electrons, by measuring the dipolar interaction between them. Usually spin-centres used in EPR have unpaired electrons in their ground states, e.g. nitroxides, radicals or some metal clusters/ions, and are often added to the system via structure modification (mutagenesis) and tagging.

Recently we have shown that optically-excited triplet-states can be used to measure distances via Light Induced Triplet-Triplet Electron Resonance (LITTER). Two lasers are coupled into the EPR spectrometer, independently forming two triplet-states, and microwave pulses are used to manipulate the electron spins and detect the dipolar interaction between the triplet spin-centres. LITTER has great promise to be applied in biological systems, particularly those with native cofactors, such as heme groups, that can be used to form the optically-generated triplet states. This is advantageous as it does not require modification or tagging of the biological system, which may cause structural changes.

This project will explore the use of LITTER and other light-induced EPR techniques to investigate the structure of different protein systems including Protochlorophyllide Reductase and Morphinioine Reductase using the triplet-states of native cofactors. As cofactors are tightly bound within a protein structure the distribution of distances and dipolar interactions between centres will be well-defined. Polarization of the spin-state population formed on optical excitation can lead to an increase in signal relative to conventional EPR methods. The well-defined dipolar interactions and polarized populations make such systems exciting potential targets for encoding quantum information processing algorithms.

Funding Information

This is a 3.5 year EPSRC studentship. Funding will cover UK tuition fees/stipend only. The University of Manchester aims to support the most outstanding applicants from outside the UK. We are able to offer a limited number of full studentships to be awarded to international applicants. These full studentships will only be awarded to exceptional quality candidates, due to the competitive nature of this scheme.
We expect the programme to commence in September 2021.

Eligibility Requirements

Applicants are expected to hold, or about to obtain, a minimum upper second class undergraduate degree (or equivalent) in Chemistry, Biochemistry, Biophysics or a related discipline. A Masters degree in a relevant subject and/or research experience in spectroscopy, working with lasers, structural biology or related research topic is desirable.

Application Process

Contact for further Information

Dr Alice Bowen – Email: [email protected]

Dr Sam Hay – Email: [email protected]

References

A. Bertran et al.,J. Phys. Chem. Lett. (2021), 12, 1, 80–85
M.G. Dal Farra, et al., Chem. Phys. Chem., (2019), 20(7), 931.
B. Dietzek, et al., Chem. Phys. Chem., (2009), 10(1), 144.
G. Brandariz-de-Pedro, et al., J. Phys. Chem. Lett., (2017), 8(6), 1219.
S. Hardman, et al., Biophys. J., (2013), 105(11), 2549.

To apply for this PhD, please email Alice.bowen@manchester.ac.uk.

Before sending your email, please double check you have followed all guidelines in this listing and have included a reference number if asked to do so.

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