Pushing electrons: How does nature make it work in natural two-dimensional solar cells?

Lead supervisor: Dr Matt Johnson, Molecular Biology and Biotechnology
Co-supervisor(s): Professor Neil Hunter, Molecular Biology and Biotechnology; Dr Mark Dickman, Chemical and Biological Engineering

Deadline: Thursday 9 March 2017

Applications for this project have now closed.

Project description

The aim of the project is to characterise the molecular interactions at the single molecule level that govern the transient interface between the electron donor plastocyanin and photosystem I or cytochrome b6f, during photosynthesis in plants, algae and cyanobacteria. Specifically the project will investigate the timescales of the protein conformational changes and electron transfer reactions involved and their environmental dependence using nanoelectrical and nanomechanical atomic force microscopy and further characterize the exact molecular interactions via cross-linking and mass spectrometry.

Electron transfer reactions are the basis of photosynthesis and respiration, which power all life on Earth. In essence energy directly provided by the sun or from foodstuffs is used to move electrons along a chain of proteins; some of these proteins can move freely, shuttling back and forth carrying their cargo of electrons to and from other proteins that are held in position within a thin sheet of membrane. The mystery is how a freely-moving protein finds its way to a particular membrane-attached protein, how it docks at the membrane surface, releases its electron and then manages to undock, all in a few milliseconds. Yet without hundreds of these electron transfer reactions happening every second, life on Earth could not be sustained. Somehow these pairs of proteins balance two conflicting requirements: they have to come together quickly and specifically to transfer electrons, yet they also have to be able to separate rapidly afterwards. So whatever forces brought the proteins together in the first place can be switched into reverse – how is this possible? What is this switch? Finding this out is the purpose of the proposed research, and it has important implications for all energy-yielding electron transfers on Earth.

Keywords: photosynthesis, electron transfer, atomic force microscopy, mass spectrometry, membrane biochemistry

Subject areas: Biochemistry, Biophysics, Plant Science, Structural Biology, Nanotechnology

Funding notes

This four-year studentship will be fully funded at Home/EU or international rates. Support for travel and consumables (RTSG) will also be made available at standard rate of £2,627 per annum, with an additional one-off allowance of £1,000 for a computer in the first year.  Students will receive an annual stipend of £17,336.