New Approaches to Investigate Substrate Binding and Reaction Mechanism of CO2-reducing Enzymes

About the Project

Second Supervisor: Dr Emma Hesketh, Leicester Institute for Structural and Chemical Biology, University of Leicester

Global warming driven by rising levels of greenhouse gases, especially CO₂, is one of the greatest challenges of our time. Reducing and recycling atmospheric CO₂ into useful chemical building blocks is central to a sustainable circular energy economy. While synthetic catalysts for CO₂ reduction often face major challenges, nature provides elegant solutions. Certain enzymes — carbon monoxide dehydrogenases (CODH) and formate dehydrogenases (FDH) — achieve highly selective CO₂ conversion with remarkable activity and efficiency under mild conditions. Understanding how these unique biocatalysts work offers enormous potential for guiding the design of next-generation catalysts based on cheap and abundant metals.

This project will investigate the structural and mechanistic basis of natural CO₂-reducing enzymes. Using cutting-edge cryo-electron microscopy (cryo-EM) under anaerobic and substrate-controlled conditions, we will capture key catalytic states of CODH and FDH. These studies will be complemented with electrochemistry, spectroscopy, and computational approaches to build a holistic picture of how CO₂ binds and is transformed into valuable C₁ products. The work will also develop new methodologies, including cryo-EM grid preparation coupled with electrochemical control, to probe enzymes in action with unprecedented precision.

Alongside structural biology, the project will employ molecular biology and protein engineering to produce recombinant CODH and FDH in E. coli. Enzyme variants will be generated through site-directed mutagenesis to stabilise substrate-bound states, enabling detailed characterisation of substrate binding, catalysis, and product release.

This highly interdisciplinary PhD offers training across molecular biology, structural biology, biophysics, chemistry, and computational methods. By uncovering fundamental design principles of natural CO₂-reducing enzymes, the project aims to inspire the development of novel (bio)hybrid catalysts for CO₂ reduction.

Techniques that will be undertaken during the project

• Molecular biology techniques (this includes heterologous protein expression in E. coli, protein purification, genetic modification via site-directed mutagenesis, subcloning, in vitro reconstitution of proteins)
• Spectroscopy: infrared (IR) spectroscopy and electron paramagnetic resonance (EPR)
• Analytical techniques: Electrochemistry
• Structural biology: crystallisation, Cryo-EM, ab initio structure prediction

Enquiries

Project Enquiries to prm28@leicester.ac.uk

To apply please use the application link at the bottom of this web page Chemistry | Postgraduate research | University of Leicester

Funding Notes

This project is only available on a self funded basis or if you have your own sponsorship.