Transforming our understanding of electron transfer in membrane proteins through automation, additive manufacturing and spectroelectrochemistry

Electron transfer processes in membrane proteins underpin fundamentally important biological processes, such as respiration and photosynthesis. Capturing paramagnetic reaction intermediates is key to understanding how these proteins function.

However, capturing truly catalytic intermediates (rather than resting or off-cycle states), while harnessing information on both reactivity and structure, has remained a holy grail.

We will enable the generation and interrogation of such catalytic intermediates in two exemplary and important membrane-bound oxidoreductase enzymes through the development of film-electrochemical EPR (FE-EPR) for membrane proteins.

The challenging physical sciences innovation required to unlock the ability to study the time-dependent nature of these molecular interactions is timely and made possible by developing automated platforms for placing membrane proteins into artificial vesicles which incorporate in situ measurement of protein activity and computer-guided optimization processes, as well as additive manufacturing of tailored electrodes.

Another crucial element is our recent proof-of concept demonstration that small-molecular catalysts can be interrogated with real-time FE-EPR (Nature Chemistry 2024 doi.org/10.1038/s41557-024-01450-y).

The advances in understanding the molecular interactions that underpin respiration and photosynthesis will pave the way to healthy ageing and sustainable agriculture, whilst the methodologies developed will be widely applicable in chemical biology and beyond.