Newswise – Researchers have created a unique microscopic toolkit of ‘green’ tunable electrical components, paving the way for a new generation of bioelectronic devices and sensors.
The study, led by the University of Bristol, was published today Proceedings of the National Academy of Sciences (PNAS), showing how to make conductive and biodegradable wires from engineered proteins. These would be compatible with traditional electronic components made from copper or iron and the biological machinery responsible for generating energy in all living organisms.
The miniscule wires are about the size of transistors on silicon chips or one-thousandth the width of the finest human hair. They are made entirely of natural amino acids and heme molecules found in proteins such as hemoglobin that carry oxygen in red blood cells. Harmless bacteria were used for their production, eliminating the need for complex and environmentally harmful procedures commonly used in the production of synthetic molecules.
Ross Anderson, professor of biological chemistry at the University of Bristol, said: “Although our designs are inspired by the protein-based electronic circuits required by all life on Earth, they are free from the complexities and instabilities that can prevent us from exploiting their natural equivalents. We can also make these tiny electronic components to order, specifying their properties in a way that natural proteins cannot.
Leading experts in biomolecular engineering and simulation have come together to develop this unique new method for designing tailor-made proteins with tunable electronic properties.
The multidisciplinary team used advanced computational tools to design simple building blocks that can be assembled into long, wire-like protein chains to conduct electrons. They were able to visualize the structure of these wires using protein X-ray crystallography and electron cryo-microscopy (cryo-EM), techniques that allow the structures to be seen in great detail. Pushing the technical boundaries of cryo-EM, the technique obtained images of the smallest individual protein ever studied.
Ultimately, these nanoscale designer wires have the potential to be used in a wide range of applications, including biosensors for detecting diseases and detecting environmental pollutants.
The discovery is expected to lay the foundation for new electrical circuits to create catalysts suitable for green industrial biotechnology and artificial photosynthetic proteins to capture solar energy.
The breakthrough was made possible thanks to a £4.9m grant from the UK’s largest bioscience funder, the Biotechnology and Biological Sciences Research Council (BBSRC). Bristol, Portsmouth, University College, East Anglia (U,CL, University), UK’s largest bioscience funder.
The team used expertise in protein design, electron transfer, biomolecular simulation, structural biology and spectroscopy to gain insight into how electrons flow through natural biomolecules, a process fundamental to cellular respiration and photosynthesis.
Further progress is expected as the project, launched last year, progresses, presenting significant opportunities to assist in the transition to net zero and more sustainable industrial processes.
Adrian Mulholland, professor of chemistry at the University of Bristol, said: “These proteins show how protein design can provide practically useful tools. They offer exciting potential as components of engineering biology and are excellent systems for investigating the fundamental mechanisms of biological electron transfer.
‘An expandable, modular De novo Protein Platform for Precision Redox Engineering’ by George H. Edited by Hutchins, Claire EM Noble, Adrian Bansal et al PNAS