Pushing a PETase to the extremes of NMR – NMRATOMIC

Nearly 90% of the 400 million tonnes of plastics produced in 2022 were derived from fossil sources. Despite numerous efforts over the past decades, only 10% come from recycled sources, whether through mechanical or chemical processes, or the use of bio-based plastics. In addition to reducing the production of new plastics to preserve fossil resources, recycling has the potential to significantly mitigate environmental pollution by limiting the accumulation of plastic waste in landfills (and in the environment, such as oceans) and reducing the need for incineration. One of the most promising strategies for environmentally friendly plastic recycling is the use of biocatalysts, particularly enzymes. Enzymatic recycling is gaining increasing interest due to the optimization of new enzymes (PETases) and the development of industrial processes capable of achieving up to 90% degradation in 10 hours. Enzyme engineering has been accelerated by artificial intelligence and high-throughput screening, surpassing the pace achievable by individual enzyme tests. In addition to X-ray crystallography, commonly used during PETase optimization to rationalize mutations, nuclear magnetic resonance (NMR) has recently been employed to provide complementary atomic-level insights into these enzymes. In this project, we intend to explore PETases using NMR under extreme conditions across a wide temperature range, studying their dynamics on different time scales through low and high-pressure relaxation experiments, and at pressures up to 2.5 kbar to observe the effect on the enzyme's catalytic triad. This project will provide unprecedented insights into PETase dynamics, with the overall goal of linking active site dynamics to the catalytic mechanism.