The overall aim of this fellowship was to develop an enzyme that catalyses the Heck reaction using de novo proteins.
We now live in an age where the consequences of the emissions of greenhouse gases are having observable, detrimental effects on our planet’s ecosystem. Therefore, the need to develop non-toxic, cleaner and lower energy reactions is essential. Palladium(0)-catalysed cross-coupling reactions are a powerful method for generating carbon-carbon and carbon-heteroatom bonds, leading to their extensive use in academia and industry. Among all cross-coupling reactions, it can be argued that the Heck reaction is one of the greenest because the reagents are not prefunctionalised with metals, boron or silicon. Furthermore, it has been demonstrated that the Heck reaction can be performed in water, although truly catalytic examples to date require temperatures up to 140 °C and often more reactive and expensive aryl bromide and aryl iodide reagents.
De novo protein design, the selection of an amino-acid sequence that will fold to a desired protein structure, is a newly established field. Successful designs have furnished a diverse range of protein structures. In contrast to most natural proteins, de novo proteins are well understood, have high thermal stability and are characterised to atomic detail.
Dr Rhys, under the supervision of Prof Höcker & Prof Weber, attempted to purpose a range of natural and de novo proteins to bind artificial co-factors to develop de novo Heckase enzymes. The Covid-19 pandemic was ongoing throughout the two year project. Despite setbacks related to this, and other unforeseeable scientific challenges, we have made significant progress towards the objective of developing an enzyme that can catalyse the Mizoroki-Heck reaction under more environmentally friendly conditions.
