Design of Redox Biocatalysis in Deep Eutectic Solvents
October 1, 2022
September 30, 2024
Solvent design and selection with a particular emphasis on their greenness is currently a main focus both in chemo- and biocatalysis. Biocatalysis has traditionally relied on either aqueous- or classical organic media (mainly for hydrolases), or biphasic systems thereof. In this respect, Deep Eutectic Solvents (DESs) have been identified as „the solvents of the 21st century“ and offer a new dimension as ‘Safe- and Green-by-Design’ solvents for biocatalysis. In a nutshell, DESs’ assets are based on their often biogenic origin, and their properties such as melting points below room temperature, low volatility, high thermal stability, tuneability analogous to ionic liquids, biodegradability, large availability at acceptable costs, and straightforward preparation. In particular, the high degree of freedom in designing DESs from a variety of (biogenic) substances enables the creation of a sustainable solvent platform. The enormous potential of DESs for biocatalytic applications has been mainly explored for hydrolases (EC3), after their first application demonstrated in 2008. Different then EC3 enzymes, oxidoreductases (EC1) have only rarely been employed in DESs at predominant amounts. Few examples for the use of alcohol dehydrogenases (ADHs) have been documented (mainly from our previous DFG-funded project) either to demonstrate the use of DESs for organic synthesis while using a DES component as substrate or to understand the effect of different DESs on the activity and stability of a redox enzyme. Redox biocatalysis is still underrepresented for DES-based applications which will be addressed deeply by the interdisciplinary setup of DESiRE. Overall, the here presented follow-up project represents a clear strategy to elucidate the protein-DES-water interactions, which possess a considerable potential for understanding the ADH-catalysis in DESs. Especially the close collaboration between experimental methods and molecular simulations will lead to new insights on different scales. Moreover, this follow-up project will further open new possibilities to evaluate other enzyme classes for the effects of DESs on catalytic performance (activity, stability and selectivity) of enzymes.