in vivo catalysis by artificial enzymes for aldehydes production – INCA

New strategies in organic synthesis, following the principles of green chemistry, are required to reach sustainability. In this context, biocatalysis is the most promising approach, while man-made catalysis provides a greater repertoire of reactions. The combination of both domains, illustrated by the design of artificial enzymes, allows the biocatalysis of unnatural products. Several approaches exist based on the use of purified proteins or on the so called whole-cell biocatalysis. The “INCA” project aims at translating the expertise of the consortium in NikA-based artificial metalloenzymes into “in cellulo” substitutes for a better design of challenging synthetic processes. This is attractive from an economical perspective, as it provides a simpler handling of the artificial metalloenzyme and the possibility of evolving it by standard molecular biology and chemistry techniques. Thus, we plan to self-assemble directly in the bacteria an inorganic complex with the overexpressed NikA protein to generate the already known artificial enzyme in situ. A real asset of the project relies on the characterization of the artificial metalloenzyme in vivo by DNP-enhanced NMR. Moreover, aerobic growth conditions should favor oxidative catalysis while cell metabolism should preserve the stability of the environment (pH, redox state) and guarantee the continuous production of NikA. In this project, we will focus on the generation of aldehydes from the oxidative cleavage of alkenes, providing an original biotechnological route for aldehydes synthesis. In the perspective of a sustainable chemistry approach, alkene molecules will be selected from biomass or chemical waste to generate benzaldehyde or vanillin. The challenge and innovation reside in our focus on the cell viability during the targeted reactions, the oxidative aldehyde synthesis pathway, and the in vivo characterization of the protein/inorganic complex assembly.