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Lucile Chiari

Development of new biohybrid systems for asymmetric photocatalysis

Published on 7 November 2019
Thesis presented November 07, 2019

For the last decades the development of sustainable chemistry became a priority for our society. In this context, biocatalysis appears to be an interesting solution, through the use of natural, modified or artificial enzymes consisting of a synthetic catalyst grafted into a protein.
In this project, we aim to develop bio-hybrid photocatalysts combining a photosensitizer (RuPhot) and a catalyst (RuCat) within a protein crystal for heterogeneous asymmetric oxidation photocatalysis of organic substrates using water as the only source of oxygen atoms. The selected protein is the oligomerization domain of the Leafy protein of Ginkgo biloba. This protein is able to generate porous structures by self-assembly. Inside the tubes, a peptide chain of about 30 amino acids per monomer is present and it will serve as grafting platform. Three crystalline hybrid systems were obtained with RuPhot and RuCat alone as well as a combination of the two. The characterization was carried out on the RuCat hybrid providing interesting information on the kinetics and selectivity of grafting as well as on a modification of the catalyst during grafting. The studies carried out on the RuPhot hybrids have shown that it was possible, as planned, to graft several chromophores per protein and thus benefit from an antenna effect for maximum efficiency. Catalytic studies for the oxidation of sulphides and alkenes are underway. In a completely different field, 16% of this thesis was devoted to a doctoral consulting contract with the
company NMRBio. The objective was to develop new pathways for the synthesis of stable isotope-labelled compounds in order to perform structural and dynamic NMR studies in proteins.

photocatalysis, oxidation, functional bio-material, bio-inspired

On-line thesis.