E-Locus - Institutional Repository of the University of Crete

Home Search

Results - Details

Search command : Author="Βασιλικογιαννάκης" And Author="Γεώργιος"

Current Record: 9 of 75

[Add to Basket]

Identifier

000454250

Title

Application of Baeyer-Villiger monooxygenases as protein scaffolds in photochemical reactions

Alternative Title

Εφαρμογή Baeyer-Villiger μονοοξυγενασών ως πρωτεϊνική μήτρα σε φωτοχημικές αντιδράσεις

Author

Αγγέλη, Χαριτωμένη Δ.

Thesis advisor

Παυλίδης, Ιωάννης

Reviewer

Βασιλικογιαννάκης, Γεώργιος
Σμόνου, Ιουλία

Abstract

Baeyer-Villiger-Monooxygenases (BVMOs), belong to the large family of Flavoprotein-Monooxygenases (FPMOs) and can catalyze the Baeyer-Villiger oxidation reaction under mild conditions, leading to a sustainable chemical process. Type I BVMOs have FAD as a prosthetic group in their active site, and use NADPH as a coenzyme. They utilize molecular oxygen from air to perform the insertion of an oxygen atom next to a carbonyl group, leading to the formation of an ester or a lactone, often with high enantio- and regioselectivity. However, there are many limitations to the application of BVMOs on an industrial scale, due to their low thermo-, pH-, solvent- and oxidative stability. Herein, we propose that flavin dependent Type I BVMOs can act as protein-based photosensitizers for singlet oxygen generation, which can be utilized in synthetically useful photochemical reactions. The biochemical characterization of several wild-type enzymes available in house, highlighted the instability of these enzymes under conditions employed in photochemical reactions. Thus, Rational Design Mutagenesis was performed on the residues susceptible to oxidation, in order to enhance the stability of the proteins. We managed to construct a thermostable variant of the 2-oxo-Δ³ -4,5,5- trimethylcyclopentenylacetyl-CoA monooxygenase from Pseudomonas putida (OTEMO), with the single mutation C444S. Applying this variant in photochemical reactions, we were able to provide the proof-of-principle of our hypothesis, which was the generation of singlet oxygen in the active site of the BVMO. The photochemical reactions with furan substrates consisted the benchmark reactions, that helped us to understand the principles governing these reactions and expand the substrate portfolio on nonfuran substrates.

Language

English, Greek

Subject

Baeyer-Villiger μονοοξυγενάσες (BVMOS)

Singlet oxygen

Οξυγόνο απλής κατάστασης

Issue date

2023-03-30

Collection

School/Department--School of Sciences and Engineering--Department of Chemistry--Post-graduate theses

Type of Work--Post-graduate theses

Permanent Link