Femtosecond spectroscopy and molecular modeling uncover new insights into flavin photochemistry

Researchers from LOB Ecole Polytechnique and CEA Cadarache uncover the ultrafast photooxidation dynamics of the flavin cofactor in the natural photoenzyme - fatty acid photodecarboxylase (FAP). Using femtosecond transient absorption spectroscopy, the team demonstrates that photoexcitation of the flavin anion radical triggers its oxidation to FAD within only 100 femtoseconds. Remarkably, the process involves the transient formation of a hydrated electron inside the protein—an unprecedented finding supported by extensive molecular modeling. These results reveal new aspects of flavin photochemistry and open possibilities for the design of unconventional photocatalytic systems.This work is published in ScienceAdvances.