We have studied excited-state dynamics of "nonfluorescent" flavoproteins by means of the femtosecond fluorescence up-conversion method. We have interpreted the ultrafast fluorescence quenching mechanisms of these flavoproteins as due to the ultrafast electron transfer or electron transfer followed by proton-transfer interactions between excited flavin chromophore and nearby tryptophan and tyrosine residues placed in the protein nanospace, on the basis of their X-ray structures. Comparisons of fluorescence time profiles and spectral characteristics of flavin chromophores in solutions with those in protein environments have suggested the existence of extremely fast Franck-Condon → fluorescent state relaxations specific to the protein environments. These results of the ultrafast fluorescence dynamics studies on the nonfluorescent flavoproteins have many features in common with other photobiologically important proteins.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
- Materials Chemistry