Excited State Vibrations of Isotopically Labeled FMN Free and Bound to a Light-Oxygen-Voltage (LOV) Protein.
J Phys Chem B
; 124(33): 7152-7165, 2020 08 20.
Article
en En
| MEDLINE
| ID: mdl-32786715
ABSTRACT
Flavoproteins are important blue light sensors in photobiology and play a key role in optogenetics. The characterization of their excited state structure and dynamics is thus an important objective. Here, we present a detailed study of excited state vibrational spectra of flavin mononucleotide (FMN), in solution and bound to the LOV-2 (Light-Oxygen-Voltage) domain of Avena sativa phototropin. Vibrational frequencies are determined for the optically excited singlet state and the reactive triplet state, through resonant ultrafast femtosecond stimulated Raman spectroscopy (FSRS). To assign the observed spectra, vibrational frequencies of the excited states are calculated using density functional theory, and both measurement and theory are applied to four different isotopologues of FMN. Excited state mode assignments are refined in both states, and their sensitivity to deuteration and protein environment are investigated. We show that resonant FSRS provides a useful tool for characterizing photoactive flavoproteins and is able to highlight chromophore localized modes and to record hydrogen/deuterium exchange.
Texto completo:
1
Base de datos:
MEDLINE
Asunto principal:
Vibración
/
Mononucleótido de Flavina
Idioma:
En
Revista:
J Phys Chem B
Asunto de la revista:
QUIMICA
Año:
2020
Tipo del documento:
Article
País de afiliación:
Estados Unidos