Isospectral intermediates in the photochemical reaction cycle of anion channelrhodopsin GtACR1.
Biophys J
; 122(20): 4091-4103, 2023 10 17.
Article
en En
| MEDLINE
| ID: mdl-37749886
ABSTRACT
The most effective tested optogenetic tools available for neuronal silencing are the light-gated anion channel proteins found in the cryptophyte alga Guillardia theta (GtACRs). Molecular mechanisms of GtACRs, including the photointermediates responsible for the open channel state, are of great interest for understanding their exceptional conductance. In this study, the photoreactions of GtACR1 and its D234N, A75E, and S97E mutants were investigated using multichannel time-resolved absorption spectroscopy. For each of the proteins, the analysis showed two early microsecond transitions between K-like and L-like forms and two late millisecond recovery steps. Spectral forms associated with potential molecular intermediates of the proteins were derived and their evolutions in time were analyzed. The results indicate the presence of isospectral intermediates in the photocycles and expand the range of potential intermediates responsible for the open channel state.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Criptófitas
/
Optogenética
Idioma:
En
Revista:
Biophys J
Año:
2023
Tipo del documento:
Article