0603873 - BC 2025 RIV FR eng J - Článek v odborném periodiku
Agostini, Alessandro - Bortolus, M. - Ferlez, B. - Walters, K. - Golbeck, J. H. - van der Est, A. - Carbonera, D.
Differential sensitivity to oxygen among the bacteriochlorophylls g in the type-I reaction centers of Heliobacterium modesticaldum.
Photochemical & Photobiological Sciences. Roč. 20, č. 6 (2021), s. 747-759. ISSN 1474-905X. E-ISSN 1474-9092
Institucionální podpora: RVO:60077344
Klíčová slova: Type-I photosystem * Optically detected magnetic resonance * Triplet state * Bacteriochlorophyll g * Oxygen sensitivity * Chlorophyll a
Obor OECD: Biophysics
Impakt faktor: 4.328, rok: 2021 ; AIS: 0.652, rok: 2021
Způsob publikování: Omezený přístup
Web výsledku:
https://link.springer.com/article/10.1007/s43630-021-00049-3DOI: https://doi.org/10.1007/s43630-021-00049-3

The type-I, homodimeric photosynthetic reaction center (RC) of Heliobacteria (HbRC) is the only known RC in which bacteriochlorophyll g (BChl g) is found. It is also simpler than other RCs, having the smallest number of protein subunits and bound chromophores of any type-I RC. In the presence of oxygen, BChl g isomerizes to 8(1)-hydroxychlorophyll a(F) (Chl a(F)). This naturally occurring process provides a way of altering the chlorophylls and studying the effect of these changes on energy and electron transfer. Transient absorbance difference spectroscopy reveals that triplet-state formation occurs in the antenna chlorophylls of HbRCs but does not provide site-specific information. Here, we report on an extended optically detected magnetic resonance (ODMR) study of the antenna triplet states in HbRCs with differing levels of conversion of BChl g to Chl a(F). The data reveal pools of BChl g molecules with different triplet zero-field splitting parameters and different susceptibilities to chemical oxidation. By relating the detailed spectroscopic characteristics derived from the ODMR data to the recently solved crystallographic structure, we have tentatively identified BChl g molecules in which the probability of triplet formation is high and sites at which BChl g conversion is more likely, providing useful information about the fate of the excitation in the complex.
Trvalý link: https://hdl.handle.net/11104/0361171