dc.contributor.author
Götze, Jan P.
dc.contributor.author
Lokstein, Heiko
dc.date.accessioned
2023-11-16T14:27:05Z
dc.date.available
2023-11-16T14:27:05Z
dc.identifier.uri
https://refubium.fu-berlin.de/handle/fub188/41572
dc.identifier.uri
http://dx.doi.org/10.17169/refubium-41291
dc.description.abstract
Chlorophylls (Chls) are known for fast, subpicosecond internal conversion (IC) from ultraviolet/blue absorbing (“B” or “Soret” states) to the energetically lower, red light-absorbing Q states. Consequently, excitation energy transfer (EET) in photosynthetic pigment–protein complexes involving the B states has so far not been considered. We present, for the first time, a theoretical framework for the existence of B–B EET in tightly coupled Chl aggregates such as photosynthetic pigment–protein complexes. We show that according to a Förster resonance energy transport (FRET) scheme, unmodulated B–B EET has an unexpectedly high range. Unsuppressed, it could pose an existential threat-the damage potential of blue light for photochemical reaction centers (RCs) is well-known. This insight reveals so-far undescribed roles for carotenoids (Crts, cf. previous article in this series) and Chl b (this article) of possibly vital importance. Our model system is the photosynthetic antenna pigment–protein complex (CP29). The focus of the study is on the role of Chl b for EET in the Q and B bands. Further, the initial excited pigment distribution in the B band is computed for relevant solar irradiation and wavelength-centered laser pulses. It is found that both accessory pigment classes compete efficiently with Chl a absorption in the B band, leaving only 40% of B band excitations for Chl a. B state population is preferentially relocated to Chl b after excitation of any Chls, due to a near-perfect match of Chl b B band absorption with Chl a B state emission spectra. This results in an efficient depletion of the Chl a population (0.66 per IC/EET step, as compared to 0.21 in a Chl a-only system). Since Chl b only occurs in the peripheral antenna complexes of plants and algae, and RCs contain only Chl a, this would automatically trap potentially dangerous B state population in the antennae, preventing forwarding to the RCs.
en
dc.format.extent
9 Seiten
dc.rights.uri
https://creativecommons.org/licenses/by-nc-nd/4.0/
dc.subject
Chlorophylls
en
dc.subject
Excitation Energy Transfer
en
dc.subject
Photosynthetic Pigments
en
dc.subject.ddc
500 Naturwissenschaften und Mathematik::540 Chemie::541 Physikalische Chemie
dc.title
Excitation Energy Transfer between Higher Excited States of Photosynthetic Pigments: 2. Chlorophyll b is a B Band Excitation Trap
dc.type
Wissenschaftlicher Artikel
dcterms.bibliographicCitation.doi
10.1021/acsomega.3c05896
dcterms.bibliographicCitation.journaltitle
ACS Omega
dcterms.bibliographicCitation.originalpublishername
American Chemical Society
dcterms.bibliographicCitation.pagestart
40015
dcterms.bibliographicCitation.pageend
40023
dcterms.bibliographicCitation.volume
8
dcterms.bibliographicCitation.url
https://doi.org/10.1021/acsomega.3c05896
refubium.affiliation
Biologie, Chemie, Pharmazie
refubium.affiliation.other
Institut für Chemie und Biochemie
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refubium.funding
Publikationsfonds FU
refubium.note.author
Die Publikation wurde aus Open Access Publikationsgeldern der Freien Universität Berlin gefördert.
de
refubium.resourceType.isindependentpub
no
dcterms.accessRights.openaire
open access
dcterms.isPartOf.eissn
2470-1343