Excitation Energy Transfer between Higher Excited States of Photosynthetic Pigments: 1. Carotenoids Intercept and Remove B Band Excitations.

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

SUBMITTER: Gotze JP 

PROVIDER: S-EPMC10620780 | biostudies-literature | 2023 Oct

REPOSITORIES: biostudies-literature