Excitation Energy Transfer Dynamics from Carotenoid to Bacteriochlorophyll a in the LH2 Complex of Rhodobacter sphaeroides: Insights from Reconstitution Experiments with Carotenoids and B800 Bacteriochlorophyll a.

ABSTRACT: Carotenoids are crucial for photosynthesis, playing key roles in light harvesting and photoprotection. In this study, spheroidene and bacteriochlorophyll a (Bchl a) were reconstituted into the chromatophores of the carotenoidless mutant Rhodobacter sphaeroides R26.1, resulting in the preparation of high-quality LH2 complexes. Global and target analyses of transient absorption data revealed that incorporating B800 Bchl a significantly enhances excitation energy transfer (EET) efficiency from carotenoids to Bchl a. EET predominantly occurs from the carotenoid S₂ state, with additional pathways from the S₁ state observed in native LH2. Unique relaxation dynamics were identified, including the generation of the carotenoid S* state in rec

SUBMITTER: Uragami C 

PROVIDER: S-EPMC11858093 | biostudies-literature | 2025 Feb

REPOSITORIES: biostudies-literature