Energy transfer from phycobilisomes to photosystem I at 77 K.

ABSTRACT: Phycobilisomes serve as a light-harvesting antenna of both photosystem I (PSI) and II (PSII) in cyanobacteria, yet direct energy transfer from phycobilisomes to PSI is not well documented. Here we recorded picosecond time-resolved fluorescence at wavelengths of 605-760 nm in isolated photosystem I (PSI), phycobilisomes and intact cells of a PSII-deficient mutant of Synechocystis sp. PCC 6803 at 77 K to study excitation energy transfer and trapping. By means of a simultaneous target analysis of the kinetics of isolated complexes and whole cells, the pathways and dynamics of energy transfer in vitro and in vivo were established. We establish that the timescale of the slowest equilibration between different terminal emitters in the phycobilisome is ≈800 ps. It was estimat

SUBMITTER: van Stokkum IHM 

PROVIDER: S-EPMC10702739 | biostudies-literature | 2023

REPOSITORIES: biostudies-literature