Superexchange Electron Transfer and Protein Matrix in the Charge-Separation Process of Photosynthetic Reaction Centers.

ABSTRACT: In type-II reaction centers, such as photosystem II (PSII) and reaction centers from purple bacteria (PbRC), light-induced charge separation involves electron transfer from pheophytin (Pheo_D1) to quinone (Q_A), occurring near a conserved tryptophan residue (D2-Trp253 in PSII and Trp-M252 in PbRC). This study investigates the route of the Pheo_D1-to-Q_A electron transfer, focusing on the superexchange coupling (|H_{PheoD1···QA}|) in the PSII protein environment. |H_{PheoD1···QA}| is significantly larger for the Pheo_D1-to-Q_A electron transfer via the unoccupied molecular orbitals of D2-Trp253 ([Trp]^•--like intermediate state, 0.73 meV) compared to direct electron transfer (0.13 meV), sugge

SUBMITTER: Saito K 

PROVIDER: S-EPMC11404480 | biostudies-literature | 2024 Sep

REPOSITORIES: biostudies-literature