Unravelling Mn₄Ca cluster vibrations in the S₁, S₂ and S₃ states of the Kok-Joliot cycle of photosystem II.

ABSTRACT: Vibrational spectroscopy serves as a powerful tool for characterizing intermediate states within the Kok-Joliot cycle. In this study, we employ a QM/MM molecular dynamics framework to calculate the room temperature infrared absorption spectra of the S₁, S₂, and S₃ states via the Fourier transform of the dipole time auto-correlation function. To better analyze the computational data and assign spectral peaks, we introduce an approach based on dipole-dipole correlation function of cluster moieties of the reaction center. Our analysis reveals variation in the infrared signature of the Mn₄Ca cluster along the Kok-Joliot cycle, attributed to its increasing symmetry and rigidity resulting from the rising oxidation state of the Mn ions. Furthermo

SUBMITTER: Capone M 

PROVIDER: S-EPMC11290063 | biostudies-literature | 2024 Jul

REPOSITORIES: biostudies-literature