Login / Signup

Influence of Hydrogen Bonds on the Electron-Phonon Coupling Strength/Marker Mode Structure and Charge Separation Rates in Reaction Centers from Rhodobacter sphaeroides.

Anton KhmelnitskiyJoAnn C WilliamsJames P AllenRyszard Jankowiak
Published in: The journal of physical chemistry. B (2019)
Low-temperature persistent and transient hole-burning (HB) spectra are presented for the triple hydrogen-bonded L131LH + M160LH + M197FH mutant of Rhodobacter sphaeroides. These spectra expose the heterogeneous nature of the P-, B-, and H-bands, consistent with a distribution of electron transfer (ET) times and excitation energy transfer (EET) rates. Transient P+QA- holes are observed for fast (tens of picoseconds or faster) ET times and reveal strong coupling to phonons and marker mode(s), while the persistent holes are bleached in a fraction of reaction centers with long-lived excited states characterized by much weaker electron-phonon coupling. Exposed differences in electron-phonon coupling strength, as well as a different coupling to the marker mode(s), appear to affect the ET times. Both resonantly and nonresonantly burned persistent HB spectra show weak blue- (∼150 cm-1) and large, red-shifted (∼300 cm-1) antiholes of the P band. Slower EET times from the H- and B-bands to the special pair dimer provide new insight on the influence of hydrogen bonds on mutation-induced heterogeneity.
Keyphrases
  • electron transfer
  • energy transfer
  • room temperature
  • density functional theory
  • high glucose
  • oxidative stress
  • gene expression
  • blood brain barrier
  • dna methylation
  • molecular dynamics
  • liquid chromatography