Electron-phonon coupling in cyanobacterial photosystem i

Dmitry A. Cherepanov, Georgy E. Milanovsky, Oksana A. Gopta, Ramakrishnan Balasubramanian, Donald Ashley Bryant, Alexey Yu Semenov, John H. Golbeck

Research output: Contribution to journalArticlepeer-review

10 Scopus citations

Abstract

One of the fundamental problems in biophysics is whether the protein medium at room temperature can be properly treated as a fluid dielectric or whether its dynamics is determined by a highly ordered molecular structure resembling the properties of crystalline and amorphous solids. Here, we measured the recombination between reduced A1 and the oxidized chlorophyll special pair P700 over a wide temperature range using preparations of photosystem I from the cyanobacterium Synechococcus sp. PCC 7002 depleted of the iron-sulfur clusters. We found that the dielectric properties of the protein matrix in early electron transfer reactions of photosystem I resemble the behavior of solids that require an implicit treatment of electron-phonon coupling even at ambient temperatures. The quantum effects of electron-phonon coupling in proteins could account for a variety of phenomena, such as the weak sensitivity of electron transfer in pigment-protein complexes to changing environmental conditions including temperature, driving force, polarity, and chemical composition.

Original languageEnglish (US)
Pages (from-to)7943-7955
Number of pages13
JournalJournal of Physical Chemistry B
Volume122
Issue number33
DOIs
StatePublished - Aug 23 2018

All Science Journal Classification (ASJC) codes

  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films
  • Materials Chemistry

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