Reengineering the optical absorption cross-section of photosynthetic reaction centers

Palash K. Dutta, Su Lin, Andrey Loskutov, Symon Levenberg, Daniel Jun, Rafael Saer, J. Thomas Beatty, Yan Liu, Hao Yan, Neal W. Woodbury

Research output: Contribution to journalArticle

39 Citations (Scopus)

Abstract

Engineered cysteine residues near the primary electron donor (P) of the reaction center from the purple photosynthetic bacterium Rhodobacter sphaeroides were covalently conjugated to each of several dye molecules in order to explore the geometric design and spectral requirements for energy transfer between an artificial antenna system and the reaction center. An average of 2.5 fluorescent dye molecules were attached at specific locations near P. The enhanced absorbance cross-section afforded by conjugation of Alexa Fluor 660 dyes resulted in a 2.2-fold increase in the formation of reaction center charge-separated state upon intensity-limited excitation at 650 nm. The effective increase in absorbance cross-section resulting from the conjugation of two other dyes, Alexa Fluor 647 and Alexa Fluor 750, was also investigated. The key parameters that dictate the efficiency of dye-to-reaction center energy transfer and subsequent charge separation were examined using both steady-state and time-resolved fluorescence spectroscopy as well as transient absorbance spectroscopy techniques. An understanding of these parameters is an important first step toward developing more complex model light-harvesting systems integrated with reaction centers.

Original languageEnglish
Pages (from-to)4599-4604
Number of pages6
JournalJournal of the American Chemical Society
Volume136
Issue number12
DOIs
Publication statusPublished - Mar 26 2014

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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  • Cite this

    Dutta, P. K., Lin, S., Loskutov, A., Levenberg, S., Jun, D., Saer, R., Beatty, J. T., Liu, Y., Yan, H., & Woodbury, N. W. (2014). Reengineering the optical absorption cross-section of photosynthetic reaction centers. Journal of the American Chemical Society, 136(12), 4599-4604. https://doi.org/10.1021/ja411843k