Charge transfer states in phycobilisomes

Md Wahadoszamen, Tjaart P.J. Krüger, Anjue Mane Ara, Rienk van Grondelle, Michal Gwizdala*

*Corresponding author for this work

Research output: Contribution to JournalArticleAcademicpeer-review

Abstract

Phycobilisomes (PBs) absorb light and supply downstream photosynthetic processes with excitation energy in many cyanobacteria and algae. In response to a sudden increase in light intensity, excess excitation energy is photoprotectively dissipated in PBs by means of the orange carotenoid protein (OCP)-related mechanism or via a light-activated intrinsic decay channel. Recently, we have identified that both mechanisms are associated with far-red emission states. Here, we investigate the far-red states involved with the light-induced intrinsic mechanism by exploring the energy landscape and electro-optical properties of the pigments in PBs. While Stark spectroscopy showed that the far-red states in PBs exhibit a strong charge-transfer (CT) character at cryogenic temperatures, single molecule spectroscopy revealed that CT states should also be present at room temperature. Owing to the strong environmental sensitivity of CT states, the knowledge gained from this study may contribute to the design of a new generation of fluorescence markers.

Original languageEnglish
Article number148187
Pages (from-to)1-10
Number of pages10
JournalBiochimica et Biophysica Acta - Bioenergetics
Volume1861
Issue number7
Early online date12 Mar 2020
DOIs
Publication statusE-pub ahead of print - 12 Mar 2020

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Keywords

  • Excitation energy flow regulation
  • Light harvesting
  • Photosynthesis
  • Single molecule spectroscopy
  • Stark spectroscopy

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