Energy transfer in the peridinin chlorophyll-a protein of Amphidinium carterae studied by polarized transient absorption and target analysis

Brent P. Krueger, Stefania S. Lampoura, Ivo H M Van Stokkum, Emmanouil Papagiannakis, Jante M. Salverda, Claudiu C. Gradinaru, Danielis Rutkauskas, Roger G. Hiller, Rienk Van Grondelle*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

96 Citations (Scopus)

Abstract

The peridinin chlorophyll-a protein (PCP) of dinoflagellates differs from the well-studied light-harvesting complexes of purple bacteria and green plants in its large (4:1) carotenoid to chlorophyll ratio and the unusual properties of its primary pigment, the carotenoid peridinin. We utilized ultrafast polarized transient absorption spectroscopy to examine the flow of energy in PCP after initial excitation into the strongly allowed peridinin S2 state. Global and target analysis of the isotropic and anisotropic decays reveals that significant excitation (25-50%) is transferred to chlorophyll-a directly from the peridinin S2 state. Because of overlapping positive and negative features, this pathway was unseen in earlier single-wavelength experiments. In addition, the anisotropy remains constant and high in the peridinin population, indicating that energy transfer from peridinin to peridinin represents a minor or negligible pathway. The carotenoids are also coupled directly to chlorophyll-a via a low-lying singlet state S1 or the recently identified SCT. We model this energy transfer time scale as 2.3 ± 0.2 ps, driven by a coupling of ∼47 cm-1. This coupling strength allows us to estimate that the peridinin S1/SCT donor state transition moment is ∼3 D.

Original languageEnglish
Pages (from-to)2843-2855
Number of pages13
JournalBiophysical Journal
Volume80
Issue number6
Publication statusPublished - Jun 2001

Fingerprint Dive into the research topics of 'Energy transfer in the peridinin chlorophyll-a protein of Amphidinium carterae studied by polarized transient absorption and target analysis'. Together they form a unique fingerprint.

Cite this