Single Molecule Spectroscopy of Monomeric LHCII: Experiment and Theory

P. Malý, J.M. Gruber, R. van Grondelle, T. Mancal

Research output: Contribution to JournalArticleAcademicpeer-review

Abstract

We derive approximate equations of motion for excited state dynamics of a multilevel open quantum system weakly interacting with light to describe fluorescence-detected single molecule spectra. Based on the Frenkel exciton theory, we construct a model for the chlorophyll part of the LHCII complex of higher plants and its interaction with previously proposed excitation quencher in the form of the lutein molecule Lut 1. The resulting description is valid over a broad range of timescales relevant for single molecule spectroscopy, i.e. from ps to minutes. Validity of these equations is demonstrated by comparing simulations of ensemble and single-molecule spectra of monomeric LHCII with experiments. Using a conformational change of the LHCII protein as a switching mechanism, the intensity and spectral time traces of individual LHCII complexes are simulated, and the experimental statistical distributions are reproduced. Based on our model, it is shown that with reasonable assumptions about its interaction with chlorophylls, Lut 1 can act as an efficient fluorescence quencher in LHCII.
Original languageEnglish
Article number26230
JournalScientific Reports
Volume6
DOIs
Publication statusPublished - 2016

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chlorophylls
spectroscopy
molecules
fluorescence
statistical distributions
excitation
equations of motion
excitons
interactions
proteins
simulation

Cite this

@article{a52e80e716c24dccaf2edb393aa8733d,
title = "Single Molecule Spectroscopy of Monomeric LHCII: Experiment and Theory",
abstract = "We derive approximate equations of motion for excited state dynamics of a multilevel open quantum system weakly interacting with light to describe fluorescence-detected single molecule spectra. Based on the Frenkel exciton theory, we construct a model for the chlorophyll part of the LHCII complex of higher plants and its interaction with previously proposed excitation quencher in the form of the lutein molecule Lut 1. The resulting description is valid over a broad range of timescales relevant for single molecule spectroscopy, i.e. from ps to minutes. Validity of these equations is demonstrated by comparing simulations of ensemble and single-molecule spectra of monomeric LHCII with experiments. Using a conformational change of the LHCII protein as a switching mechanism, the intensity and spectral time traces of individual LHCII complexes are simulated, and the experimental statistical distributions are reproduced. Based on our model, it is shown that with reasonable assumptions about its interaction with chlorophylls, Lut 1 can act as an efficient fluorescence quencher in LHCII.",
author = "P. Mal{\'y} and J.M. Gruber and {van Grondelle}, R. and T. Mancal",
year = "2016",
doi = "10.1038/srep26230",
language = "English",
volume = "6",
journal = "Scientific Reports",
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}

Single Molecule Spectroscopy of Monomeric LHCII: Experiment and Theory. / Malý, P.; Gruber, J.M.; van Grondelle, R.; Mancal, T.

In: Scientific Reports, Vol. 6, 26230, 2016.

Research output: Contribution to JournalArticleAcademicpeer-review

TY - JOUR

T1 - Single Molecule Spectroscopy of Monomeric LHCII: Experiment and Theory

AU - Malý, P.

AU - Gruber, J.M.

AU - van Grondelle, R.

AU - Mancal, T.

PY - 2016

Y1 - 2016

N2 - We derive approximate equations of motion for excited state dynamics of a multilevel open quantum system weakly interacting with light to describe fluorescence-detected single molecule spectra. Based on the Frenkel exciton theory, we construct a model for the chlorophyll part of the LHCII complex of higher plants and its interaction with previously proposed excitation quencher in the form of the lutein molecule Lut 1. The resulting description is valid over a broad range of timescales relevant for single molecule spectroscopy, i.e. from ps to minutes. Validity of these equations is demonstrated by comparing simulations of ensemble and single-molecule spectra of monomeric LHCII with experiments. Using a conformational change of the LHCII protein as a switching mechanism, the intensity and spectral time traces of individual LHCII complexes are simulated, and the experimental statistical distributions are reproduced. Based on our model, it is shown that with reasonable assumptions about its interaction with chlorophylls, Lut 1 can act as an efficient fluorescence quencher in LHCII.

AB - We derive approximate equations of motion for excited state dynamics of a multilevel open quantum system weakly interacting with light to describe fluorescence-detected single molecule spectra. Based on the Frenkel exciton theory, we construct a model for the chlorophyll part of the LHCII complex of higher plants and its interaction with previously proposed excitation quencher in the form of the lutein molecule Lut 1. The resulting description is valid over a broad range of timescales relevant for single molecule spectroscopy, i.e. from ps to minutes. Validity of these equations is demonstrated by comparing simulations of ensemble and single-molecule spectra of monomeric LHCII with experiments. Using a conformational change of the LHCII protein as a switching mechanism, the intensity and spectral time traces of individual LHCII complexes are simulated, and the experimental statistical distributions are reproduced. Based on our model, it is shown that with reasonable assumptions about its interaction with chlorophylls, Lut 1 can act as an efficient fluorescence quencher in LHCII.

U2 - 10.1038/srep26230

DO - 10.1038/srep26230

M3 - Article

VL - 6

JO - Scientific Reports

JF - Scientific Reports

SN - 2045-2322

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