The flow of excitation energy in LHCII monomers: Implications for the structural model of the major plant antenna

Date

1998-12-01

Author

Gradinaru, CC
Ozdemir, S
Gulen, D
van Stokkum, IHM
van Grondelle, R
van Amerongen, H

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

170
views

0
downloads

Spectral and kinetic information on energy transfer within the light-harvesting complex II (LHCII) monomer was obtained from this subpicosecond transient absorption study, by using selective excitation (663, 669, 672, 678, and 682 nm) of various Chl a absorption bands and detecting the induced changes over the entire Q(y) region (650 -700 nm). It is shown that transfer from the pigment(s) absorbing around 663 nm to the low energy ones occurs in 5 +/- 1 ps, whereas the 670-nm excitation is delivered to the same "destination" in two phases (0.30 +/- 0.05 ps, and 12 +/- 2 ps) and a fast equilibration (lifetime 0.45 +/- 0.05 ps) takes place within the main absorption band (675-680 nm). From comparison with results from similar time-resolved measurements on trimeric samples, it can be concluded that the intramonomeric energy transfer completely determines the spectral equilibration observed in native LHCII complexes. To correlate the measured lifetimes and their associated spectra with the pigment organization within the available structural model of LHCII (Kuhlbrandt et. al. 1994. Nature. 367:614-621), extensive but straightforward theoretical modeling was used. Thus it is demonstrated that the pigment assignment (Chl a or Chl b) given by Kuhlbrandt and co-workers cannot simultaneously describe the dichroic spectra and the transient absorption results for the rather homologous LHCII and CP29 proteins. A more recent assignment for CP29, in which a Chl b molecule ("Chl b5") is identified as a Chl a (Dr. R. Bassi, personal communication), leads to a much better description of both CP29 and LHCII. Furthermore, the orientations of the transition dipole moments, which have not been obtained in the crystal structure, are now assigned for most of the Chl's.

Subject Keywords

Light-harvesting-complex, Carotenoids, Fluorescence, Chlorophyll-a, Protein complex, Reaction centers, Chloroplast membranes, Green plants, Photosystem-ii, Transient absorption-spectroscopy

URI

https://hdl.handle.net/11511/68237

Journal

BIOPHYSICAL JOURNAL

DOI

https://doi.org/10.1016/s0006-3495(98)77747-1

Collections

Department of Physics, Article

Suggestions

OpenMETU
Core

The influence of gramicidin S on the thermotropic phase transition of dipalmitoylphosphatidylglycerol DPPG/GS systems: Experiment and computer model Stan, C; Cristescu, CP; Severcan, Feride; Dorohoi, D (2004-09-01) The paper presents experimental data recorded by Fourier Tran form Infrared Spectroscopy regarding the influence of the antimicrobial peptide gramicidin (GS) concentration on the thermotropic phase transition of dipalmitoylphosphatidylglycerol (DPPG) lipid bilayer membrane in DPPG/GS systems, as reflected in the change of the bandwidth of the symmetric stretching band of CH2. The samples were investigated cyclically in a temperature range between 26.5degrees and 61.1degreesC which includes the gel to liquid...
The Effect of Thickness and Doping on the Nonlinear Absorption Behaviour of IIIA-VIA Group Amorphous Semiconductor Thin Films Kurum, Ulas; YAĞLIOĞLU, HALİME GÜL; YÜKSEK, MUSTAFA; ELMALI, Ayhan; Ates, Aytunc; KARABULUT, MEVLÜT; Mamedov, Gasan M.; Hasanlı, Nızamı (2011-06-30) The nonlinear optical absorption of InSe, GaSe and GaxIn1-xSe amorphous films with varying thickness and doping has been studied by open-aperture Z-scan experiment with 4 ns and 65 ps pulse durations at 1064 nm wavelength and femtosecond pump-probe spectroscopy. Our results show that the dopant and film thickness (from 20 nm to 104 nm) results in switching from saturable absorption to nonlinear absorption for equal input intensities. This behaviour is attributed to increasing localized defect states with in...
The structural and electronic properties of BN and BP compounds and BNxP1-x alloys Mohammad, Rezek; Katırcıoğlu, Şenay (Elsevier BV, 2009-06-10) The structural and electronic properties of BN and BP compounds and BNxP1-x alloys have been investigated by full potential linearized augmented plane wave (FP-LAPW) method based on density functional theory (DFT). The total energies and electronic band structures of these compounds have been calculated for different approximations of exchange-correlation energy. The comparative study has showed that the Perdew-Wang-generalized gradient approximation (PW-GGA) is the best one to produce the measured structur...
The structural and electronic properties of BAs and BP compounds and BPxAs1-x alloys Mohammad, Rezek; Katırcıoğlu, Şenay (Elsevier BV, 2009-10-19) The structural and electronic properties of BAs and BP compounds and BPxAs1-x alloys have been investigated by full potential linearized augmented plane wave (FP-LAPW) method based on DFT The total energies and electronic band structures of these compounds have been calculated for different approximations of exchange-correlation energy. The comparative study has showed that the PW-GGA is the best one to produce the measured structural quantities of the compounds. such as the lattice constant, bulk modulus, ...
The effect of dissolved species on hydrophobic aggregation of fluorite Hicyilmaz, C; Bilgen, S; Ozbas, KE (1997-03-10) The hydrophobic aggregation of fluorite in the presence of Fe3+, Al3+, F- Ca2+, Mg2+ and Ba2+ ions was studied. Electrokinetic potentials were measured to interpret the effect of these ions on aggregation.

Citation Formats

C. Gradinaru, S. Ozdemir, D. Gulen, I. van Stokkum, R. van Grondelle, and H. van Amerongen, “The flow of excitation energy in LHCII monomers: Implications for the structural model of the major plant antenna,” BIOPHYSICAL JOURNAL, pp. 3064–3077, 1998, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/68237.