Origin of the Bathochromic Shift of Astaxanthin in Lobster Protein: 2D Electronic Spectroscopy Investigation of beta-Crustacyanin
Christensson, Niklas ; Zidek, Karel LU ; Magdaong, Nikki Cecil M. ; LaFountain, Amy M. ; Frank, Harry A. and Zigmantas, Donatas LU
(2013)
In The Journal of Physical Chemistry Part B
117(38).
p.11209-11219
- Abstract
- We report on ultrafast spectroscopy study of beta-crustacyanin, the carotenoprotein responsible for the coloration of the lobster shell. beta-Crustacyanin is formed by two closely positioned astaxanthin molecules encapsulated in protein. The 2D electronic spectroscopy together with two-color pump-probe was applied to investigate the electronic structure, the excited-state dynamics, and the influence of the excitonic interaction between the two carotenoids in beta-crustacyanin. By using the similar to 20 Is laser pulses tuned to absorption bands of the S-0-S-2 and S-1-S-n transitions of carotenoids, we were able to trace full excitation relaxation dynamics, starting with S-2-S-1 relaxation on the similar to 30 fs time scale and finishing... (More)
- We report on ultrafast spectroscopy study of beta-crustacyanin, the carotenoprotein responsible for the coloration of the lobster shell. beta-Crustacyanin is formed by two closely positioned astaxanthin molecules encapsulated in protein. The 2D electronic spectroscopy together with two-color pump-probe was applied to investigate the electronic structure, the excited-state dynamics, and the influence of the excitonic interaction between the two carotenoids in beta-crustacyanin. By using the similar to 20 Is laser pulses tuned to absorption bands of the S-0-S-2 and S-1-S-n transitions of carotenoids, we were able to trace full excitation relaxation dynamics, starting with S-2-S-1 relaxation on the similar to 30 fs time scale and finishing with the ground-state recovery of 3.2 ps. Superimposed on the relaxation dynamics in the 2D spectra, we observed long-lived beating signals at the characteristic frequencies of astaxanthin vibrational modes. We assign these oscillations to the ground-state vibrational wavepacket dynamics. All major features of the 2ll spectra, including amplitude and phase maps of the long-lived oscillations, were reproduced by employing the exciton-vibronic model. Consistent modeling of all optical properties of beta-crustacyanin (including absorption and circular dichroism spectra) points to the relatively weak coupling between the two astaxanthin molecules (similar to 250 cm(-1)). This implies that the excitonic coupling provides insignificant contribution to the bathochromic shift in beta-crustacyanin. We discuss the origin of the shift and propose that it is caused by two major effects: conformational changes of astaxanthin molecules (increase in effective conjugation length) together with increased charge-transfer character of the S-2 state. We put the bathochromic shift in the broad perspective of other "blue" carotenoids properties. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/4319332
- author
- Christensson, Niklas
; Zidek, Karel
LU
; Magdaong, Nikki Cecil M.
; LaFountain, Amy M.
; Frank, Harry A.
and Zigmantas, Donatas
LU
- organization
- publishing date
- 2013
- type
- Contribution to journal
- publication status
- published
- subject
- in
- The Journal of Physical Chemistry Part B
- volume
- 117
- issue
- 38
- pages
- 11209 - 11219
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- wos:000330161700026
- scopus:84884948316
- pmid:23510436
- ISSN
- 1520-5207
- DOI
- 10.1021/jp401873k
- language
- English
- LU publication?
- yes
- additional info
- The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Chemical Physics (S) (011001060)
- id
- 7c9fac13-b324-42c5-b83a-b7125dd72f3a (old id 4319332)
- date added to LUP
- 2016-04-01 12:54:30
- date last changed
- 2022-02-11 18:00:57
@article{7c9fac13-b324-42c5-b83a-b7125dd72f3a,
abstract = {{We report on ultrafast spectroscopy study of beta-crustacyanin, the carotenoprotein responsible for the coloration of the lobster shell. beta-Crustacyanin is formed by two closely positioned astaxanthin molecules encapsulated in protein. The 2D electronic spectroscopy together with two-color pump-probe was applied to investigate the electronic structure, the excited-state dynamics, and the influence of the excitonic interaction between the two carotenoids in beta-crustacyanin. By using the similar to 20 Is laser pulses tuned to absorption bands of the S-0-S-2 and S-1-S-n transitions of carotenoids, we were able to trace full excitation relaxation dynamics, starting with S-2-S-1 relaxation on the similar to 30 fs time scale and finishing with the ground-state recovery of 3.2 ps. Superimposed on the relaxation dynamics in the 2D spectra, we observed long-lived beating signals at the characteristic frequencies of astaxanthin vibrational modes. We assign these oscillations to the ground-state vibrational wavepacket dynamics. All major features of the 2ll spectra, including amplitude and phase maps of the long-lived oscillations, were reproduced by employing the exciton-vibronic model. Consistent modeling of all optical properties of beta-crustacyanin (including absorption and circular dichroism spectra) points to the relatively weak coupling between the two astaxanthin molecules (similar to 250 cm(-1)). This implies that the excitonic coupling provides insignificant contribution to the bathochromic shift in beta-crustacyanin. We discuss the origin of the shift and propose that it is caused by two major effects: conformational changes of astaxanthin molecules (increase in effective conjugation length) together with increased charge-transfer character of the S-2 state. We put the bathochromic shift in the broad perspective of other "blue" carotenoids properties.}},
author = {{Christensson, Niklas and Zidek, Karel and Magdaong, Nikki Cecil M. and LaFountain, Amy M. and Frank, Harry A. and Zigmantas, Donatas}},
issn = {{1520-5207}},
language = {{eng}},
number = {{38}},
pages = {{11209--11219}},
publisher = {{The American Chemical Society (ACS)}},
series = {{The Journal of Physical Chemistry Part B}},
title = {{Origin of the Bathochromic Shift of Astaxanthin in Lobster Protein: 2D Electronic Spectroscopy Investigation of beta-Crustacyanin}},
url = {{https://lup.lub.lu.se/search/files/102846875/Christensson2013JPCB.pdf}},
doi = {{10.1021/jp401873k}},
volume = {{117}},
year = {{2013}},
}