The University of Southampton
University of Southampton Institutional Repository

Photoconversion in the red fluorescent protein from the sea anemone Entacmaea quadricolor: is cis-trans isomerization involved?

Loos, D.C., Habuchi, S., Flors, C., Hotta, J-I., Wiedenmann, J., Nienhaus, G.U. and Hofkens, J. (2006) Photoconversion in the red fluorescent protein from the sea anemone Entacmaea quadricolor: is cis-trans isomerization involved? Journal of the American Chemical Society, 128, (19), pp. 6270-6271. (doi:10.1021/ja0545113 S0002-7863(05)04511-7).

Record type: Article


Proteins from the family of the green fluorescent protein (GFP) are presently extensively used in molecular and cellular biology. Recent studies suggest that isomerization of the chromophore occurs upon excitation and is involved in nonradiative deactivation. Using Raman spectroscopy, we report on photoinduced cis-trans isomerization in the red fluorescent protein eqFP611 from the sea anemone Entacmaea quadricolor. The crystal structure of eqFP611 shows that the chemical structure of the chromophore, p-hydroxybenzylidene-imidazolinone with an extended -conjugated system, is nearly identical to the chromophore of other red fluorescent proteins such as DsRed and HcRed. However, the chromophore of eqFP611 has a trans configuration whereas the chromophore of DsRed has a cis configuration. Upon irradiation with 532-nm light, the absorption of eqFP611 peaking at 559 nm diminished, and concomitantly a drastic decrease in the quantum yield of fluorescence as well as more complex decay kinetics was observed. Upon irradiation, changes in the Raman spectrum of eqFP611 were observed, and the relative intensities and peak positions of the irradiated eqFP611 showed striking similarity with the peaks in the Raman spectrum of DsRed. These observations are tentatively interpreted as trans-to-cis isomerization of the chromophore taking place upon irradiation together with the opening of new, nonradiative pathways.

Full text not available from this repository.

More information

Published date: 2006


Local EPrints ID: 51180
ISSN: 0002-7863
PURE UUID: 7c03d147-1685-4aaa-9b79-63f841547097
ORCID for J. Wiedenmann: ORCID iD

Catalogue record

Date deposited: 08 May 2008
Last modified: 17 Jul 2017 14:49

Export record



Author: D.C. Loos
Author: S. Habuchi
Author: C. Flors
Author: J-I. Hotta
Author: J. Wiedenmann ORCID iD
Author: G.U. Nienhaus
Author: J. Hofkens

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton:

ePrints Soton supports OAI 2.0 with a base URL of

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.