Linked Life Data

19606312

Source:http://linkedlifedata.com/resource/pubmed/id/19606312

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
29
pubmed:dateCreated
2009-7-16
pubmed:abstractText
Fluorescent proteins are commonly used as molecular labels, noninvasive markers of gene expression, and reporters of environmental conditions in live cells. We investigate the structural and spectroscopic properties of the chromophore of a far-red fluorescent protein eqFP611. Both the cis and trans isomers of the chromophore are examined within the protein for which both anionic and neutral states of protonation are considered. Spectroscopic properties are examined using time-dependent density functional theory (TDDFT), employing the B3LYP, PBE and B3PW91 density functionals. Intermolecular and long-range contributions to the structure and spectroscopy were treated using the own n-layered integrated molecular orbital and molecular mechanics (ONIOM) approach. The results indicated that the chromophore before excitation is in an anionic, protonated state, with the long-range contributions inducing a blue shift in the absorption and fluorescence maxima of the chromophore. Moreover, the calculated changes of the lowest pi-pi* excitation energy upon isomerization match the observed shift from 559 to 600 nm in the absorption maximum of the system following prolonged irradiation. Furthermore, decomposition analysis of the electrostatic contributions from individual residues indicated that the interactions from four residues Arg92, Lys67, Glu145, and His197 to the chromophore play a key role in the absorption and fluorescence spectra of eqFP611, suggesting that mutations at these sites should provide very useful mechanistic information.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1463-9076
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
11
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6042-50
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
The 559-to-600 nm shift observed in red fluorescent protein eqFP611 is attributed to cis-trans isomerization of the chromophore in an anionic protein pocket.
pubmed:affiliation
Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't