Tags

Type your tag names separated by a space and hit enter

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.
Phys Chem Chem Phys 2009; 11(29):6042-50PC

Abstract

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.

Authors+Show Affiliations

Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.No affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

19606312

Citation

Yan, Weizhong, et al. "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." Physical Chemistry Chemical Physics : PCCP, vol. 11, no. 29, 2009, pp. 6042-50.
Yan W, Xie D, Zeng J. 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. Phys Chem Chem Phys. 2009;11(29):6042-50.
Yan, W., Xie, D., & Zeng, J. (2009). 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. Physical Chemistry Chemical Physics : PCCP, 11(29), pp. 6042-50. doi:10.1039/b903544c.
Yan W, Xie D, Zeng J. 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. Phys Chem Chem Phys. 2009 Aug 7;11(29):6042-50. PubMed PMID: 19606312.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - 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. AU - Yan,Weizhong, AU - Xie,Daiqian, AU - Zeng,Jun, Y1 - 2009/05/12/ PY - 2009/7/17/entrez PY - 2009/7/17/pubmed PY - 2009/9/23/medline SP - 6042 EP - 50 JF - Physical chemistry chemical physics : PCCP JO - Phys Chem Chem Phys VL - 11 IS - 29 N2 - 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. SN - 1463-9076 UR - https://www.unboundmedicine.com/medline/citation/19606312/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_ L2 - https://doi.org/10.1039/b903544c DB - PRIME DP - Unbound Medicine ER -