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Excited states of the green fluorescent protein chromophore: Performance of ab initio and semi‐empirical methods
Author(s) -
Wanko Marius,
GarcíaRisueño Pablo,
Rubio Angel
Publication year - 2012
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201100536
Subject(s) - chromophore , time dependent density functional theory , green fluorescent protein , ab initio , excited state , zindo , fluorescence , chemistry , complete active space , computational chemistry , chemical physics , photochemistry , physics , density functional theory , atomic physics , quantum mechanics , molecule , biochemistry , organic chemistry , basis set , gene
The complex photophysical properties of fluorescent proteins give rise to a wide field of applications as markers in molecular biology. Understanding these properties is essential for rational genetic engineering of new fluorescent proteins. Here, theoretical models are required to support the interpretation of structural and spectroscopic experimental data. This requires the accurate and reliable prediction of excited‐state features of the chromophore and its interactions with the protein matrix. Here, we compare calculations of absorption and emission energies of semi‐empirical (OM2/MRCI, ZINDO/S, and TD‐DFTB) and ab initio (SORCI, CC2, and TDDFT) approaches for the HBDI chromophore in vacuo and wild‐type green fluorescent protein (GFP) using QM/MM models. We discuss the influence of electrostatic fields, the chromophore geometry, the size of the QM region, and methodological aspects, in particular charge‐transfer states in TDDFT and the applicability of real‐space TDDFT codes. We revisit previous opposing theoretical studies and benchmark gas‐phase measurements.Proton transfer wire of wild‐type green fluorescent protein (wt‐GFP).