Premium
Excited states of GFP chromophore and active site studied by the SAC‐CI method: Effect of protein‐environment and mutations
Author(s) -
Hasegawa JunYa,
Fujimoto Kazuhiro,
Swerts Ben,
Miyahara Tomoo,
Nakatsuji Hiroshi
Publication year - 2007
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.20667
Subject(s) - chromophore , green fluorescent protein , excited state , chemistry , active site , mutation , biophysics , photochemistry , biochemistry , biology , physics , gene , atomic physics , enzyme
Excited states of fluorescent proteins were studied using symmetry‐adapted cluster‐configuration interaction (SAC‐CI) method. Protein‐environmental effect on the excitation and fluorescence energies was investigated. In green fluorescent protein (GFP), the overall protein‐environmental effect on the first excitation energy is not significant. However, glutamine (Glu) 94 and arginine (Arg96) have the red‐shift contribution as reported in a previous study (Laino et al., Chem Phys 2004, 298, 17). The excited states of GFP active site (GFP‐W22‐Ser205‐Glu222‐Ser65) were also calculated. Such large‐scale SAC‐CI calculations were performed with an improved code containing a new algorithm for the perturbation selection. The SAC‐CI results indicate that a charge‐transfer state locates at 4.19 eV, which could be related to the channel of the photochemistry as indicated in a previous experimental study. We also studied the excitation and fluorescence energies of blue fluorescent protein, cyan fluorescent protein, and Y66F. The SAC‐CI results are very close to the experimental ones. The protonation state of blue fluorescent protein was determined. Conformation of cyan fluorescent protein indicated by the present calculation agrees to the experimentally observed structure. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007