Electric Field Effect on trans-p-Hydroxybenzylideneimidazolidinone: A DFT Study and Implication to Green Fluorescent Protein.

In the present study, density function theory ( DFT) calculations were carried out regarding the electric field effect on the trans-p-hydroxybenzylideneimidazolidinone ( HBDI), which represents the green fluorescent protein ( GFP) chromophore. Structures in the absence or presence of electric fields were fully optimized with the CAM-B3LYP functional, and the corresponding absorption properties were obtained by the time-dependent DFT method. It was found that electric field parallel to the x-axis ( Fx) has the strongest effect on the charge distribution, and, hence the structure and dipole moment, of the ground state. Furthermore, the absorption energy of the neutral and anionic HBDI monomer was significantly affected by Fx. [ABSTRACT FROM AUTHOR]