ИСТИНА

A lot of effort is spent nowadays to reveal the full potential of the fluorescent proteins which are widely used as fluorescent markers in cell biology. Modeling their spectra is coupled with many difficulties. It is known, that the protein environment can significantly shift their absorption/emission maxima. Therefore, an isolated chromophore model is not suitable for precise calculations. In present work we have studied the chromophore of the promising fluorescent protein asCP and the influence of nearby residues on its absorption spectra. We have obtained energies of the S0-S1 electronic transitions using the XMCQDPT2/CASSCF(16,14)/ccpVDZ approach [1] for the model systems that contain chromophore within various environment. Our results reveal an impact of the Hbonded individual residues as well as the whole protein on the chromophore spectra.