Properties of the Emitting State of the Green Fluorescent Protein Resolved at the CASPT2//CASSCF/CHARMM Level

Abstract

A "brute-force" ab initio CASPT2//CASSCF/CHARMM computational approach is employed to investigate the properties of the emitting state of the wild-type green fluorescence protein. The results indicate that the emitting moiety corresponds to a slightly perturbed H2O- - -chromophore complex. Thus, the protein matrix seems to be designed in such a way to mimic an environment that is more similar to gas-phase than water solution.