Cis-trans photoisomerization of the chromophore in the green fluorescent protein variant E2GFP: A molecular dynamics study

By force-field molecular dynamics simulations we investigate the dynamics of cis-trans photoisomerization of the chromophore in the GFP mutant E2GFP (F64L/S65T/T203Y), and the rearrangements that allow the protein structure to accommodate the trans form of the chromophore. We find that in this new configuration the chromophore is less well coordinated with the surrounding protein matrix. From this configuration the simulated trans-cis photoisomerization of the chromophore and the associated non-radiative decay are faster than in the cis-trans case.