Chromophore interactions leading to different absorption spectra in mNeptune1 and mCardinal red fluorescent proteins.
Extensive MD simulations combined with QM/MM calculations have been performed on mNeptune1 and mCardinal red fluorescent proteins to establish the reasons behind the red shift of the excitation wavelength of mCardinal with respect to mNeptune1. In both cases, it is seen that Arg197 stabilizes the chromophore but cannot be described as stabilizing preferentially the excited state because of the anchor point of the interaction. The interactions of the linking bonds to the α-helix of both proteins to the chromophore have been analyzed. It has been found that, besides the presence of a strategically placed residue Gln41 in mCardinal, solvation water molecules play an active role in the energetics of the stabilization of the excited state, which is preferentially stabilized in the case of mCardinal in contrast to mNeptune1.
Departament de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain. ricard.gelabert@uab.cat.
Pau
P
Armengol
Departament de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain. ricard.gelabert@uab.cat.
Ricard
R
Gelabert
Departament de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain. ricard.gelabert@uab.cat.
Miquel
M
Moreno
Departament de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain. ricard.gelabert@uab.cat and Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
José M
JM
Lluch
D008164:Luminescent Proteins / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D055585:Physical Phenomena; D011789:Quantum Theory; D014867:Water; D000097573:Red Fluorescent Protein
D008164:Luminescent Proteins; D014867:Water; D000097573:Red Fluorescent Protein