Time-dependent Density-functional approach for biological photoreceptors: the case of the Green Fluorescent Protein

Physical Review Letters 90, 258101 - 4 (2003)

Time-dependent Density-functional approach for biological photoreceptors: the case of the Green Fluorescent Protein

M.A.L. Marques, X. López, D. Varsano, A. Castro, A. Rubio

We performed first-principles calculations of the optical response of the green fluorescent protein (GFP) within a combined quantum-mechanical molecular-mechanics and time-dependent density-functional theory approach. The computed spectra are in excellent agreement with experiments assuming the presence of two, protonated and deprotonated, forms of the photoreceptor in a ~4∶1 ratio, which supports the conformation model of photodynamics in GFP. Furthermore, we discuss charge transfer, isomerization, and environment effects. The present approach allows for systematic studies of excited-state electron-ion dynamics in biological systems.

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http://dx.doi.org/10.1103/PhysRevLett.90.258101

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