Time-dependent density-functional approach for biological chromophores: The case of the green fluorescent protein¶
Authors: Miguel A. L. Marques, Xabier López, Daniele Varsano, Alberto Castro, Angel Rubio
DOI: 10.1103/physrevlett.90.258101
Takeaways:
Abstract¶
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.