Toward understanding the redox properties of model chromophores from the green fluorescent protein family: An interplay between conjugation, resonance stabilization, and solvent effects

Debashree Ghosh, Atanu Acharya, Subodh C. Tiwari, Anna I. Krylov

Research output: Contribution to journalArticlepeer-review

19 Scopus citations

Abstract

The redox properties of model chromophores from the green fluorescent protein family are characterized computationally using density functional theory with a long-range corrected functional, the equation-of-motion coupled-cluster method, and implicit solvation models. The analysis of electron-donating abilities of the chromophores reveals an intricate interplay between the size of the chromophore, conjugation, resonance stabilization, presence of heteroatoms, and solvent effects. Our best estimates of the gas-phase vertical/adiabatic detachment energies of the deprotonated (i.e., anionic) model red, green, and blue chromophores are 3.27/3.15, 2.79/2.67, and 2.75/2.35 eV, respectively. Vertical/adiabatic ionization energies of the respective protonated (i.e., neutral) species are 7.64/7.35, 7.38/7.15, and 7.70/7.32 eV, respectively. The standard reduction potentials (Ered0) of the anionic (Chr /Chr-) and neutral (Chr+•/Chr) model chromophores in acetonitrile are 0.34/1.40 V (red), 0.22/1.24 V (green), and -0.12/1.02 V (blue), suggesting, counterintuitively, that the red chromophore is more difficult to oxidize than the green and blue ones (in both neutral and deprotonated forms). The respective redox potentials in water follow a similar trend but are more positive than the acetonitrile values.

Original languageEnglish (US)
Pages (from-to)12398-12405
Number of pages8
JournalJournal of Physical Chemistry B
Volume116
Issue number41
DOIs
StatePublished - Oct 18 2012
Externally publishedYes

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films
  • Materials Chemistry

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