What drives the redox properties of model green fluorescence protein chromophores?

TitleWhat drives the redox properties of model green fluorescence protein chromophores?
Publication TypeJournal Article
Year of Publication2011
AuthorsSolntsev, KM, Ghosh, D, Amador, A, Josowicz, M, Krylov, AI
JournalJournal of Physical Chemistry Letters
Volume2
Issue21
Date PublishedSEP
Abstract

We report the first experimental determination of the oxidation potentials E-ox(0). (relative to the standard hydrogen electrode, SHE) of model green fluorescent protein (GFP) chromophores. Para-, meta, and ortho-hydroxy (4-hydroxybenzylidene-2,3-dimethylimidazolinone, HBDI) and methoxy (MeOBDI) derivatives were studied. E-ox(0) of the three isomers in acetonitrile are -1.31, -1.52, and -1.39 V, respectively. Electronic structure calculations reproduce the observed differences between the isomers and reveal that E-ox(0) follows the ionization energies (IEs), that is, p-MeOBDI has the lowest IE (6.96 eV in the gas phase) due to resonance stabilization of its cation, whereas the resonance is detuned in m-MeOBDL resulting in more-negative E-ox(0). The observed meta and ortho effects in E-ox(0) are similar to the trends in pK(a). The effect of increased solvent polarity on absolute.E-ox(0) (and especially on para-meta-ortho differences) was found to be small. The redox properties of GFP chromophores are driven by their structure and can be correlated with IEs, which can be exploited in predicting the properties of other fluorescent protein chromophores.

DOI10.1021/jz2011397
Type of Journal (Indian or Foreign)

Foreign

Impact Factor (IF)

8.539

Divison category: 
Physical and Materials Chemistry