Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5375646 | Chemical Physics | 2008 | 8 Pages |
Abstract
Two blue absorbing and emitting mutants (S65G/T203V/E222Q and S65T at pH 5.5) of the green fluorescent protein (GFP) have been investigated through ultrafast time resolved infra-red (TRIR) and fluorescence spectroscopy. In these mutants, in which the excited state proton transfer reaction observed in wild-type GFP has been blocked, the photophysics are dominated by the neutral A state. It was found that the Aâ excited state lifetime is short, indicating that it is relatively less stabilised in the protein matrix than the anionic form. However, the lifetime of the A state can be increased through modifications to the protein structure. The TRIR spectra show that a large shifts in protein vibrational modes on excitation of the A state occurs in both these GFP mutants. This is ascribed to a change in H-bonding interactions between the protein matrix and the excited state.
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Physical and Theoretical Chemistry
Authors
Deborah Stoner-Ma, Andrew A. Jaye, Kate L. Ronayne, Jérôme Nappa, Peter J. Tonge, Stephen R. Meech,