Excited state reactions in fluorescent proteins

Area of Science:

• Biochemistry
• Biophysics
• Molecular Biology

Background:

• Green fluorescent protein (GFP) is a crucial tool in bioimaging.
• Its applications can be refined by understanding excited state chemistry.
• The photophysics of GFP and its chromophore are complex and varied.

Purpose of the Study:

• To review how GFP applications can be tailored using excited state chemistry.
• To describe the photophysics of the basic chromophore and wild-type GFP.
• To explore the role of excited state proton transfer in GFP and its implications for protein science.

Main Methods:

• Detailed description of GFP chromophore photophysics in solution.
• Characterization of the dominant radiationless decay mechanism.
• Analysis of excited state proton transfer reactions in wild-type GFP and engineered variants.

Main Results:

• The photophysics of the basic chromophore and wild-type GFP differ significantly.
• Excited state proton transfer in GFP serves as a model for protein proton transfer processes.
• Engineered GFPs demonstrate blocked or redirected proton transfer pathways.

Conclusions:

• Knowledge of excited state chemistry allows for tailored GFP applications in bioimaging.
• GFP photophysics, including proton transfer, provides valuable insights into protein mechanisms.
• The review covers fundamental photophysics and emerging photochemically active fluorescent proteins.