Reversible and irreversible fluorescence activity of the Enhanced Green Fluorescent Protein in pH: Insights for the development of pH-biosensors.

Enhanced Green Fluorescent Protein (EGFP) is a biomolecule with intense and natural fluorescence, with biological and medical applications. Although widely used as a biomarker in research, its application as a biosensor is limited by the lack of in-depth knowledge regarding its structure and behavior in adverse conditions. This study is focused on addressing this need by evaluating EGFP activity and structure at different pH using three-dimensional fluorescence, circular dichroism and small-angle X-ray scattering.

Revealing a new fluorescence peak of the enhanced green fluorescent protein using three-dimensional fluorescence spectroscopy.

Fluorescent proteins have many applications as biomarkers and biosensors in the medical and biological fields. Their success was largely supported by modifications of the first isolated fluorescent protein, the wild-type Green Fluorescent Protein (wtGFP), which allowed the development of improved variants such as the Enhanced GFP (EGFP). The first reports on EGFP indicated that the protein presented a single form and fluorescence peak, in contrast to the two conformations observed in wtGFP.