Design of a highly specific and noninvasive biosensor suitable for real-time in vivo imaging of mercury (II) uptake.Chapleau, R.R., Blomberg, R., Ford, P.C., Sagermann, M.
(2008) Protein Sci. 17: 614-622
- PubMed: 18305194
- DOI: 10.1110/ps.073358908
- Primary Citation of Related Structures:
- PubMed Abstract:
- Local complexity of amino acid interactions in a protein core.
Jain, R.K.,Ranganathan, R.
(2004) Proc.Natl.Acad.Sci.USA 101: 111
- Crystal structure of the Aequorea victoria green fluorescent protein.
Ormo, M.,Cubitt, A.B.,Kallio, K.,Gross, L.A.,Tsien, R.Y.,Remington, S.J.
(1996) Science 273: 1392
Mercury is a ubiquitous pollutant that when absorbed is extremely toxic to a wide variety of biochemical processes. Mercury (II) is a strong, "invisible" poison that is rapidly absorbed by tissues of the intestinal tract, kidneys, and liver upon inge ...
Mercury is a ubiquitous pollutant that when absorbed is extremely toxic to a wide variety of biochemical processes. Mercury (II) is a strong, "invisible" poison that is rapidly absorbed by tissues of the intestinal tract, kidneys, and liver upon ingestion. In this study, a novel fluorescence-based biosensor is presented that allows for the direct monitoring of the uptake and distribution of the metal under noninvasive in vivo conditions. With the introduction of a cysteine residue at position 205, located in close proximity to the chromophore, the green fluorescent protein (GFP) from Aequorea victoria was converted into a highly specific biosensor for this metal ion. The mutant protein exhibits a dramatic absorbance and fluorescence change upon mercuration at neutral pH. Absorbance and fluorescence properties with respect to the metal concentration exhibit sigmoidal binding behavior with a detection limit in the low nanomolar range. Time-resolved binding studies indicate rapid subsecond binding of the metal to the protein. The crystal structures obtained of mutant eGFP205C indicate a possible access route of the metal into the core of the protein. To our knowledge, this engineered protein is a first example of a biosensor that allows for noninvasive and real-time imaging of mercury uptake in a living cell. A major advantage is that its expression can be genetically controlled in many organisms to enable unprecedented studies of tissue specific mercury uptake.
Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93106-9510, USA.