Engineered metal binding sites on green fluorescence protein.
The ability to assay a variety of metals by noninvasive methods has applications in both biomedical and environmental research. Green fluorescent protein (GFP) is a protein isolated from coelenterates that exhibits spontaneous fluorescence. GFP does not require any exogenous cofactors for fluorescence, and can be easily appended to other proteins at the DNA level, producing a fluorescence-labeled target protein in vivo. Metals in close proximity to chromophores are known to quench fluorescence in a distance-dependent fashion. Potential metal binding sites on the surface of GFP have been identified and mutant proteins have been designed, created, and characterized. These metal-binding mutants of GFP exhibit fluorescence quenching at lower transition metal ion concentrations than those of the wild-type protein. These GFP mutants represent a new class of protein-based metal sensors.
Richmond
T A
TA
Joint Science Department, Claremont McKenna, Pitzer, and Scripps Colleges, 925 North Mills Avenue, Claremont, California 91711, USA. richmond@jsd.claremont.edu
Takahashi
T T
TT
Shimkhada
R
R
Bernsdorf
J
J
D001665:Binding Sites; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism*; D008670:Metals / Q000378:metabolism*; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D015202:Protein Engineering / Q000379:methods
D008164:Luminescent Proteins; D008670:Metals; D049452:Green Fluorescent Proteins