User:Dong Woo Chin/Sandbox 1
From Proteopedia
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GFP-based Biosensor
Background
Heavy metals are often harmful to human health because of their toxicities. The detection techniques of heavy metals in food or water have become an essential tool to prevent food-poisoning in public. Modification of GFP is another technique that was recently introduced to detect heavy metals. When a recombinant gene of a GFP-based biosensor is engineered into E. coli with a heavy metal resistant gene, the genetically engineered E. coli fluoresce. This fluorescence is activated even in a very low concentration of a particular heavy metal. Therefore, the development, modification, and application of GFP-based biosensor can improve the public health and protect people from heavy metal related poisonings.
Modifications from GFP
There are two core mutations (Tyrosine-66-Histidine and Tyrosine-145-Phenylalanine) in the zinc biosensor. However, the brightness of the protein could be enhanced with more mutations at F64, F99, H148, M153, and V163 to change them into L64, S99, G148, T153, and A163 (F64L, F99S, H148G, M153T, V163A). S65T, R80Q, and S205C mutations are required for GFP to become a mercury biosensor. A mercury molecule binds to a water molecule and to the mutated Cystein-205. The only common mutation in the zinc and mercury biosensors is Serine-65-Threonine, located at the chromophore.
Applications
Application of the biosensor is not limited to the food-poisoning prevention in the public. Biosensor can be used to measure heavy metal contaminations in soils, to trace heavy metals in a biological system, and to detect explosives. The genetic engineering of GFP gene is essential to reveal the full potential of GFP in its applications.
