Green is good for chemistry Nobel

Three scientists who developed one of the most important tools in biochemistry – green fluorescent protein – have shared the 2008 Nobel Prize for Chemistry.

The trio is Professor Osamu Shimomura of Boston University Medical School, who first isolated GFP from jellyfish; Professor Martin Chalfie from Columbia University, who first demonstrated how to use it as a tag in C. elegans; and Professor Roger Tsien of the University of California San Diego, who showed how GFP fluoresces and added red, yellow and blue to the palette.

Tsien is scheduled to speak at the Australian Health and Medical Research Congress in Brisbane on November 18.

GFP was first observed in Aequorea victoria, a bioluminescent jellyfish found off the west coast of North America, in 1962. Shimomura showed that the active component of the bioluminescence was the aequorin protein, which emits a blue light when it interacts with calcium.

He then found that this blue light was transduced by another protein, now called GFP, producing the distinct green colour observed in the jellyfish.

He then characterised the chemical structure of the fluorescent chromophore.

The gene coding for the protein was cloned by Douglas Prasher in 1985. Martin Chalfie obtained a clone from Prasher in 1992 and expressed it in E. coli, showing that the protein could be used as a universal genetic marker.

He then used it to show gene expression in C. elegans. Roger Tsien also took up the work at this time, expressing it in the yeast S. cerevisiae. Others demonstrated its expression in mammalian cells and Drosophila.

Tsien and colleagues then worked on a mechanistic understanding of the fluorescence properties and developed new GFP variants. He also helped to determine the protein’s crystal structure.