Chalfie, Martin (1947-…), an American biologist, shared the 2008 Nobel Prize in chemistry with the Japanese-born American chemist Osamu Shimomura and the American chemist Roger Tsien. All three received the award for their work with the green fluorescent protein (GFP). GFP is a naturally occurring molecule that glows green when exposed to blue or ultraviolet light. It can be linked to other proteins, “tagging” them so they can be viewed with a microscope. Chalfie was the first to suggest using GFP in this way.
Shimomura announced the discovery of GFP in 1962. He isolated it from the glowing cells of the jellyfish Aequorea victoria. He later found GFP to have unique qualities. Most importantly, in the 1970’s, he showed that once GFP was made in the jellyfish, it did not require energy-giving molecules to glow. Many other molecules that glow need additional energy to do so, but GFP does not. He also discovered GFP to be small compared with other glowing molecules.
In 1988, Chalfie recognized that these qualities make GFP an ideal protein “tag”. Before tagging a protein though, Chalfie first replaced the protein. He did this by replacing the gene for the target protein with the gene for GFP. The result was that wherever the protein would normally be produced, GFP was produced instead. He was then able to observe where the substituted protein would usually appear in the animal with a microscope. Chalfie used this technique to track proteins found in the neurons (nerve cells) of the roundworm Caenorhabditis elegans. He then suggested a method of tagging proteins rather than substituting for them. Because GFP is small, it did not interfere with the normal function of the tagged protein. GFP can also be used to study the movement and function of other proteins, including those involved in such diseases as cancer and Alzheimer’s disease.
Martin Chalfie was born in 1947 and raised in Chicago. He received his doctor’s degree in physiology from Harvard University in 1977. In 1982, he became a professor of biological sciences at Columbia University in New York City.
See also Shimomura, Osamu ; Tsien, Roger Yonchien .
