Efraim Racker
Efraim Racker | |
|---|---|
| Died | September 9, 1991 (aged 78) |
| Nationality | Austrian |
| Known for | Identifying and Factor 1 (F1), the first part of the ATP synthase enzyme to be characterised |
| Awards | Warren Triennial Prize (1974) National Medal of Science (1976) Gairdner Award (1980) |
| Scientific career | |
| Fields | Biochemistry |
Efraim Racker (June 28, 1913 – September 9, 1991) was an Austrian biochemist who was responsible for identifying and purifying Factor 1 (F1), the first part of the ATP synthase enzyme to be characterised. F1 is only a part of a larger ATP synthase complex known as Complex V. It is a peripheral membrane protein attached to component Fo, which is integral to the membrane.[1]
Early life
Efraim Racker was born to a Jewish family in 1913 in
Career
In the U.S., he accepted a position as a research associate in physiology at the
In 1952 he accepted a position at
Racker left the Public Health Research Institute in 1966 to found the biochemistry department at
Discovery
Racker and his associates, Anima Datta, Maynard Pullmand, and Harvey Penefsky, worked to isolate the enzymes involved in ATP synthesis. They observed that isolated mitochondrial fragments were capable of respiration but not able to synthesize ATP. Racker and his co-workers concluded that oxidative phosphorylation could be restored by addition of the supernatant from the centrifuging. The complex making this restoration possible was named Factor 1 or F1 as it is a necessary coupling factor for ATPase activity. This discovery of the first enzyme of oxidative phosphorylation was identified and purified in 1960.[4]
The factor that binds F1 to the membrane, Fo, was discovered later in conjunction with Yasuo Kagawa. This particle was found to be sensitive to the antibiotic oligomycin and thus named Fo. This discovery had the added benefit of silencing any critics of the role of F1 in oxidative phosphorylation because it conferred oligomycin sensitivity on the ATPase activity complex.[4] Once both of these factors were identified Racker was able to confirm Peter D. Mitchell's hypothesis that contrary to popular opinion, ATP synthesis was not coupled to respiration through a high-energy intermediate but instead by a transmembrane proton gradient.[2]
F1 is a critical part of ATP synthesis within the mitochondria. In its absence, Complex V is not able to create the proton gradient necessary to produce ATP.
On September 6, 1991, Racker was felled by a severe stroke, and died in Syracuse three days after.
References
- ^ a b Cox, Michael M. and David L. Nelson. Lehninger Principles of Biochemistry 4th Edition. New York: WH Freeman and Company. 2005
- ^ a b c d e Kresge, Nicole, Robert D. Simoni and Robert L. Hill. "Unraveling the Enzymology of Oxidative Phosphorylation: The Work of Efraim Racker". Journal of Biological Chemistry Vol. 281, Issue 4. January 27, 2006. http://www.jbc.org/cgi/content/full/281/4/e4
- ^ University, Cornell. "Biographical timeline | Efraim Racker". efraimracker.library.cornell.edu. Retrieved March 10, 2016.
- ^ a b c "Efraim Racker". Biographical Memoirs, Volume 70. National Academy of Sciences. 1996. http://www.nap.edu/readingroom/books/biomems/eracker.html
External links
- Biography - The National Academies Press
- Efraim Racker, Scientist and Artist, June 28, 1913 - September 9, 1991, Cornell University Library
- Efraim Racker-Art Albums
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