Born in Königsberg, Germany, Fritz Lipmann earned his medical degree at the University of Berlin in 1922 and, five years later, received his Ph.D. there as well. For the next several years, Lipmann conducted research at Otto Meyerhof's laboratory in Heidelberg, Germany, and taught at the Kaiser Wilhelm Institute in Berlin. In 1932, when the Nazi movement in Germany made life increasingly uncomfortable, he accepted a position with the Carlsberg Foundation in Copenhagen, Denmark. In 1939, Lipmann immigrated to the United States, settling first at the Cornell Medical School and then, two years later, moving on to Harvard (1941-49) and then the staff of Massachusetts General Hospital (1949-57). In 1957, he became Professor of Biochemistry at the Rockefeller Institute in New York.
For a long time, most of Lipmann's research at these institutions centered around carbohydrate metabolism, especially the role played by phosphates. In 1937, Lipmann had discovered, almost by accident, that phosphates were somehow important to the metabolic process. He was not certain exactly what role they played, but believed it had something to do with the delivery of energy to the body's cells. In 1941, he finally came up with some of the answers he had been seeking. He found a molecule that released low-energy phosphate--adenosine monophosphate--and discovered that, during the course of carbohydrate metabolism, the molecule picked up two energy-rich phosphate bonds, and became adenosine triphosphate (ATP), a high-energy configuration that was able to release small traces of energy, when needed, to cells throughout the body.
In 1947, Lipmann made an even more important discovery. Working with pigeon liver extracts, he found a catalytically-active, heat-stable compound that appeared able to control the transfer of acetyl groups from one molecule to another. After isolating the compound and determining its structure (it was composed largely of pantothenic acid, or vitamin B2) he named it coenzyme A (CoA), with the "A" standing for acetylation. Lipmann speculated that CoA probably played an important role in the Krebs cycle, a complicated cycle of fatty acid, carbohydrate and protein oxidation.
Hans Krebs had already shown that lactic acid was broken down to carbon dioxide by way of a two-carbon compound that was part of his cycle. Lipmann believed that Krebs' two-carbon compound needed the help of CoA in order to enter the cycle and, by 1951, proved this to be the case. The two-carbon compound in the Krebs' cycle combined with CoA to form acetylcoenzyme A, a kind of super coenzyme that served as the hub of numerous biochemical reactions. For instance, in 1950, the coenzyme was found by Feodor Lynen (1911-1979) to play a key role in the metabolism of fats.
For his work on coenzyme A, Lipmann received the 1953 Nobel Prize in physiology or medicine, sharing the prize with Krebs. He also received several other honors including membership in the Faraday Society, the Danish Royal Academy of Sciences and the Royal Society of England.
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