Cori, Carl and Gerty

Cori, Carl and Gerty

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AMERICAN BIOCHEMISTS
1896–1984 (CARL) 1896–1957 (GERTY)

Carl and Gerty Cori were a husband-and-wife team who worked closely together on research into carbohydrate metabolism.

Carl and Gerty were born in Prague, Czechoslovakia, and met as students at the German University of Prague where they both earned medical degrees in 1920. They were married that same year and migrated to the United States in 1923, both joining a research institute in Buffalo, New York. They became naturalized citizens of the United States in 1928.

In 1931 Carl accepted a position as professor of biochemistry at Washington University Medical School in St. Louis and Gerty was appointed as a research associate. She eventually achieved the rank of professor of biochemistry in 1947. The focus of their research was carbohydrate (sugar) metabolism and the influence of various hormones on these metabolic pathways.

In 1936 they discovered the previously unknown metabolic intermediate glucose-1-phosphate, known as the "Cori ester." (See Figure 1).

Research into the formation of this ester demonstrated that it was formed from glycogen, a polymer of glucose employed by many living system as way to store energy. Over the next few years the Coris demonstrated the existence of a new enzyme, polysaccharide phosphorylase, which catalyzes both the formation of glucose-1-phosphate from glycogen and the reverse reaction in which glucose-1-phosphate is incorporated into glycogen; they also succeeded in purifying the enzyme. Since many enzyme-catalyzed reactions are reversible, demonstration of the pathways required ingenious use of selective enzyme inhibitors that permitted the Coris to demonstrate distinct reactions and isolate the enzymes carrying out the reactions. They eventually linked the formation of glucose-1-phosphate from glycogen in the liver to the transport of glucose to muscle cells where, under anaerobic conditions, glucose can be used as an energy source resulting in the formation of lactic acid. The lactic acid can then be transported back to the liver and, through a series of reactions, be used to reform glycogen. This pathway is known as the Cori cycle. The importance of the Coris's work was recognized when they received the Nobel Prize for physiology or medicine in 1947.

The Coris were also noted for their work investigating the influence of various hormones on carbohydrate metabolism. For example, they demonstrated that epinephrine, a hormone released by the adrenal gland, stimulates the formation of an enzyme that forms glucose from glycogen. They also discovered that insulin stimulates the enzyme hexokinase, which promotes the formation of glycogen from glucose and that a hormone released by the pituitary inhibits the activity of this enzyme. For this and other work the Coris received the Squibb Award in Endocrinology; Gerty was awarded

the Garvan Medal of the American Chemical Society as well as a number of other awards and prizes.

After Gerty's death in 1957, Carl continued his work on the mechanism of enzymes involved in carbohydrate metabolism and remarried in 1960. He continued to publish the results of his research into the early 1980s until shortly before his death in 1984.

see also Enzymes; Krebs Cycle.

Robert K. Griffith

Bibliography

Porter, Roy, ed. (1994). "Cori, Carl Ferdinand and Gerty Theresa," in The Biographical Dictionary of Scientists, 2nd editon, p. 144. New York: Oxford University Press.

Internet Resources

"The Nobel Prize in Physiology or Medicine, 1947." The Nobel Foundation. Available at <http://www.nobel.se/medicine/laureates/1947/index.html>.