Hugo Theorell

Swedish biochemist

• Born: July 6, 1903
• Birthplace: Linköping, Sweden
• Died: August 15, 1982
• Place of death: Stockholm, Sweden

Theorell received the 1955 Nobel Prize in Physiology or Medicine for his work on the nature and action of oxidation enzymes. He was the first to produce a pure enzyme in the laboratory and the first to produce myoglobin in a pure form. His discoveries found wide scientific application in the study of cancer and tuberculosis, among other diseases.

Early Life

Hugo Theorell (teh-oo-REHL) was born in Linköping, Sweden, the son of the local military regiment’s medical officer. Little has been written of the younger Theorell’s early life. Like his father, he chose medicine as his vocation. He entered the Caroline Institute in Stockholm in 1921 and studied under Walther Hermann Nernst, who had won the Nobel Prize in 1920. Theorell was awarded his bachelor of medicine degree in 1924. He also studied at the Pasteur Institute in Paris.

Most of his academic work consisted of research into the chemistry of plasma lipids and their influence on red blood cells. He did this research under the direction of Einar Hammarstein at the Royal Caroline Medico-Surgical Institute. He was awarded his doctor of medicine degree by the Caroline Institute in 1930 and was preparing to embark on the career of medical practitioner when an attack of poliomyelitis left him disabled in both legs. Undaunted by this unfortunate turn of events, Theorell took up research and teaching.

Theorell was a short, stocky man, modest and reticent; for relaxation he enjoyed sailing. In 1931, he married a music teacher, Margit Alenius, who later became a professional musician. Theorell was himself a violinist and he appeared with the Academic Orchestra Society. He chaired the Stockholm Philharmonic Society. The Theorells had three sons.

Life’s Work

After receiving his doctorate, Theorell was appointed docent at the Caroline Institute. Using a new ultracentrifuge at the Svedberg in Uppsala, he investigated the molecular weight of myoglobin, an iron-containing protein of muscle tissue that has oxygen-carrying functions related to those of hemoglobin in the blood. Myoglobin is the pigment that makes muscles red. Theorell was an assistant professor of chemistry at Uppsala from 1932 to 1933 and from 1935 to 1936, taking leave to work in Berlin and Stockholm.

In 1933, Theorell was given a Rockefeller Fellowship to work at the Kaiser Wilhelm Institute in Berlin with Nobel Prize winner (1931) Otto Warburg. There, using electrophoretic methods that he had worked out himself, he purified a yellow enzyme, a feat Warburg had been attempting for years without success. Other enzymes had been isolated and crystallized by American Nobel Prize winner James Sumner, but the yellow enzyme, found in yeast, heart muscle, and milk, had remained problematic.

By dialysis of an acidified solution, Theorell separated the yellow enzyme into two fragments: the nonprotein coenzyme, which acts as a catalyst, and the apoenzyme, a colorless, pure protein, and determined that the yellow enzyme’s essential ingredient is albumin. The coenzyme, a substance of low molecular weight, was identified as a monophosphate of vitamin B₂. The substance is now known as flavin mononucleotide and is believed responsible for the yellow coloration of the enzyme. The coenzyme and apoenzyme must exist together for enzyme activity to occur. In fact, Theorell found that the separation process was reversible. He also discovered the chemical chain reaction by which enzymes enable living cells to breathe (oxidation).

From 1937 to 1970, Theorell was head of the biochemistry department of the Nobel Institute. The department had been established in 1936 by the Caroline Institute in Stockholm to give Theorell an opportunity to continue his research. Under his direction, the department became world-renowned as a “Mecca of biochemistry.”

On returning from Berlin, Theorell began his research on the cytochrome C molecule, a heme-containing protein associated with cellular respiration. By 1936, he had been able to produce an 80 percent pure molecule, and by 1939 he succeeded in purifying cytochrome C 100 percent. His sometime associate and colleague Linus Pauling had discovered the “Alpha” spiral, or twisted atom chains of protein molecules. Theorell’s work confirmed Pauling’s findings. With Anders Ehrenberg, he constructed models of hemin peptides and was able to determine the precise nature of the chemical linkage between the iron-bearing, nonprotein porphyrin portion and the apoenzyme.

At the biochemistry department of the Nobel Institute, he directed studies of ADH enzymes, which break down alcohol in the kidneys. From this research, he was able to develop a new method of determining ethyl alcohol content in the bloodstream. These techniques were later adopted by the Swedish and West German governments for use in tests for drunkenness. Theorell’s research resulted in the isolation of bacteria strains that were used in the treatment of tuberculosis. He also discovered an antibiotic called proaptin.

Articles by Theorell have appeared in many scientific journals, including Biochemische Zeitschrift, Arkiv för Kemi, Journal of the American Chemical Society, Bulletin de la Société de Chimie Biologique, Acta Chemica Scandinavica, and Rendiconti Istituto di Sanità Publíca.

Theorell was active in many professional organizations. He was secretary of the Swedish Society of Physicians and Surgeons from 1940 to 1946 and of the Swedish Society for Medical Research from 1942 to 1950, and he chaired the Swedish Chemists’ Association from 1947 to 1949. He was a member of the Swedish Royal Academy of Sciences, the Scientific Council of the Swedish Board of Health, and the Swedish Academy of Engineering Science. He was a foreign associate of the United States National Academy of Sciences and a foreign member of Great Britain’s Royal Society. He received honorary degrees from Belgium, Brazil, the United States, and France, including an honorary doctor’s degree from the Sorbonne. Theorell died on August 15, 1982.

Significance

Theorell’s work helped create a modern understanding of enzyme action. His research shed light on the basic unit of life, the cell. Much of this work laid the groundwork for the creation of artificial life in the laboratory. Furthermore, his discoveries found wide scientific application in the study of cancer and tuberculosis, among other diseases.

Bibliography

Aaseng, Nathan. The Disease Fighters: The Nobel Prize in Medicine. Minneapolis, Minn.: Lerner, 1987. In this brief book, Aaseng details the discoveries of several Nobel Prize-winning scientists. Written for high school or younger readers.

Candee, Marjorie Dent, ed. Current Biography Yearbook, 1956. New York: H. W. Wilson, 1957. Published annually, this book provides biographies of people in the news. Written in clear language for general readers.

Ludovici, Laurence James, ed. Nobel Prize Winners. Westport, Conn.: Associated Booksellers, 1957. This book details the lives of fourteen well-known Nobel Prize winners, including many contemporaries of Theorell. Gives the student a perspective on the golden age of science of the late nineteenth and early twentieth centuries. For high school students and older.

Raju, Tonse N. K. The Nobel Chronicles: A Handbook of Nobel Prizes in Physiology or Medicine, 1901-2000. Bloomington, Ind.: First Books Library, 2002. A collection of Raju’s articles about Theorell and other Nobel Prize-winners that originally appeared in Lancet, a British medical journal. The article about Theorell was published in Lancet 353 (May 22, 1999): 1807.

Schück, H., et al. Nobel: The Man and His Prizes. 2d rev. ed. New York: Elsevier, 1962. A comprehensive account of the five major Nobel Prizes. Contains the life of Alfred Nobel as well as the rationale behind the establishment of the Nobel Foundation. A page-long description of the prize-winning work by Theorell on enzymes is included. College-level material. Index.

Schwert, George W., and Alfred D. Winer, eds. The Mechanism and Action of Dehydrogenases: A Symposium in Honor of Hugo Theorell. Lexington: University Press of Kentucky, 1970. Papers read at a conference held March 16-19, 1965, at the University of Kentucky. The foreword is by Theorell, who was visiting centennial professor in the biological sciences at the time. College-level material. Bibliographies.

Sourkes, Theodore L. Nobel Prize Winners in Medicine and Physiology, 1901-1965. New York: Abelard-Schuman, 1966. A compilation of short biographies of Nobel Prize winners in medicine and physiology and detailed descriptions of the scientific work that won for them the prize. Much of the section on Theorell is directly quoted from the scientist. For advanced readers.