Dorothy Crowfoot Hodgkin

British biochemist

• Born: May 12, 1910
• Birthplace: Cairo, Egypt
• Died: July 29, 1994
• Place of death: Shipston-on-Stour, Warwickshire, England

Hodgkin is best known for determining the structures of such biologically important molecules as penicillin, vitamin B¹² and insulin. She also was a founding member and president of Pugwash, an organization devoted to the eradication of weapons of mass destruction and the peaceful application of scientific knowledge.

Early Life

Dorothy Crowfoot Hodgkin was born in Cairo, Egypt, where her father, John Crowfoot, was a school supervisor for the British government. Her mother, Grace Mary “Molly” Hood, was a self-taught botanist and artist who became an expert in Coptic textiles. During the years before World War I, Dorothy and her two younger sisters spent their summers in England, but when the war broke out in August of 1914, they and their nursemaid spent the war isolated from their parents, who could not leave Egypt. They arranged for their children to stay with John’s parents, who had retired to Worthing on the south coast of England. Dorothy attended a local school and became fascinated with collecting flints in the local countryside. Molly arrived in Worthing shortly before the armistice, but Dorothy had been devastated by the loss of four of her brothers; Molly did arrive with a new sister for Dorothy. Dorothy later said that these early experiences taught her self-reliance and a hatred of war.

John Crowfoot, who had become director of education in the Sudan, recognized that he was nearing the end of his government service, and he decided to establish a permanent home for his family near Beccles in Suffolk, close to England’s east coast, where his father had grown up. In 1921, Dorothy began attending Leman School. Her chemistry teacher was a woman who encouraged her talented pupil’s love for the subject. In 1923, during a trip to the Sudan to visit her father, Dorothy discovered, in panning for gold, a lustrous black crystal of ilmenite, which, with the help of a soilchemist, she found contained iron and titanium. This was her introduction to the joys of scientific research. For her sixteenth birthday Molly gave her a book by William Henry Bragg, in which he explains how X rays could be used to discover a crystal’s atomic arrangement, and, thus, Dorothy was inaugurated into what would become her lifelong vocation.

After her secondary school graduation in 1927, Dorothy needed to master Latin and other subjects to pass the entrance examination for Oxford University. Consequently, she did not enter Somerville College at Oxford until October of 1928. She was able to deepen her knowledge of chemistry through courses taught by such distinguished professors as Robert Robinson, but she learned most through her laboratory research. To fulfill the honors requirement for her B.A., she chose as her senior-year original-research project an X-ray study of thallium dialkyl halide crystals, in which she discovered that the chloride, bromide, and iodide compounds had a structure similar to the cubic arrangement of atoms in common salt. With her project director, Herbert Powell, she published her results in Nature, Britain’s leading scientific journal. Although she graduated with honors in 1932, she experienced difficulties in finding a postgraduate position until she learned that John Desmond Bernal at Cambridge University believed in equal opportunities for women.

Life’s Work

Bernal was an unconventional professor, not only as a pioneering X-ray crystallographer but also as an advocate for socialism and free love. He was one of the first to use X rays to study crystals of biological materials such as calciferol (vitamin D). Hodgkin formed a productive collaboration with Bernal, and she coauthored twelve published papers with him in the 1930’s. Particularly important was their X-ray photograph of the digestive enzyme pepsin it was the first time that a protein crystal had yielded a diffraction picture. This proved to be the start of the important field of macromolecular crystallography.

Like Bernal and many others, Hodgkin was alarmed by the rise of Nazism in Germany, and she joined such left-wing organizations as the Association of Scientific Workers. Although she had an affair with Bernal, she realized that a fully committed relationship was not possible, since he had a wife and two children, supported households of two other women, and had numerous other liaisons.

In 1934, Hodgkin returned to Somerville College, where she devoted herself to teaching and laboratory research. She also learned that she was suffering from rheumatoid arthritis, which she suffered from during the rest of her life. Despite her pain and her exclusion from the faculty chemistry club (because she was a woman), she was able to do excellent work. For example, she crystallized and took X-ray photographs of insulin, the hormone that controls blood sugar. This large molecule, with a molecular weight of about 37, 200, provided structural mysteries that would take her thirty-four years to unravel.

During the spring of 1937, Hodgkin went to the Royal Institution in London to use its powerful X-ray equipment to get detailed photographs of insulin. While there she met Thomas Hodgkin, a historian who had been educated at Oxford. After she returned to Oxford, she and Thomas began a correspondence, which led to his courting of her. Meanwhile, she completed her doctoral thesis on the chemistry and crystallography of certain sterols, and Cambridge awarded her a Ph.D. in 1937. At the end of this year, Thomas Hodgkin and Dorothy Crowfoot were married; they had three children: Luke, born in 1938, Elizabeth, born in 1941, and Toby, born in 1946. Unfortunately, the couple’s jobs kept them separated during the early years of their marriage, but they often got together on weekends.

Hodgkin continued her work on such proteins as insulin, lactoglobulin, and lysozyme during the late 1930’s and throughout the war years. She also completed her studies of cholesterol iodide, and her elucidation of its structure in the early 1940’s marked a breakthrough in molecular biology. She became the first scientist to establish the stereochemical arrangement of each carbon atom in a steroid molecule. She then learned about penicillin and its antibiotic properties. Realizing that it would play an important role in treating wounded soldiers, she decided to figure out its three-dimensional structure to facilitate its mass production. With Rockefeller Foundation grants and an early International Business Machines (IBM) analog computer, she was able to delineate penicillin’s unusual ring structure.

After the war she published her results on the ring structure of penicillin, was elected to the Royal Society, and began work on the structure of vitamin B¹²¹². This molecule was much larger than penicillin, and it took Hodgkin six years to work out the details of its atomic arrangement. She and her group used more than twenty-five hundred X-ray photographs and a powerful new electronic computer to solve this vitamin’s structural mysteries. When their results were published in 1956, one scientist called it the most significant achievement yet attained in natural-products chemistry. This accomplishment led, in 1964, to Hodgkin being awarded the Nobel Prize in Chemistry.

By this time she had become Wolfson Research Professor of the Royal Society, and she made use of her improved funding to finally solve the puzzles of insulin’s 777 atoms. It took most of the 1960’s and the combined efforts of her colleagues and students to work out the details of this important substance. When she published the results in 1969, she considered it one of her greatest scientific achievements.

During the 1960’s and following decades, she received many awards. In 1965 the queen of England bestowed on her the Order of Merit, and she thus became the first woman since Florence Nightingale to be given Britain’s most prestigious honor. She was also able to use the illustriousness of her awards to gain a larger audience for her views on international peace. She was president of Pugwash, an international group of scientists concerned with nuclear disarmament and peaceful uses of scientific knowledge, from 1975 to 1988. Through her role as Pugwash president and her participation with other international organizations, as well as through her travels in Africa, China, India, and the United States, she tried to bring about reconciliation among the conflicting peoples of the world. She also influenced one of her former chemistry students, Margaret Thatcher, who had become the British prime minister, to visit the Soviet Union, which led to an improved rapport between England and the Soviet Union of Mikhail Gorbachev.

After her husband, a heavy smoker, died of emphysema in 1982, Hodgkin experienced deep grief. Her own health began to fail, and she relinquished the remaining responsibilities of her scientific and peace work. She died of a stroke on July 29, 1994, at her home northwest of Oxford, surrounded by members of her family.

Significance

Hodgkin was one of the most important X-ray crystallographers in the history of this discipline. She not only mastered traditional techniques but also helped develop powerful new methods. She used this mastery of X-ray analysis to discover the structures of such biologically and medically critical molecules as penicillin, vitamin B¹², and insulin.

Hodgkin’s influence extended into the future through her more than one hundred students, over three-quarters of whom came from foreign countries, with a large percentage being women. Her deep internationalism and humanism were obvious in her participation in various peace organizations, in which she emphasized person-to-person communication rather than political ideologies. In her multifarious activities she tried to bring the world a little closer to the gentleness and kindness that informed her own character.

Bibliography

Dodson, Guy. “Dorothy Mary Hodgkin, OM.” Biographical Memoirs of Fellows of the Royal Society 48 (2002): 179-219. Hodgkin wrote J. D. Bernal’s Royal Society biographical memoir in 1980, and Dodson, who worked with Hodgkin on the insulin determination, provides a good survey of Hodgkin’s life and work, along with a bibliography of her principal publications.

Dodson, Guy, Jenny Glusker, Sivaraj Ramaseshan, and K. Venkatesan, eds. The Collected Works of Dorothy Crowfoot Hodgkin. Vols. 1-3. Bangalore, Pakistan: Interline, 1994. This series includes both published and previously unpublished writings. Particularly interesting is Hodgkin’s unfinished autobiography.

“Dorothy Crowfoot Hodgkin: In Memoriam.” Current Science 72 (1997): 447-493. Special section devoted to Hodgkin. In addition to Jack Dunitz’s introduction to her work and personality, this commemorative section contains reminiscences of such friends and colleagues as Max Perutz, David Phillips, Guy Dodson, and others.

Ferry, Georgina. Dorothy Hodgkin: A Life. Cold Spring Harbor, N.Y.: Cold Spring Harbor Laboratory Press, 1998. This first book-length biography of Hodgkin is based on private papers and interviews with family, friends, and colleagues. Intended for general readers, it has a select bibliography, notes to primary and secondary sources, and an index.

McGrayne, Sharon Bertsch. Nobel Prize Women in Science: Their Lives, Struggles, and Momentous Discoveries. 2d ed. Washington, D.C.: Joseph Henry Press, 1998. The chapter on Hodgkin is based on interviews with Hodgkin and with several of her colleagues, as well as on published sources, all of which are given in the “notes” section. A good introduction to Hodgkin’s life and work. Index.