Ernst Chain

Ernst Chain the German-born biochemist and pathologist (1906-1979) who shared the 1945 Nobel Prize in Physiology or Medicine with Alexander Fleming and Howard Florey for the discovery of penicillin and its curative effect in various infectious diseases. His work on the purification and large-scale production of the antibiotic transformed medicine and opened the antibiotic era.

Early Life and Education

Ernst Boris Chain was born on 19 June 1906 in Berlin, the son of a Russian-born chemist and an Austrian mother. He studied chemistry and biochemistry at the Friedrich Wilhelm University in Berlin, graduating in 1930 with a doctorate on the chemistry of enzymes. Of Jewish descent, he recognised the danger that the rise of the Nazi party posed to his future.

In 1933, soon after Adolf Hitler came to power, Chain left Germany and settled in Britain. He worked briefly at University College Hospital in London and then at the University of Cambridge, where he studied under Frederick Gowland Hopkins, a pioneer of biochemistry. In 1935 he joined the Sir William Dunn School of Pathology at Oxford as a research fellow, where he turned his attention to natural antibacterial substances. He later recalled that the decision to leave Germany was made easier by his conviction that his scientific career could not survive under the new regime.

Penicillin and the Oxford Team

In 1938 Chain read Fleming's 1929 paper describing a mould that inhibited bacterial growth and became convinced that the substance, penicillin, deserved serious chemical study. He joined forces with Howard Florey, the head of the Dunn School, who provided the facilities and pursued the medical potential of the discovery. Together with a team that included Norman Heatley, they undertook the difficult task of isolating the unstable compound. Chain brought to the collaboration a biochemist's understanding of enzymes and of the fragility of the molecule, and he insisted that the substance could be purified and stabilised despite early failures.

By 1940 the Oxford group had produced enough purified penicillin to test it in mice, and the results were dramatic: animals infected with virulent streptococci recovered. In 1941 they treated the first human patient, a policeman dying of infection, who improved before supplies ran out. To obtain sufficient material, the team resorted to growing the mould in bedpans, milk churns and any available vessel, and reused the penicillin recovered from patients' urine. Heatley devised an assay method and a back-extraction technique that made it possible to recover the drug from solution on a practical scale.

Wartime Production and the Nobel Prize

The scale of the need far exceeded the capacity of a university laboratory, and with Britain at war the Oxford team turned to American industry. Florey and Heatley travelled to the United States in 1941 to enlist pharmaceutical companies, and improved deep-tank fermentation methods soon raised yields enormously. By 1944 there was enough penicillin to supply the Allied armies, saving countless lives among wounded soldiers. The strain of mould that gave the highest yields was found on a mouldy cantaloupe in a Peoria market, and its descendants supplied the world's penicillin for decades.

In 1945 Chain, Florey and Fleming were jointly awarded the Nobel Prize in Physiology or Medicine for the discovery of penicillin and its therapeutic value. Chain's particular contribution was the isolation, purification and determination of the chemical nature of the substance, work that made its clinical use possible. The prize recognised one of the most consequential medical advances of the twentieth century. Chain had also shown that penicillin acted by interfering with the formation of the bacterial cell wall, a mechanism that remains the basis of its selective toxicity.

Later Career and Scientific Interests

After the war Chain held posts in Italy, where he directed a research institute in Rome, and in Britain, where he became professor of biochemistry at Imperial College London in 1961. He continued to work on antibiotics, on the mechanism of insulin action, and on fermentation technology, and he helped establish a centre for biochemical research in the Soviet Union.

Chain was a man of wide culture who spoke several languages and took a strong interest in the philosophy and sociology of science. He was alert to the dangers of antibiotic resistance and argued for the prudent use of the new drugs. He also reflected publicly on the social responsibility of scientists and on the conditions that allow discovery to flourish. In his later writings he stressed that the great advances of medicine depended on a union of pure research with clinical practice.

Influence and Legacy

The introduction of penicillin changed the practice of medicine more radically than almost any discovery of the century. Infections that had routinely killed, from infected wounds to puerperal fever and pneumonia, became treatable, and surgery could be undertaken with far greater safety. The antibiotic era that Chain helped to begin reshaped public health, agriculture and the pharmaceutical industry.

Chain received many honours, including fellowship of the Royal Society, and his name is bound to the story of penicillin alongside those of Fleming and Florey. Historians of science regard the Oxford programme as a model of how basic biochemistry can be translated into a remedy of worldwide benefit. His career also illustrates the migration of talent that the upheavals of the 1930s forced upon European science.

See also

• Penicillin
• Howard Florey
• Antibiotic resistance
• Nobel Prize in Physiology or Medicine