Konrad Bloch—Nobel Prize for Research on Cholesterol

Abstract

German-born American biochemist Konrad Emil Bloch shared the 1964 Nobel Prize for medicine or physiology with German biochemist Feodor Lynen (1911-1979), awarded “for their contributions to understanding the mechanisms and regulation of cholesterol and fatty acid metabolism.” Bloch's research on the biosynthesis of cholesterol advanced the understanding of cholesterol synthesis in living organisms. His studies of the biosynthesis of glutathione (a tripeptide important in protein metabolism) and the metabolism of fatty acids are also notable. Bloch was born on Jan. 12, 1912, in Neisse, Germany (now Nysa in southern Poland). He received his elementary education in Neisse and his secondary education at the Realgymnasium there. He enrolled in the Technische Hochschule in Munich (Germany) in 1930 and received a degree in chemical engineering in 1934. After Bloch received his baccalaureate degree, he emigrated to Switzerland to escape the anti-Semitic environment that followed the rise of Adolf Hitler (1889-1945) in Germany. He found work at the Swiss Research Institute in Davos (eastern Switzerland) and studied the biochemistry of phospholipids in tubercle bacilli. He remained in Switzerland until 1936, when he moved to the United States to enroll at Columbia University in New York City. In 1938, Bloch received his Ph.D. degree from Columbia University. He joined a research group at the Columbia University College of Physicians and Surgeons, where he worked with biochemist Rudolf Schonheimer (1898–1941) and acquired experience in the use of radioisotopes and the isotopic analysis of cell metabolism. While at Columbia, Bloch began to use isotopic techniques to investigate how cholesterol is synthesized in living tissue. In 1942, Bioch and David Rittenberg (1906–1970) discovered that the two–carbon compound acetic acid is the major building block in the 30 or more steps in the biosynthesis of cholesterol. In determining how acetic acid molecules combine in this process, Bloch and Rittenberg collaborated with Lynen and his colleagues in Munich and with John W. Cornforth (1917-) and George Popjak(1914–) in England. Their discoveries facilitated research on the relationship of blood cholesterol levels to atherosclerosis. Their work was also important to research on the chemistry of terpenes, rubber, and other isoprene derivatives. Bloch became a naturalized American citizen in 1944 and joined the faculty of the University of Chicago as a professor of biochemistry in 1946. In 1953, he left Chicago for a 1-year Guggenheim fellowship at the Institute of Organic Chemistry in Zurich, Switzerland. He returned to the United States in 1954 and was appointed Higgins Professor of Biochemistry in the Department of Chemistry at Harvard University (Cambridge, Massachusetts), where he continued his research on lipids, especially the unsaturated fatty acid components. He retired from his academic work in 1978. Bloch was honored on a stamp issued by the Maldive Islands in 1995.