Phoebus Aaron Theodor Levene Biography

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World of Genetics on Phoebus Aaron Theodor Levene

The organic chemist Phoebus Levene isolated and discovered the structure of the individual units of deoxyribonucleic (DNA) and ribonucleic acid (RNA). DNA and RNA consist of an acidic phosphate group, a nitrogenous base, and a sugar. Following Levene's notation, the base and the sugar are called a nucleoside; the addition of the phosphate completes the nucleotide. In the 1910s, Levene identified the sugar in RNA as D-ribose, the biologically active mirror image of commercially available L-ribose. Similarly, in the late 1950s, he identified the sugar in DNA as D-2-deoxyribose (D-ribose minus an oxygen at the 2-position). By 1935, Levene had determined that both sugars were furanose rings. Based on the structure of individual units, Levene proposed that DNA joined together in groups of four. Although his theory would later prove to be incorrect, Levene's tetranucleotide hypothesis long held sway as the model of DNA structure. A series of models for DNA structure were proposed before American geneticist and biophysicist James Watson (1928-) and British biophysicist Francis Crick (1916-) finally determined the correct structure in 1953.

Levene and his family immigrated to the United States in 1891 to escape Russian anti-Semitism.

Levene was born in Sagor, Russia in 1869 and admitted to the Imperial Medical Academy in St. Petersburg in 1886. He briefly returned to St. Petersburg in 1891 to receive his medical degree. Back in New York, he served the medical needs of the Russian Jewish community for several years. Levene gradually became more interested in scientific research and enrolled at Columbia School of Mines and College of Physicians and Surgeons. After a battle with tuberculosis in the early 1900s, he began research on proteins and nucleic acids in earnest. In 1905, Levene gained an appointment at the new Rockefeller Institute of Medicine, where he remained in the division of chemistry for the rest of his professional life. The Rockefeller Institute was a model early-twentieth century research institution and a famous site for excellent discoveries in the biomedical sciences.

At the time that Levene completed his work on the structure of DNA and RNA, certain proteins were still assumed the molecules of inheritance. Because DNA is now known to be the material substance of genes, Levene is largely remembered for these contributions; however, he was a prolific researcher on the biochemical analysis and synthesis of molecules associated with proteins. This research was what originally led him to nucleic acids, because both DNA and RNA are entwined with various proteins throughout the cell cycle.