Phoebus Aaron Theodore Levene,
M.D. (25 February 1869 – 6 September
1940) was an American biochemist who studied the structure and
function of nucleic acids. He characterized the different forms of
DNA from RNA, and found that
DNA contained adenine,
guanine, thymine, cytosine, deoxyribose, and a phosphate
He was born into a Litvak (Lithuanian Jewish) family as Fishel
Rostropovich Levin in the town of
Žagarė in Lithuania, then part of
the Russian Empire, but grew up in St. Petersburg. There he studied
medicine at the Imperial Military Medical Academy (M.D., 1891) and
developed an interest in biochemistry. In 1893, because of
anti-Semitic pogroms, he and his family emigrated to the United States
and he practiced medicine in New York City.
Levene enrolled at
Columbia University and in his spare time conducted
biochemical research, publishing papers on the chemical structure of
sugars. In 1896 he was appointed as an Associate in the Pathological
Institute of the New York State Hospitals, but he had to take time off
to recuperate from tuberculosis. During this period, he worked with
several chemists, including
Albrecht Kossel and Emil Fischer, who were
the experts in proteins.
In 1905, Levene was appointed as head of the biochemical laboratory at
the Rockefeller Institute of Medical Research. He spent the rest of
his career at this institute, and it was there that he identified the
components of DNA. (He had discovered ribose in 1909
and deoxyribose in 1929.) Not only did Levene
identify the components of DNA, he also showed that the components
were linked together in the order phosphate-sugar-base to form units.
He called each of these units a nucleotide, and stated that the DNA
molecule consisted of a string of nucleotide units linked together
through the phosphate groups, which are the 'backbone' of the
molecule. His ideas about the structure of
DNA were wrong; he thought
there were only four nucleotides per molecule. He even declared that
it could not store the genetic code because it was chemically far too
simple. However, his work was a key basis for the later work that
determined the structure of DNA. Levene published over 700 original
papers and articles on biochemical structures. Levene died in 1940,
before the true significance of
DNA became clear.
Levene is known for his "tetranucleotide hypothesis" (formulated
around 1910) which first proposed that
DNA was made up of equal
amounts of adenine, guanine, cytosine, and thymine. Before the later
work of Erwin Chargaff, it was widely thought that
DNA was organized
into repeating "tetranucleotides" in a way that could not carry
genetic information. Instead, the protein component of chromosomes was
thought to be the basis of heredity; most research on the physical
nature of the gene focused on proteins, and particularly enzymes and
viruses, before the 1940s.
^ Kay, Lily E. (1992). The Molecular Vision of Life: Caltech, the
Rockefeller Foundation, and the Rise of the New Biology. Oxford
University Press. pp. 104–116. ISBN 0-19-505812-7.
Tipson RS (1957). "Phoebus Aaron Theodor Levene, 1869–1940". Adv
Carbohydr Chem. 12: 1–12. doi:10.1016/s0096-5332(08)60202-7.
references for the discovery of ribose and deoxyribose:
See P. A. Levene and L. W. Bass, Nucleic Acids, The Chemical Catalog
Co., NY, 1931, pp 24 (deoxyribose) and 131 (ribose). Acids
Levene PA, La Forge FB (April 1915). "On Chondrosamine". Proc. Natl.
Acad. Sci. U.S.A. 1 (4): 190–1. doi:10.1073/pnas.1.4.190.
PMC 1090774 . PMID 16575974.
Simoni RD, Hill RL, Vaughan M (31 May 2002). "The Structure of Nucleic
Acids and Many Other Natural Products: Phoebus Aaron Levene". J. Biol.
Chem. 277 (22): e11. This short article by Simoni, et al.
mentions scientific contributions including the paper: Levene PA
(1919). "The Structure of Yeast Nucleic Acid: IV. Ammonia Hydrolysis"
(PDF). J. Biol. Chem. 40 (2): 415–424.
National Academy of Sciences Biographical Memoir
Discovery of the
DNA Double Helix
Sir John Randall
ISNI: 0000 0001 0965 9133