Phoebus Aaron Theodore Levene (25 February 1869 – 6 September 1940) was a Russian born American

biochemist Biochemists are scientists who are trained in biochemistry. They study chemical processes and chemical transformations in living organisms. Biochemists study DNA, proteins and cell parts. The word "biochemist" is a portmanteau of "biological ch ...

who studied the structure and function of

nucleic acid Nucleic acids are biopolymers, macromolecules, essential to all known forms of life. They are composed of nucleotides, which are the monomers made of three components: a 5-carbon sugar, a phosphate group and a nitrogenous base. The two main ...

s. He characterized the different forms of nucleic acid, DNA from RNA, and found that DNA contained

adenine Adenine () ( symbol A or Ade) is a nucleobase (a purine derivative). It is one of the four nucleobases in the nucleic acid of DNA that are represented by the letters G–C–A–T. The three others are guanine, cytosine and thymine. Its deriv ...

guanine Guanine () ( symbol G or Gua) is one of the four main nucleobases found in the nucleic acids DNA and RNA, the others being adenine, cytosine, and thymine ( uracil in RNA). In DNA, guanine is paired with cytosine. The guanine nucleoside is ...

thymine Thymine () ( symbol T or Thy) is one of the four nucleobases in the nucleic acid of DNA that are represented by the letters G–C–A–T. The others are adenine, guanine, and cytosine. Thymine is also known as 5-methyluracil, a pyrimidin ...

cytosine Cytosine () ( symbol C or Cyt) is one of the four nucleobases found in DNA and RNA, along with adenine, guanine, and thymine ( uracil in RNA). It is a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attached ( ...

, deoxyribose, and a phosphate group. He was born into a Litvak (Lithuanian Jewish) family as ''Fishel Rostropovich Levin'' in the town of Žagarė in

Lithuania Lithuania (; lt, Lietuva ), officially the Republic of Lithuania ( lt, Lietuvos Respublika, links=no ), is a country in the Baltic region of Europe. It is one of three Baltic states and lies on the eastern shore of the Baltic Sea. Lithuania ...

, then part of the

Russian Empire The Russian Empire was an empire and the final period of the Russian monarchy from 1721 to 1917, ruling across large parts of Eurasia. It succeeded the Tsardom of Russia following the Treaty of Nystad, which ended the Great Northern War ...

, 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

pogrom A pogrom () is a violent riot incited with the aim of massacring or expelling an ethnic or religious group, particularly Jews. The term entered the English language from Russian to describe 19th- and 20th-century attacks on Jews in the Russian ...

s, he and his family emigrated to the United States and he practiced medicine in

New York City New York, often called New York City or NYC, is the List of United States cities by population, most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the L ...

. Levene enrolled at

Columbia University Columbia University (also known as Columbia, and officially as Columbia University in the City of New York) is a private research university in New York City. Established in 1754 as King's College on the grounds of Trinity Church in Manhatt ...

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 Ludwig Karl Martin Leonhard Albrecht Kossel (; 16 September 1853 – 5 July 1927) was a German biochemist and pioneer in the study of genetics. He was awarded the Nobel Prize for Physiology or Medicine in 1910 for his work in determining the ch ...

and

Emil Fischer Hermann Emil Louis Fischer (; 9 October 1852 – 15 July 1919) was a German chemist and 1902 recipient of the Nobel Prize in Chemistry. He discovered the Fischer esterification. He also developed the Fischer projection, a symbolic way of draw ...

, 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. In 1909, Levene and

Walter Jacobs Marion Walter Jacobs (May 1, 1930 – February 15, 1968), known as Little Walter, was an American blues musician, singer, and songwriter, whose revolutionary approach to the harmonica had a strong impact on succeeding generations, earning him ...

in 1909 recognised -

ribose Ribose is a simple sugar and carbohydrate with molecular formula C5H10O5 and the linear-form composition H−(C=O)−(CHOH)4−H. The naturally-occurring form, , is a component of the ribonucleotides from which RNA is built, and so this com ...

as a

natural product A natural product is a natural compound or substance produced by a living organism—that is, found in nature. In the broadest sense, natural products include any substance produced by life. Natural products can also be prepared by chemical sy ...

and an essential component of

s. They also recognised that the unnatural sugar that

and Oscar Piloty had reported in 1891 was the

enantiomer In chemistry, an enantiomer ( /ɪˈnænti.əmər, ɛ-, -oʊ-/ ''ih-NAN-tee-ə-mər''; from Ancient Greek ἐνάντιος ''(enántios)'' 'opposite', and μέρος ''(méros)'' 'part') – also called optical isomer, antipode, or optical anti ...

of -ribose. Levene went on to discover 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 Nucleotides are organic molecules consisting of a nucleoside and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecu ...

, 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 which proposed that DNA was made up of ''equal'' amounts of adenine, guanine, cytosine, and thymine. Before the later work of

Erwin Chargaff Erwin Chargaff (11 August 1905 – 20 June 2002) was an Austro-Hungarian-born American biochemist, writer, Bucovinian Jew who emigrated to the United States during the Nazi era, and professor of biochemistry at Columbia University medical scho ...

, 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

chromosome A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins ar ...

s was thought to be the basis of heredity; most research on the physical nature of the

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...

focused on

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...

s, and particularly

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...

s and

virus A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsk ...

es, before the 1940s.

Citations

General and cited references

* References for the discovery of ribose and deoxyribose: * P. A. Levene and L. W. Bass, ''Nucleic Acids'', The Chemical Catalog Co., NY, 1931, pp 24 (deoxyribose) and 131 (ribose).

External links

* * This short article by Simoni, ''et al.'' mentions scientific contributions including the paper:
National Academy of Sciences Biographical Memoir
{{DEFAULTSORT:Levene, Phoebus 1869 births 1940 deaths American biochemists American people of Lithuanian-Jewish descent American people of Russian-Jewish descent Columbia University alumni Emigrants from the Russian Empire to the United States History of genetics Jewish American scientists Lithuanian Jews Russian Jews Russian people of Lithuanian descent