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This section contains 844 words (approx. 3 pages at 300 words per page) |
World of Genetics on Daniel Nathans
Daniel Nathans is best known for his work with restriction enzymes, which are used to cut or break DNA (deoxyribonucleic acid) molecules. This technique, first applied to gene study by Nathans, led the way in studying the structure of viruses and opened the door for recombinant DNA research and genetic mapping. His work was recognized in 1978, when he shared the Nobel Prize in physiology or medicine with Werner Arber and Hamilton O. Smith.
Nathans was born in Wilmington, Delaware, the last of nine children born to Samuel and Sarah Nathans, Russian Jewish immigrants. Nathans received his B.A. from the University of Delaware in 1950 and his M.D. from Washington University in St. Louis in 1954. It was during the summer after his first year of medical school that Nathans had his initial exposure to laboratory work.
After medical school, Nathans completed a one-year internship at Columbia-Presbyterian Medical Center. After this, he spent two years (1955-57) at the National Cancer Institute as a clinical associate studying protein synthesis. In 1956, Nathans married Joanne Gomberg, with whom he had three sons. Returning to Columbia-Presbyterian, Nathans completed his residency in 1959. That same year Nathans won a United States Public Health Service grant to do biochemical research at Rockefeller University in New York with Fritz Lipmann and Norton Zinder. It was at this point that Nathans fully committed to work in the laboratory rather than in a clinical practice. In New York, Nathans continued his work on protein synthesis and began viral research, mostly related to host-controlled variations in viruses.
In 1962, Nathans began his long relationship with Johns Hopkins University as assistant professor of microbiology and director of genetics. He was elevated to associate professor in 1965 and full professor in 1967. He was named director of the molecular biology and genetics department in 1972 and Boury Professor of Molecular Biology and Genetics in 1976, positions he retained for many years.
In 1962, when Nathans first arrived at Johns Hopkins, Werner Arber, at Basel University in Switzerland, predicted the existence of an enzyme capable of cutting DNA at specific sites. Deoxyribonucleic acid (DNA) is assumed to be the source of autoreproduction in many viruses. An ability to cut or cleave the DNA into specific and predictable fragments was important to greatly improving our capabilities for researching and understanding viruses. The necessity of specific and predictable fragments relates to the need of the scientist to know the fragment he or she is studying is identical to the fragment any other scientist would get following the same laboratory procedure.
In 1968, Arber was halfway to his goal, finding an enzyme (type I) capable of cleaving DNA, but in seemingly random patterns. In 1969, Hamilton O. Smith, a colleague of Nathans at Johns Hopkins, wrote to Nathans (who was in Israel at the time) to tell him he had developed a type II enzyme. This enzyme, named Hind II, was capable of cleaving DNA into specific and predictable fragments.
At this time, Nathans was working on a simian virus (SV40) which causes tumors in monkeys. SV40 was particularly impervious to then-current methods of study, so Nathans immediately saw an application of Smith's tool. Nathans, with Kathleen Danna, used Hind II to cut SV40 into eleven pieces and show its method of replication.
The combined efforts of Arber, Smith, and Nathans over a period of more than a decade led to their receipt of the Nobel Prize in physiology or medicine in 1978. Their inter-laboratory cooperation greatly advanced the potential for consistent DNA and gene research.
Nathans continued his work with Hind II and cleared the path for much of the work that has been done since in research on DNA function and structure (such as restrictions maps, used to define DNA structure). This early work has also led to the area of recombinant DNA research, which involves the process of joining two DNA fragments from separate sources into one molecule. Since this field of research was uncharted territory and carried some risks, including the creation of new pathogens, Nathans was among an early group of scientists who, in 1974, encouraged the publication of research guidelines and some self-imposed limits on DNA research. Despite the risks, recombinant DNA research has been put to good use in creating supplies of heretofore scarce enzymes and hormones, including insulin.
In the 1980s, Nathans's research continued to be linked closely to DNA and genetics. A good portion of his scientific work during this time related to the effect of growth factors on genes and gene regulation. Nathans was a member of the American Academy of Arts and Sciences. He was a senior investigator at the Howard Hughes Medical Institute and a member of the National Academy of Sciences. He has served on the editorial board of Proceedings of the National Academy of Sciences and has been a regular contributor. He maintained his association with the National Cancer Institute and authored dozens of articles for several scientific journals. Nathans, a major player in scientific research and education in the mid to late part of the twentieth century, died in Baltimore at age 71..
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This section contains 844 words (approx. 3 pages at 300 words per page) |
