Word: restrictionism
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The discovery of these so-called restriction enzymes promises to help un ravel the mysteries of cell development, hereditary disease and cancer. It has al ready allowed scientists to analyze the chemical structure of genes and to map their sequence along DNA strands. It has ushered in a new age...
Last week Sweden's Karolinska Institute underlined the importance of restriction enzymes by awarding the Nobel Prize for Medicine, this year worth $165,000, to a trio of pioneers in the field. The three, all microbiologists: Werner Arber, of the University of Basel in Switzerland, and Drs. Hamilton O...
Arber, 49, first postulated the existence of restriction enzymes in the early 1960s while studying viruses that invade bacteria. After labeling a virus with a radioactive isotope that acted as a tracer, Arber found that when the virus entered a bacterium, most of the viral DNA was destroyed. But how...
Arber theorized that the bacterium produced a "restriction" enzyme that cut the viral DNA into smaller pieces (the host bacterium's DNA is protected from its own chemical scissors by other enzymes). Arber further proposed that the enzymes recognized and acted upon specific sites along the DNA strand.
Arber's theories were verified by Smith, 47, a former naval medical officer and member of the U.S. Public Health Service who turned to genetic research. In 1970 Smith published two classic papers that described his discovery of a restriction enzyme produced by the bacterium Hemophilus influenzae and the...