Pioneers in DNA research honored by colleagues 2 Hopkins Nobelists sparked a revolution

May 30, 1998|By Douglas M. Birch | Douglas M. Birch,SUN STAFF

Two quiet revolutionaries were honored yesterday at the Johns Hopkins School of Medicine nearly 30 years after their discovery of the first tools for taking apart and rewiring DNA, the molecule that controls cellular life.

Daniel Nathans and Hamilton O. Smith helped spark the genetic revolution in the late 1960s and early 1970s, after Smith discovered a chemical, called a restriction enzyme, that cuts DNA at specific points.

Their work made it practical, for the first time, to describe the precise structure of a sizable length of DNA, to pinpoint genes and to swap one gene for another. That eventually led to such advances as genetically engineered drugs, DNA fingerprinting and the worldwide effort to draft a complete blueprint of human DNA.

Nathans, Smith and Swiss scientist Werner Arber won the 1978 Nobel Prize in medicine for their restriction enzyme work. Yesterday in a traditional academic salute, colleagues of the two Hopkins scientists staged a symposium, "The Era of Genetic Discovery."

"They really transformed biology and changed the way we approach human disease," said Thomas J. Kelly, a professor of molecular biology and genetics at Hopkins and one of Smith's former students.

'Marvelous scientists'

"Everything that's going on in modern molecular biology" stems from this work, said Dr. Joan A. Steitz, professor of molecular biophysics at Yale University. "Most of our modern insights into organisms come from these two marvelous scientists."

About 300 people, including three other Nobel Prize winners, showed up for the daylong festivities honoring the two low-key, private men yesterday.

Nathans, 69, a compact man with the demeanor of a judge, sat smiling in the front row of an auditorium. Next to him sat the 6-foot-5 Smith, who laughed at an occasional joke by the speakers but raised his hand shyly to his face when the praise turned personal.

'Down-to-earth guys'

"They're two really down-to-earth Baltimore guys who all of us admire for their modesty, for their integrity and for their decency," said Dr. Joseph L. Goldstein of the University of Texas, who shared the 1985 Nobel in medicine for his work on how the body regulates cholesterol.

Nathans and Smith, both trained as physicians, are the only Nobel winners on Hopkins' faculty. Nathans, who was interim president from 1995 to 1996, holds the title of university professor.

Smith, a professor of molecular biology, is retiring from Hopkins and plans to start working full time July 1 at the Institute of Genomic Research in Rockville.

Smith found the first usable restriction enzyme in 1968, a discovery that he said he "lucked into." Later, he and Kelly determined the precise point where the enzyme would cut DNA. Smith published two papers describing the work in 1970.

Genetic sequence

Scientists have discovered more than 3,000 restriction enzymes, and about 500 of those are routinely used in laboratories to manipulate genetic material. They form the basis for a $300 million-a-year industry, although Smith and Nathans don't get any royalties. Their work was not patented.

Nathans went on to use Smith's enzyme to slice and splice genes and pioneered efforts to read the complete genetic sequence of an organism. He was the first scientist to use a technique called gel electrophoresis to analyze fragments of DNA. Today, the process is routinely used to probe DNA.

"It became clear within a year or two after the publication of our work in 1970 that there was going to be a sizable impact," said Smith. "You began to see how the enzymes could bring an entirely new approach to genetics."

"It led to a great deal of fundamental insights in biology," Nathans said. "And it's still going strong."

During a break in the string of lectures yesterday, Nathans stood surrounded by admiring colleagues.

"It's a wonderful feeling," he said. "A lot of friends are here."

Pub Date: 5/30/98

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