Dr. Howard M. Temin, a cancer researcher who won the Nobel Prize for his role in discovering an enzyme that overturned a central tenet of molecular biology, died of lung cancer Wednesday at his home in Madison, Wis. He was 59.
The enzyme, reverse transcriptase, later played a crucial role in identifying the AIDS virus. It also became the underpinning of much of the biotechnology industry and was crucial to the genetic engineering that has produced drugs such as human insulin and tpa, a clot-busting agent that stops heart attacks in progress.
Dr. Temin, who crusaded against cigarettes, never smoked. His lung cancer, adenocarcinoma, was a type that is not linked to smoking, said officials of the University of Wisconsin, where he worked for 34 years.
A soft-spoken man who kept trim by walking long distances and bicycling, Dr. Temin did not hesitate to speak out, including about smoking.
When he received his Nobel in Stockholm in 1975 from King Carl XVI Gustaf of Sweden, Dr. Temin bowed to the king, then scolded members of the audience at the ceremony for smoking while he was being honored for his efforts to combat cancer.
He shared the prize with his former professor, Dr. Renato Dulbecco, and another researcher, Dr. David Baltimore.
Dr. Temin's award was for his role in discovering reverse transcriptase, the enzyme that helps certain viruses subvert the genetic machinery of the cells they infect. He found the enzyme in a virus that causes cancer in chickens. Dr. Baltimore independently discovered reverse transcriptase in a virus that causes cancer in mice.
Dr. Temin's award came after a lonely battle to overcome derisive criticism from scientific leaders who refused to believe in his theory that some viruses carry their genetic information in the form of RNA, which is then copied into DNA in infected cells.
"The idea that RNA could make DNA was considered ludicrous," Dr. Robin Weiss, a leading virologist in London, said in an interview.
For six years, Dr. Temin persisted against the criticism until he identified the enzyme, reverse transcriptase, that proved the theory.
Dr. J. Michael Bishop, who won a Nobel Prize in 1989, said that Dr. Temin had "an exceptional, independent intellect and imagination that produces discoveries, and he produced them."
In an interview yesterday, Dr. Bishop recalled entering the field and watching "Howard go from a figure thought by some to be irresponsible and lax in interpreting data to be a lion overnight. It was quite a lesson for me in intellectual courage because he just toughed it."
Howard Martin Temin was born in Philadelphia in 1934. His father was a lawyer and his mother was active in educational affairs.
said that his interest in biological research was spurred by participating in a summer program for high school students at the Jackson Laboratory in Bar Harbor, Maine, and a summer at the Institute for Cancer Research in Philadelphia.
He published his first scientific paper at age 18, and when he graduated from Swarthmore College, his yearbook described him as "one of the future giants in experimental biology."
In 1960, Temin moved to the University of Wisconsin. Working in the basement near a sump and under steam pipes, he began the experiments that led to the Nobel Prize.
He is survived by his wife, Rayla Greenberg Temin, a medical geneticist at the University of Wisconsin; two daughters, Sarah Temin of Berkeley, Calif., and Miriam Temin of San Francisco; and two brothers, Michael Temin of Philadelphia and Peter Temin of Cambridge, Mass.