NEW YORK — Osamu Shimomura, who shared the Nobel Prize in chemistry in 2008 for his discovery of a glowing jellyfish protein that is now ubiquitous in biomedical research, died on Friday in Nagasaki, Japan. He was 90.
His death was announced by Nagasaki University, his alma mater.
“Osamu was a quiet and brilliant researcher,” Martin L. Chalfie, a professor of biological sciences at Columbia University who shared the Nobel with Dr. Shimomura and Roger Y. Tsien of the University of California San Diego, said by e-mail. “What always struck me about Osamu was his intense dedication and masterful work on a fundamental problem in biology — how can different organisms generate light? — that was, ironically, far from the limelight before the Nobel.”
In 1961, Dr. Shimomura, then a researcher at Princeton University, spent the summer scooping jellyfish, specifically the species Aequorea victoria, out of Puget Sound in Washington state. He was working for Frank Johnson, a Princeton marine biologist, who was interested in how the jellyfish glowed green when agitated.
They extracted a luminescent material from thousands of them and took it back to Princeton for further study. By February of the next year, Dr. Shimomura recalled in his autobiography at the Nobel website, they had obtained about 5 milligrams of a nearly pure luminescent protein, which they named aequorin. Dr. Shimomura also found traces of another protein that glowed green. That is now known as green fluorescent protein, or GFP.
Unlike most other light-producing proteins, which require a reaction with other chemicals to glow, green fluorescent protein turned green simply when ultraviolet light was shined on it.
Other scientists later determined the gene that produces GFP and were then able to stitch it into the DNA of other organisms. With that genetic modification, fluorescent snippets were attached to proteins that biologists were interested in.
Proteins are the machinery of cells, doing the work that keeps organisms alive. This became a revolutionary way for biologists to track the comings and goings and interactions of specific proteins, easily visible under a microscope — akin to attaching a GPS device to a person traveling through the tumult of a city.
“The importance of Dr. Shimomura’s contribution to contemporary biological discovery cannot be overstated,” Nipam Patel, director of the Marine Biological Laboratory in Woods Hole, Mass., where Dr. Shimomura worked from 1982 until 2001, said in a statement.
Osamu Shimomura was born on Aug. 27, 1928, in Kyoto, Japan, and his childhood and education were fractured by World War II. With his father serving in the Japanese army, he and his brother and sister were sent to live with grandparents near Nagasaki. At 16 he graduated from high school without ceremony or diplomas, at a factory where his class had been sent to repair fighter aircraft engines.
On Aug. 9, 1945, three days after the atomic bomb was dropped on Hiroshima, he saw an American B-29 bomber drop two or three parachutes. A few minutes later, a second B-29 appeared.
“At the moment I sat down on my work stool,” Dr. Shimomura wrote in his Nobel autobiography, “a powerful flash of light came through the small windows. We were blinded for about 30 seconds. Then, about 40 seconds after the flash, a loud sound and sudden change of air pressure followed. We were sure there was a huge explosion somewhere, but we didn’t know where.”
It was the atomic bomb being dropped on Nagasaki.
“The sky was rapidly filling with dark clouds,” he wrote, “and when I left the factory to walk home, about three miles away, a drizzling rain started. It was black rain.
“By the time I arrived home, my white shirt had turned gray. My grandmother quickly readied a bath for me. That bath might have saved me from the ill effects of the strong radiation that presumably existed in the black rain.”
After the war, he repeatedly applied to college and was repeatedly rejected. He was finally admitted to Nagasaki Pharmacy College in 1948, even though he was not planning to become a pharmacist. He discovered an interest in chemistry there and graduated at the top of his class in 1951. (Nagasaki Pharmacy College later became part of Nagasaki University.)
He worked as an assistant in a chemistry laboratory at Nagasaki for four years, then obtained a leave of absence to study for a year at Nagoya University. The professor he worked for, Yoshimasa Hirata, assigned him a seemingly impossible task: to try to crystallize a glowing organic compound called luciferin, found in a small crustacean in the coastal waters of Japan. A renowned zoologist at Princeton, E. Newton Harvey, had tried for 20 years to make crystals of luciferin and failed.
Dr. Shimomura succeeded after 10 months. His stay at Nagoya was extended a year, and he and Hirata published a paper describing their findings.
That attracted the attention of Johnson, a disciple of Harvey’s, who in 1959 offered the young scientist a job in his laboratory.
In the 1970s, Dr. Shimomura examined aequorin, green fluorescent protein, and other bioluminescent materials. In 1982, he moved to the Marine Biological Laboratory as a senior scientist, retiring in 2001.
Dr. Shimomura received the Asahi Prize, one of the most prestigious honors in Japan, in 2006.
He later noted that the Washington waters where he and his co-workers had collected so many Aequorea jellyfish — 850,000 over 19 trips between 1961 and 1988 — had become polluted, and that after 1990 the jellyfish became sparse, perhaps as a result of the Exxon Valdez oil spill in 1989. If the disappearance had occurred 20 years earlier, he would never have learned about aequorin or green fluorescent protein.
Dr. Shimomura leaves his wife, Akemi; a brother, Sadamu; a sister, Setsuko; a son, Tsutomu; a daughter, Sachi; and two grandchildren.