As well as his daughter, his wife, Joan, survives him.
After he took over at the Hughes Institute, Dr. Choppin liked to tell his colleagues a story about meeting their famously reclusive benefactor. In 1938, Hughes, an accomplished aviator as well as an industrialist, was stopping in Baton Rouge to refuel, and Arthur Choppin took 9-year-old Purnell and his brother, Arthur Jr., to see him. They shook hands, but, he said, his primary memory was that Hughes was “very tall.”
Dr. Choppin graduated from high school at 16 and entered L.S.U., where he also attended medical school. He received his doctorate in 1953 and completed his residency at Washington University. He served in the Air Force, in Japan, from 1954 to 1955.
He began at Rockefeller University as a postdoctoral fellow and was named a professor in 1959. He later moved into administration, and was a vice president and dean of graduate studies when the Howard Hughes Medical Institute hired him away.
Howard Hughes had founded the institute in 1953, and later transferred his entire holdings in the Hughes Aircraft Company to it, for tax purposes, creating an awkward arrangement in which a medical-research nonprofit owned one of the country’s largest defense contractors.
Just weeks before Dr. Choppin arrived, the institute sold the company to General Motors for $5.2 billion, immediately making it one of the country’s wealthiest philanthropies.
In 1987, the institute’s president was forced to resign after a financial scandal, and Dr. Choppin was named to replace him. Over the next decade he built it into a leading source of funding for biomedical research, doling out some $4.5 billion to hundreds of scientists as well as for undergraduate and high school science education.