A winner of the 1968 Nobel Prize in physiology or medicine, Khorana devoted much of his scientific career to unraveling the genetic code and the mechanisms by which nucleic acids give rise to proteins. “Gobind was a brilliant, path-breaking scientist, a wise and considerate colleague, and a dear friend to many of us at MIT,” said Chris Kaiser, MacVicar Professor of Biology and head of the Department of Biology, in an email announcing the news to the department’s faculty.
Khorana was born in India in 1922, in a small village called Raipur, in the region of Punjab that is now part of Pakistan. He was the youngest in a Hindu family of one daughter and four sons; his father was a patwari, an agricultural taxation clerk in the British Indian system of government. In an autobiographical note written upon winning the Nobel Prize, Khorana wrote: “Although poor, my father was dedicated to educating his children and we were practically the only literate family in the village inhabited by about 100 people.”
Khorana attended high school in the nearby city of Multan before enrolling in Punjab University, where he received his bachelor’s degree in 1943 and master’s in 1945, both in chemistry and biochemistry. Upon graduating, he received a fellowship from the Indian government to study at the University of Liverpool in the U.K., where he received his PhD in 1948.
He did postdoctoral work at Switzerland’s Federal Institute of Technology, where he met his wife, the late Esther Elizabeth Sibler. Feeling lost in a new country, Khorana later wrote: “Esther brought a consistent sense of purpose in my life at a time when, after six years’ absence from the country of my birth, I felt out of place everywhere and at home nowhere.”
After returning to the U.K. for another postdoc position in Cambridge, Khorana and his wife created a new home together in Vancouver, Canada, where he took a job at the British Columbia Research Council in 1952.
“Gobind was so excited that he was going to start a lab of his own. He looked at the map of Canada, saw where Vancouver was for the first time, and off he went,” says colleague Uttam Rajbhandary, MIT’s Lester Wolfe Professor of Molecular Biology, recalling Khorana’s telling of how he accepted the position.
Khorana stayed in Vancouver for eight years, continuing his pioneering work on proteins and nucleic acids while raising two daughters, Julia Elizabeth and Emily Anne, and a son, Dave Roy. In 1960, he went to the University of Wisconsin at Madison, where he became co-director of the Institute for Enzyme Research.
It was at Wisconsin that Khorana and colleagues worked out the mechanisms by which RNA codes for the synthesis of proteins, leading to the Nobel Prize in 1968, which Khorana shared with Robert Holley of Cornell University and Marshall Nirenberg of the National Institutes of Health. Khorana was among the pioneers of the now-familiar series of three-nucleotide codons that signal to the cell which amino acids to use in building proteins — for example, uracil-cytosine-uracil, or UCU, codes for the amino acid serine, while CUC codes for leucine.
After discovering this key biological code, Khorana became interested in replicating the process synthetically. In 1970 he joined MIT, where he continued at the forefront of the ballooning field of genetics.
Shortly after arriving at the Institute, Khorana — along with colleagues — announced the synthesis of two different genes crucial to protein building. In a major breakthrough in 1976, they managed to complete the synthesis of the first fully functional manmade gene in a living cell. This method of chemically synthesizing genes made possible controlled, systematic studies of how genetic structure influences function.
In the decades that followed, Khorana became interested in other cellular components, including biomembranes and, in the visual system, rhodopsin — the pigment on the eye’s retina that is responsible for the first step in the biological perception of light. He retired from the MIT faculty in 2007.
In addition to his strong research ethic, Khorana took pride in mentoring younger scientists. “Even while doing all this research, he was always really interested in education, in students and young people,” says his daughter, Julia Khorana ’75. “After he retired, students would come to visit and he loved to talk to them about the work they were doing. He was very loyal to them, and they were very loyal to him, too.”
Rajbhandary says he will remember Khorana for his drive and focus, but also his humility. “As good as he was, he was one of the most modest people I have known,” he says. “What he accomplished in his life, coming from where he did, is truly incredible.”
In addition to the Nobel, Khorana won many other professional awards, including the Louisa Gross Horwitz Prize from Columbia University and the Lasker Foundation Award for Basic Medical Research, both in 1968; the Willard Gibbs Medal of the Chicago section of the American Chemical Society, in 1974; the Gairdner Foundation Annual Award, in 1980; and the Paul Kayser International Award of Merit in Retina Research, in 1987. He was a member of the National Academy of Sciences and a fellow of the American Academy of Arts and Sciences, among other distinguished professional memberships.
Khorana is survived by his daughter, Julia, and son, Dave. A memorial service is being planned.