In 1960, he move to the US for a role at the Institute for Enzyme Research in the University of Wisconsin. It was there that he made his Nobel-worthy discovery and became a naturalized American citizen. In 1970, Khorana joined the faculty at the Massachusetts Institute of Technology as the Alfred P. Sloan professor of biology and chemistry, the position he held until he died on Nov. 9, 2011 at age 89.