Two American researchers won the Nobel Prize in chemistry on Wednesday for studies of protein receptors that let body cells sense and respond to outside signals like danger or the flavor of food. Such studies are key for developing better drugs.The Royal Swedish Academy of Sciences said Robert Lefkowitz and Brian Kobilka had made groundbreaking discoveries, mainly in the 1980s, on an important family of receptors, known as G-protein-coupled receptors.

Lefkowitz, 69, is an investigator at the Howard Hughes Medical Institute and professor at Duke University Medical Center in Durham, North Carolina.Kobilka, 57, worked for Lefkowitz at Duke before transferring to Stanford University School of Medicine in California, where he is now a professor.