(1956– ). An American born in Burlington, MA, who won the Nobel Prize for chemistry in 2003 for his pioneering work discovering channels in cell membranes, in particular for the structural and mechanistic studies of ion channels. He received a B.A. in biochemistry from Brandeis University and an M.D. from Tufts University School of Medicine. MacKinnon is a member of the National Academy of Sciences and was awarded the 1999 Albert Lasker Basic Medical Research Award.