Jane Coffin Childs Memorial Fund Fellow, NIH, 1974-75 Assistant Professor of Chemistry, Yale University, 1975-81 Associate Professor of Chemistry, Yale University, 1981-84 Professor of Chemistry and Biochemistry, University of Maryland, 1984-1994 Professor of Biochemistry, University of Illinois, Urbana-Champaign, 1994-present Professor of Chemistry, University of Illinois, Urbana-Champaign, 1994-present Head of Biochemistry, University of Illinois, Urbana-Champaign, 1994-2004 Gutgsell Chair, University of Illinois, 2004-present