(1918– ). A chemist who won the Nobel Prize in 1997 for his work on elucidating the enzymatic mechanism by which ATP synthase (ATPase) catalyzes the synthesis of adenosine triphosphate (ATP), the energy source of living cells. He is a professor of biochemistry at the University of California, Los Angeles. He received a Ph.D. in Biochemistry in 1943 from the University of Wisconsin, Madison, U.S.A.See Walker, John E, Skou, Jens C.