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Walker, Sir John (Ernest)

atp energy molecular boyer

(1941– ) British molecular biologist: co-elucidator of the enzymatic synthesis of adenosine triphosphate (ATP).

From boyhood in West Yorkshire, Walker (son of a stone mason and an amateur musician) was interested in science, especially chemistry, an interest which took him to Oxford and then on to DPhil work there with Sir Edward Abraham on the antibiotic subtilin. A move to Madison in 1969 enhanced his knowledge of proteins and notably of enzymes. He learned at this time the novel method of finding amino acid sequences in proteins by mass spectrometric methods, and he worked on this with a master of the technique during a period in France. In 1978 he joined the MRC Lab of Molecular Biology in Cambridge, working mainly on the biosynthesis and function of adenosine triphosphate (ATP). This intriguing, not very complex molecule, known since 1929 and synthesized by in 1948, is the universal energy carrier in all living organisms. It captures the energy obtained by oxidation of nutrients and transfers it to biological reactions requiring energy, such as the building-up of cell components, contraction of muscles, and the transmission of nerve messages.

ATP is made in living cells by an enzyme, ATP-synthase, which like all such biological catalysts is a protein. Walker’s work from the 1980s onwards gave detailed knowledge (obtained notably by X-ray crystallography) of the active part of this enzyme: this together with the work of Paul D Boyer (1918– ) of UCLA and that of Jens C Skou (1918– ) of Aarhus University in Denmark gives a good picture of the formation and action of ATP. ATP synthase forms, as Boyer notes, a molecular machine, which rotates and produces three ATP molecules per turn. How ATP acts on muscle fibre to produce movement has since 1997 been examined by Yoshida in Tokyo: the story will continue. Walker moved to head the Dunn Nutrition Unit in Cambridge in 1998. Walker, Boyer and Skou shared the Nobel Prize for chemistry in 1997.

Walker, Wyatt T.(1929–) - Minister, civil rights activist, Becomes Minister and Civil Rights Leader, Heads Civil Rights Organization, Chronology [next] [back] Walker, Matthew(1906–1978) - Physician, surgeon, Chronology, Final Years and Legacy

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