John E. Walker

File:Sir John E. Walker.jpg

John E. Walker

Birth place	Halifax, England
Nationality	British
Known for	ATP synthase
Awards	Nobel Prize in Chemistry (1997)

John Ernest Walker (born 7 January 1941) is a British biochemist who was awarded the Nobel Prize in Chemistry in 1997 for his elucidation of the enzymatic mechanism underlying the synthesis of adenosine triphosphate (ATP). He shared the prize with Paul D. Boyer, who had proposed the binding change mechanism for ATP synthesis, and Jens C. Skou, who was recognized for his discovery of the Na⁺/K⁺-ATPase.

Early Life and Education

John E. Walker was born in Halifax, West Yorkshire, England. He attended Rastrick Grammar School and later went on to study at St Catherine's College, Oxford, where he received his Bachelor of Arts degree in Chemistry in 1964. He completed his doctoral studies at the University of Oxford, where he worked on the structure of cytochrome c under the supervision of Edward Abraham.

Research and Career

Walker began his career as a postdoctoral fellow at the University of Wisconsin–Madison and later at the University of Paris. In 1974, he joined the Medical Research Council's Laboratory of Molecular Biology in Cambridge, where he began his groundbreaking work on ATP synthase.

ATP Synthase

ATP synthase is a critical enzyme that synthesizes ATP, the energy currency of the cell, from adenosine diphosphate (ADP) and inorganic phosphate. Walker's research focused on the structure and function of this enzyme, which is located in the mitochondrial membrane.

Walker used X-ray crystallography to determine the structure of the F1-ATPase, a component of ATP synthase. His work provided detailed insights into the enzyme's rotary mechanism, which involves the rotation of the central stalk within the enzyme complex, driven by the flow of protons across the membrane. This rotation facilitates the binding and release of ATP and ADP, as described by Boyer's binding change mechanism.

Nobel Prize

In 1997, Walker was awarded the Nobel Prize in Chemistry alongside Paul D. Boyer and Jens C. Skou. Walker's contribution was the structural elucidation of ATP synthase, which confirmed and expanded upon Boyer's theoretical model. This work has had profound implications for our understanding of bioenergetics and cellular metabolism.

Later Work and Legacy

After receiving the Nobel Prize, Walker continued his research on ATP synthase and other related enzymes. He has published numerous papers and has been involved in various scientific collaborations. Walker's work has paved the way for further research into the mechanisms of energy conversion in biological systems.

Also see

• ATP synthase
• Paul D. Boyer
• Jens C. Skou
• Nobel Prize in Chemistry
• X-ray crystallography