By Sean Henahan, Access Excellence

Professor Paul D. Boyer, University of California, Los Angeles, USA, and Dr. John E. Walker, Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom were recognized for their elucidation of the enzymatic mechanism underlying the synthesis of adenosine triphosphate (ATP), along with Professor Jens C. Skou, Aarhus University, Denmark who first discovered the ion-transporting enzyme, Na+, K+-ATPase.

 "The three laureates have performed pioneering work on enzymes that participate in the conversion of the "high energy" compound adenosine triphosphate," notes the citation by the Royal Swedish Academy of Sciences.

Adenosine is a nucleoside comprising adenine linked to D-ribose through a beta-glycoside bond. Phosphorylated forms of adenosine (AMP, ADP, and ATP) are the major compounds involved in energy transfer in biological systems. ATP acts as an energy source for many cellular processes. Indeed, an active cell needs about two million ATP molecules per second to function.

ATP serves as an energy transporter in all living organisms. The compound captures the chemical energy released by the combustion of nutrients and transfers it to reactions that require energy, e.g. the building up of cell components, muscle contraction, transmission of nerve messages and many other functions.

Drs. Boyer and Walker conducted fundamental research on how the enzyme ATP synthase catalyses the    formation of ATP. Boyer and colleagues have proposed, on the basis of biochemical data, a mechanism for how ATP is formed from adenosine diphosphate (ADP) and inorganic phosphate. Walker and his colleagues established the structure of the enzyme and verified the mechanism proposed by Boyer.

Jens C. Skou receives half of the $1 million prize for his discovery of the enzyme sodium, potassium-stimulated adenosine triphosphatase (Na+, K+-ATPase). This enzyme maintains the balance of sodium and potassium ions in the living cell. Both enzymes are bound to membranes in the cell and linked with the transport of ions through these - but for different reasons.

ATP was first discovered in 1929 by the German chemist Karl Lohmann. The English chemist Alexander Todd helped clarify its structure and became the first to synthesize ATP in 1948. Todd won the Nobel Prize in 1957. Another Nobel Laureate, Fritz Lipmann demonstrated that ATP is the universal carrier of chemical energy in the cell.