The Nobel Academy has awarded this year's Nobel Prize in Chemistry to two Americans, for helping to unravel the mystery of how the body regulates the flow of substances in and out of cells.

Peter Agre and Roderick MacKinnon were awarded the 2003 prize in chemistry for discovering and elucidating the structure of water and ion channels in the cell membrane, work that may one day aid in the development of future drugs that act on these channels.

Agre, born in 1949, is professor of Biological Chemistry and professor of Medicine at Johns Hopkins University School of Medicine. Although scientists have long known that maintaining the proper water pressure within cell walls is essential for survival, it was not until 1988 that Agre isolated a protein in the cell membrane that he later discovered to be the channel that passes water in and out of the cell.

Agre's long-awaited discovery led to a cascade of subsequent studies into the make-up and mechanics of water channels in a range of species, and researchers can now trace a water molecule's path through the cell membrane and understand the channel''s selectivity for water.

Forty-seven-year-old Roderick MacKinnon, a professor of molecular neurobiology and biophysics at Rockefeller University, was honored for his work in unraveling the structure of potassium ion channels, down to the atomic level. In 1998, he revealed the spatial structure of the potassium channel, enabling researchers to now visualize the flow of ions through the channels.

MacKinnon demonstrated “what it meant to be an ion channel,” Bert Shapiro, branch chief of cell biology at the National Institute of General Medical Sciences (NIGMS) told The Scientist. NIGMS is a component of the National Institutes of Health, which has funded the work of both laureates.

Shapiro said that MacKinnon's achievements are particularly remarkable because he is relatively young and did not start his career with the intention of becoming an expert in elucidating membrane channel structure. MacKinnon originally wanted to be a physician, Shapiro said, but moved into science because it excited him. “He is sort of a self-taught crystallographer, and he is really a premier crystallographer,” Shapiro said.

Many drugs act on membrane channels, and discoveries that help researchers understand how substances move through these channels could have important future implications for human health, said James Cassatt, director of the Division of Biology and Biophysics at the NIGMS.

“As people begin to develop new pharmaceuticals that block channels, they will go back to structure,” and the work of Agre and MacKinnon, Cassatt told The Scientist. He predicted that the achievements of these newest laureates could have an “enormous” impact on pharmaceuticals in the next 5 years.

The chemistry prize follows Monday's (October 6) announcement of the prize in medicine or physiology to magnetic resonance imaging researchers.