VOLUME 12, NUMBER 20 • APRIL 20, 2001

MacKinnon Wins Gairdner International Award

Rockefeller alumnus Bertil Hille also is a recipient

Rockefeller University neurobiologist Roderick MacKinnon has been named a recipient of the 2001 Gairdner International Award. This award, bestowed for "outstanding contributions by medical scientists whose work will significantly improve the quality of life," is one of the most prestigious international awards in medical research.

Roderick MacKinnon shares the 2001 Gairdner International Award with Bertil Hille and Clay Armstrong. Harvard’s Marc Kirschner also received the award.

MacKinnon, head of Rockefeller’s Laboratory of Molecular Neurobiology and Biophysics and an investigator with the Howard Hughes Medical Institute, shares this award with Bertil Hille, a Rockefeller University alumnus who is a professor of physiology and biophysics at the University of Washington, and Clay M. Armstrong, a professor in the Department of Physiology at the University of Pennsylvania School of Medicine. In 1999, the same three researchers shared the Lasker Award for Basic Medical Research.

Marc Kirschner, head of the Department of Cell Biology at Harvard Medical School, also is a recipient of this year’s award. In addition, Henry Friesen, who received the Gairdner International Award in 1977, received the Gairdner Foundation 2001 Wightman Award for his work as chair of the Board of Genome Canada.

The Gairdner Foundation began awarding the Gairdner International Award in 1959. Of the past 251 International Award winners, 54 have gone on to win a Nobel Prize. Among the many Rockefeller scientists who have received the Gairdner Award are Arnold and Mabel Beckman Professor Robert Roeder, Vincent Astor Professor James E. Darnell Jr., John D. Rockefeller Jr. Professor Günter Blobel and Professor Emeritus Vincent Dole.

The science behind the prize

In 1998, MacKinnon’s laboratory solved the structure of the potassium ion channel. The three-dimensional image of the channel was featured on the cover of Science magazine, which labeled this breakthrough one of the 10 biggest science stories of the year.

The transfer of potassium ions across cell membranes has long been understood as an essential activity for many life-sustaining functions. The proper balance of these ions is essential for fundamental operations, such as the transmission of nerve impulses throughout the body and brain. But until MacKinnon captured an image of the channel, it was not well understood how the process actually worked.

Shaped like tiny doughnuts floating in oil, ion channels perform the dual functions of gateway and gatekeeper. The holes in the doughnut form the gateway through which the ions flow. However, these holes, or pores, are endowed with special properties that enable different channel proteins to be selective as to which ions they allow passage.

MacKinnon sought to understand the structure of the protein and the answers to two compelling questions: What do these channels look like? And how are they able to allow passage of potassium ions while blocking other ions that are similar?

Using electrophysiological and biochemical approaches at Harvard, MacKinnon studied the interaction of the potassium channel with a specific toxin derived from scorpion venom and figured out that the toxin blocked the flow of ions by sitting directly on the pore of the channel. He then exploited the toxin to analyze the subunit structure, the moving gates and the ion conduction pathway of potassium channels.

MacKinnon calls the design of the potassium ion channel protein "elegant in its simplicity." The balance of electrical forces and chemical bonds inside the protein not only send potassium ions through the channel rapidly but also keeps out most other ions. MacKinnon’s research may play an important role in the development of drugs to deal with diseases ranging from diabetes to heart problems.