JIM GILES

Membrane proteins control the flow of chemicals in and out of cells. source: Nature

Two structural biologists credited with transforming our understanding of how cells work have won the 2003 Nobel Prize in Chemistry.

Peter Agre, of Johns Hopkins University in Baltimore, and Roderick MacKinnon, of the Rockefeller University in New York, share the 10-million-Krona (US$1.3-million) award for their impact on biochemistry. But their insights into the shape and workings of the channels that let ions and water in and out of cells are also likely to underpin medical advances for decades to come.

MacKinnon is perhaps the most widely-tipped Nobel winner of recent years. The cell membrane channels he studies control the flow of ions and hence the voltage pulses between brain cells. In a landmark paper, published in 1998, he and colleagues unveiled the first detailed three-dimensional picture of the protein that makes up a channel that controls the flow of potassium ions¹.

When he went on to describe how such channels open, close and prevent other ions from entering, many colleagues felt that MacKinnon had earned a Nobel. "His work is a tour de force," says John Walker, a structural biologist at the University of Cambridge, UK. "The award is absolutely spot-on and richly deserved - I'm delighted."

Agre's breakthrough came about a decade earlier, when he cracked a problem that had survived more than a century of study. Biologists from the 1800s onwards knew that cells must have some way of absorbing water and flushing it out.

In 1988, Agre identified a protein that he suspected of doing the job². A few years later he showed that the molecule, now called aquaporin-1, forms a pore in the membrane that lets through water, but not other substances.

1. Doyle, D. A. et al. The Structure of the Potassium Channel: Molecular Basis of K+ Conduction and Selectivity. Science, 280, 69 - 77, doi:10.1126/science.280.5360.69 (1998). |Article|
2. Denker, B. M., Smith, B. L., Kuhajda, F. P. & Agre, P. Identification, purification, and partial characterization of a novel Mr 28,000 integral membrane protein from erythrocytes and renal tubules. Journal of Biological Chemistry, 263, 15634 - 15642, (1988). |Article|

（From: Nature Science Update）