The Nobel Prize in Chemistry 2003 was awarded "for discoveries concerning channels in cell membranes" jointly with one half to Peter Agre "for the discovery of water channels" and with one half to Roderick MacKinnon "for structural and mechanistic studies of ion channels".
 

That the body's cells must contain specific channels for transporting water was suspected as early as the middle of the nineteenth century. However, it was not until 1988 that Peter Agre succeeded in isolating a membrane protein that, a year or so later, he realised must be the long-sought-after water channel. The other type of membrane channel which is the subject of this year's Prize is the ion channel. Roderick MacKinnon surprised the whole research community when in 1998 he was able to determine the spatial structure of a potassium channel. Thanks to this contribution we can now “see” ions flowing through channels that can be opened and closed by different cellular signals.
 

Prize amount: SEK 10 million, will be shared equally among the Laureates.