Water molecules rapidly flow in single file through the aquaporin channel – a membrane-spanning protein. Aquaporin selectively binds water molecules and prevents other molecules from entering the channel. While the process is not fully understood, many researchers believe that the water molecules roll over as they bind with the first of 2 asparagine located at the narrowest part of the channel. Each water molecule then binds with the second asparagine before moving through the rest of the channel. Our Aquaporin Channel Mini Model separates to show water molecules passing through the channel.
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".