Aquaporin

Aquaporins are integral membrane proteins that form pores in the membrane of biological cells. They are a family of membrane water channels. Some aquaporins transport also glycerol. There are thirteen known types of aquaporins in mammals. Six of these are located in the kidney. The structure of aquaporin was determined and the protein is made up of six transmembrane α-helices.

The Nobel Prize in Chemistry 2003 was awarded to Peter Agre for the discovery of aquaporins and also to Roderick MacKinnon for his work on the structure and operation of ion channels.