Computer modeling shows crucial function of water molecules in proteins

Using molecular simulations that modeled a potassium channel and its immediate cellular environment, atom for atom, UChicago scientists have discovered that just 12 molecules of water cause the long post-activation recovery period required by such ion channels before they can function again. The research has revealed a new mechanism in the function of a nearly universal biological structure that will have broad implications, ranging from fundamental biology to the design of pharmaceuticals. "Our research clarifies the nature of this previously mysterious inactivation state. This gives us better understanding of fundamental biology and should improve the rational design of drugs, which often target the inactivated state of channels," said Benoît Roux, professor of biochemistry and molecular biology, whose team's findings were published online July 28 in Nature . Potassium channels, present in the cells of virtually all living organisms, are core components in bioelectricity generation and cellular communication. Required for functions such as neural firing and muscle contraction, they serve as common targets in pharmaceutical development. These proteins act as a gated tunnel through the cell membrane, controlling the flow of small ions into and out of cells.