7/01/2008 PERMALINK
Understanding how molecules bind to a protein Adenosine triphosphate (ATP), a tiny molecule that packs a powerful punch, is the primary energy source for most of your cellular functions.

Now researchers at the University of Illinois Center for Biophysics and Computational Biology have identified a key step in the cellular recycling of ATP that allows your body to produce enough of it to survive. Without this cycling of ATP and its low-energy counterpart, adenosine diphosphate (ADP), into and out of the mitochondrion, where ADP is converted into ATP, life as we know it would end.

Researchers have for the first time simulated the binding of ADP to a carrier protein lodged in the inner membrane of the mitochondrion. It is the first simulation of the binding of a molecule to a protein. “The carrier is a reversible machine,” said biochemistry professor Emad Tajkhorshid, who led the study which was conducted by graduate student Yi Wang. “Both ATP and ADP can bind to it and make it to the other side using this transporter.” Their findings appear this week in Proceedings of the National Academy of Sciences. Watch movie of simulation.