"They are moving fast because they are bumping each other," Catterall said. "The movement of millions of molecules per second generates 15 pico amps a miniscule electrical current, only one trillionth the size of the current in an electric wall socket, but enough to drive a cell signal."
"The details of the structure told us exactly how calcium ions go through this particular type of cell membrane pore, and why sodium ions don't," Zheng added. "We were surprised and pleased that this seems to resolve in a clear way an important mechanism that has been unclear for a long time."
The study was conducted on a bacterial ion channel because mammalian ion channels would have been too big and complicated to be used as a model to obtain structural data, according to Zheng and Catterall. The approach the team took, they said, was a shortcut to obtain the information needed. The new understanding is likely to be applicable to such diverse scientific fields as the neurosciences, endocrinology, cardiovascular physiology, and cell biology.
"This information might also be important in the development of new drugs that act upon calcium channels," Catterall said. "Understanding the structure and function of the calcium channel might help researchers more accurately target drugs to bind exact areas of the channel to perform their therapeutic actions. These new compounds may work better with fewer side effects. For example, researchers are hoping to design safer medications for chronic pain."
|Contact: Leila Gray|
University of Washington