Electrophysiological characterization of the archaeal transporter NCX_Mj using solid supported membrane technology.

Sodium-calcium exchangers (NCXs) are membrane transporters that play an important role in Ca(2+) homeostasis and Ca(2+) signaling. The recent crystal structure of NCX_Mj, a member of the NCX family from the archaebacterium Methanococcus jannaschii, provided insight into the atomistic details of sodium-calcium exchange. Here, we extend these findings by providing detailed functional data on purified NCX_Mj using solid supported membrane (SSM)-based electrophysiology, a powerful but unexploited tool for functional studies of electrogenic transporter proteins.