The molecular mechanism of selective and active transport in a Na + /Ca 2+ exchanger.

exchanger (NCX). This protein pertains to a prominent family of membrane transporters involved in cardiac diseases. The simulation results, validated with previous biophysical and biochemical experiments, provide new fundamental insight into the transport process of the NCX family, explaining at the molecular level their known selectivity and exchange stoichiometry. Hence, the emergent mechanism presented here expands our understanding of the basic principles governing the function of secondary active transporters.