A New Antiport Mechanism Using the Abnormal Adsorption of Ions.

Ion pumps are crucial in many biological and nonbiological systems, but their mechanisms have not yet been completely elucidated. Generally, it is understood that ion pumps are implemented by functional proteins. In this investigation, we have proposed a new model for the antiport process, which does not involve a "lever molecule". In this model, abnormal adsorption of the ions occurs in charged nanopores, which can adsorb more transport ions in the lower concentration phase than the higher one. The classical density functional theory (CDFT) confirms the existence of this abnormal adsorption, and the density profiles indicate that it is due to the competition between the transport and background ions. This antiport mechanism thus provides new insights into the function and design of ion pumps.