Dynamic Partitioning of Neutral Polymers into a Single Ion Channel

摘要: Polymers partitioning into highly confined spaces can be studied using single nanometer-scale pores formed by protein ion channels. The ionic conductance of a channel depends on the state occupancy pore polymer and serves as measure partitioning. Specifically, movement neutral causes reduction channel’s conductance. mean is used to determine partition coefficient fluctuations report rates at which exchanges between bulk pore. Three theoretical approaches describe steric interaction (hard spheres, random flight model, scaling theory) fail poly(ethylene glycol) two structurally chemically different channels (Staphylococcus aureus α-hemolysin alamethicin). In particular, these theories cannot account for sharp molecular weight dependence coefficient.