ABSTRACT
Ligand responsiveness is one of the typical mechanisms in biological organization to trigger sophisticated channel switching. Here, we report a new type of helical trimer which can undergo transition between a hollow single helix and an intertwined double helix with no cavity by complexation and decomplexation of Cu ions. In addition, the one dimensional (1D) hollow helical tubes spontaneously generated from single helices via π-π interactions embedded into the lipid bilayers and displayed satisfactory channel stability and efficiency. With the addition of CuI ions and further extraction with ammonia, the disassembly and reassembly of 1D hollow helical tubes gave rise to the reversible switching of channel activity in situ inside the bilayers. The synthetic helical system provides the first model of reversible ligand-gated ion channel by means of dynamic transition between single and double helices, which will be available for developing intelligent artificial nanochannels for potential biological and medicinal applications.
Subject(s)
Coordination Complexes/chemistry , Ion Transport/drug effects , Phenanthrenes/chemistry , Triazoles/chemistry , Biomimetics , Copper/chemistry , Ligand-Gated Ion Channels/chemistry , Ligands , Lipid Bilayers/chemistry , Lipid Bilayers/metabolism , Molecular Conformation , Phosphatidylcholines/chemistry , Potassium/metabolismABSTRACT
Hierarchical self-assembly from a V-shaped ligand 2,9-di(pyridin-4-yl)-1,10-phenanthroline (DPP) to an initial interlocked dimer, further to a coordination polymer with an alternate linear and interlocked helical configuration and finally to a lamellar structure with an undulating surface was precisely achieved in sequence via the cooperativity of two-step Ag (i) coordination and π-π interactions for the first time.
