Ion Permeation by a Folded Multiblock Amphiphilic
Oligomer Achieved by Hierarchical Construction of Self-Assembled Nanopores
- Publication date
- Publisher
Abstract
A multiblock
amphiphilic molecule <b>1</b>, with a tetrameric
alternating sequence of hydrophilic and hydrophobic units, adopts
a folded structure in a liposomal membrane like a multipass transmembrane
protein, and is able to transport alkali metal cations through the
membrane. Hill’s analysis and conductance measurements, analyzed
by the Hille equation, revealed that the tetrameric assembly of <b>1</b> forms a 0.53 nm channel allowing for permeation of cations.
Since neither <b>3</b>, bearing flexible hydrophobic units and
forming no stacked structures in the membrane, nor <b>2</b>,
a monomeric version of <b>1</b>, is able to transport cations,
the folded conformation of <b>1</b> in the membrane is likely
essential for realizing its function. Thus, function and hierarchically
formed higher-order structures of <b>1</b>, is strongly correlated
with each other like proteins and other biological macromolecules