Nanopore-based Single Molecule Determination of Polymer-cation Binding and Membrane Protein Dynamics
Joseph E. Reiner, John J. Kasianowicz, Joseph W. Robertson
Polyethylene glycol (PEG) is a ubiquitous charge-neutral polymer having several useful properties. It has been used to estimate the diameter of functioning nanopores. In this talk I will describe how the detailed analysis of PEG induced current blockades from a single alpha hemolysin channel in an unsupported lipid bilayer can be used to estimate step-wise changes in the structure of a functioning alpha hemolysin nanopore to < 1 Å. I will also describe a thermodynamic model that estimates the binding strength of cations to single PEG molecules from both the magnitude of PEG induced current blockades and the mean residence time of PEG within the nanopore.