Alpha-Hemolysin Channel Interaction with Neutral Polymers

Abstract

Polyethylene glycols (PEG) or dextran are among the neutral polymers used in single-channel conductance measurements to size the aqueous pore, to evaluate access resistance or to induce osmotic stress in polymer-excluded regions. The use of polymer partitioning into biological nanopores to size the aqueous pore of protein ion channels has become a common approach. While the basic principles of polymer behavior in restricted volumes are well established, little is known about the actual interaction of neutral polymer molecules with charged sites in membranes and channel proteins.