Investigation of Single-Molecule Kinetics Mediated by Weak Hydrogen Bonds within a Biological Nanopore

Abstract

The study of factors essential for protein-peptide interactions and protein pore-mediated peptide transport are of particular relevance in biology. Wild-type α-hemolysin was adopted as a "nanoreactor" in which perturbations of the current through a protein containing a lumen-residing, aryl-capped antimicrobial peptide were seen for the first time and studied at the single-molecule level. Energy and steric considerations hint that Met-aryl interactions between aromatic residues placed at a peptide's extremities and any of the methionines lining the α-hemolysin constriction region may be the primary cause of peptide stabilization within the lumen and may be particularly important to the peptide-α-hemolysin interaction.