title: Nanopore translocation dynamics of a single DNA-bound protein.
abstract: We study the translocation dynamics of a single protein molecule attached to a double-stranded DNA that is threaded through a solid-state nanopore by optical tweezers and an electric field (nanopore force spectroscopy). We find distinct asymmetric and retarded force signals that depend on the protein charge, the DNA elasticity and its counterionic screening in the buffer. A theoretical model where an isolated charge on an elastic, polyelectrolyte strand is experiencing an anharmonic nanopore potential was developed. Its results compare very well with the measured force curves and explain the experimental findings that the force depends linearly on the applied electric field and exhibits a small hysteresis during back and forth translocation cycles. Moreover, the translocation dynamics reflects the stochastic nature of the thermally activated hopping between two adjacent states in the nanopore that can be adequately described by Kramers rate theory.
authors.affiliation: Fakultät für Physik, Universität Bielefeld, Universitätsstrasse 25, 33615 Bielefeld, Germany.
authors.forename: Andre
authors.initials: A
authors.lastname: Spiering
authors.forename: Sebastian
authors.initials: S
authors.lastname: Getfert
authors.forename: Andy
authors.initials: A
authors.lastname: Sischka
authors.forename: Peter
authors.initials: P
authors.lastname: Reimann
authors.forename: Dario
authors.initials: D
authors.lastname: Anselmetti
mesh_terms: D004268:DNA-Binding Proteins / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D058608:Nanopores; D036103:Nanotechnology; D010316:Particle Size; D013499:Surface Properties
chemical_list: D004268:DNA-Binding Proteins