When translocation dynamics becomes anomalous

Abstract

Recent single molecule experiments probing the passage process of a short single-stranded DNA (ssDNA) through a membrane channel (translocation) allow to measure the passage time distribution. Building on a recent modelling approach (D. K. Lubensky and D. R. Nelson, Biophys. J. 77, 1824 (1999)), which has been demonstrated to be valid for chains of up to $\simeq 300$ nucleotides and therefore well applies to the system we have in mind, we discuss the consequences if the associated dynamics is not of Markov origin, but if strong memory effects prevail during the translocation. Motivation is drawn from recent results indicating that the distribution of translocation times is broader than predicted by simple Markovian models based on Brownian motion.