Single-molecule kinetics and footprinting of DNA bis-intercalation: the paradigmatic case of Thiocoraline.

ABSTRACT: DNA bis-intercalators are widely used in molecular biology with applications ranging from DNA imaging to anticancer pharmacology. Two fundamental aspects of these ligands are the lifetime of the bis-intercalated complexes and their sequence selectivity. Here, we perform single-molecule optical tweezers experiments with the peptide Thiocoraline showing, for the first time, that bis-intercalation is driven by a very slow off-rate that steeply decreases with applied force. This feature reveals the existence of a long-lived (minutes) mono-intercalated intermediate that contributes to the extremely long lifetime of the complex (hours). We further exploit this particularly slow kinetics to determine the thermodynamics of binding and persistence length of bis-intercalated DNA for a given fraction

SUBMITTER: Camunas-Soler J 

PROVIDER: S-EPMC4357703 | biostudies-literature | 2015 Mar

REPOSITORIES: biostudies-literature