2011/03/15 by Sandra Engel, Anna Alemany, Nuria Forns +2
Biochemistry, Genetics and Molecular Biology · Chemistry · Physics and Astronomy · #Advanced Physical and Chemical Molecular Interactions #DNA and Nucleic Acid Chemistry #Force Microscopy Techniques and Applications #cond-mat.stat-mech #physics.bio-ph
paper · pdf · doi:10.1080/14786435.2011.557671
published as Philosophical Magazine, 91: 13, 2049 -- 2065 · 17 pages, 12 figures
openalex publication_date 2011/03/15 · arxiv created 2011/06/10 · arxiv updated 2011/06/13 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/29
Single-molecule experiments provide new insights into biological processes hitherto not accessible by measurements performed on bulk systems. We report on a study of the kinetics of a triple-branch DNA molecule with four conformational states by pulling experiments with optical tweezers and theoretical modelling. Three distinct force rips associated with different transitions between the conformational states are observed in the folding and unfolding trajectories. By applying transition rate theory to a free energy model of the molecule, probability distributions for the first rupture forces of the different transitions are calculated. Good agreement of the theoretical predictions with the experimental findings is achieved. Furthermore, due to our specific design of the molecule, we found a useful method to identify permanently frayed molecules by estimating the number of opened base-pairs from the measured force jump values.