Dresden 2014 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 13: Posters: DNA/RNA and related enzymes

BP 13.1: Poster

Dienstag, 1. April 2014, 09:30–12:30, P1

Local melting of ds-DNA within ultrathin amphiphilic films — •Caroline Falk, Hua Liang, Nikolai Severin, and Jürgen P. Rabe — Department of Physics Humboldt-Universität zu Berlin

DNA-replication is an important process in the human body. Replication of double-stranded (ds)-DNA requires its local unwinding, i.e. melting into two single strands (1). DNA, when stretched in solution, overwinds and melts (2). This was argued to give insight onto the replication mechanism. It is difficult, however, to access the direct conformational changes during stretching in solution. Preliminary work has demonstrated that this transition can be investigated on a graphite surface, pre-coated with an amphiphilic layer imaged with scanning force microscopy (3). ds-DNA can be stretched by an amphiphilic layer. This leads to a local splitting of the ds-DNA into two single strands and overwinding of the rest of the vector ds-DNA. This effect can be analyzed as a function of plasmid length and base sequences. We demonstrate here our efforts to identify the location of the local melting within the ds-DNA by marking specific locations within the DNA.

(1) D.Coman, I.M.Russu, Journal of Biological Chemistry 280, 20216 (2005).

(2) J.Adamcik, S.Tobenas, G.Di Santo, D.Klinov, G.Dietler, Langmuir, 25, 3159 (2009).

(3) H.Liang, W.Zhuang, N.Severin, J.P.Rabe Control of Single DNA Conformation on a Nanostructured Template (to be published).