Berlin 2012 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 24: Posters: DNA/RNA and Related Enzymes
BP 24.11: Poster
Donnerstag, 29. März 2012, 17:30–19:30, Poster A
Optical Tweezers Force Spectroscopy on Protein Nanopores in Lipid Bilayers — •Andy Sischka1, Lorena Redondo-Morata2, Helene Schellenberg1, Andre Spiering1, Sebastian Knust1, Katja Tönsing1, Fausto Sanz2, and Dario Anselmetti1 — 1Experimental Biophysics and Applied Nanosciences, Faculty of Physics, Bielefeld University — 2Physical Chemistry Department, University of Barcelona
We are aiming to investigate the controlled translocation of individual DNA molecules through protein nanopores with our quantitative 3D optical tweezes system, similarly to recent single molecule threading experiments through solid-state nanopores (nanopore force spectroscopy) [1, 2]. There, quantitative translocation forces and ionic current signals of individual DNA molecules and DNA-protein complexes were identified and related to the respective protein type and charge.
Since we want to improve our understanding of the molecular translocation dynamics and increase the sensitivity of the translocation force and the ionic current, we extend these experiments towards biological nanopores and membranes by measuring both current and forces acting on a single-stranded DNA molecule that will be threaded through a protein nanopore inside a lipid bilayer. This bilayer is immobilized on a Si3N4 membrane support by vesicle spreading or Langmuir-Blodgett transfer. We will discuss first results with single-pore forming proteins like alpha-hemolysin.
[1] A. Sischka et al.: J. Phys.: Condens. Matt. 22: 454121 (2010)
[2] A. Spiering et al.: Nano Letters 11: 2978 (2011)