Dresden 2006 – scientific programme

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AKB: Biologische Physik

AKB 20: Nano-Biomaterials and Devices

AKB 20.4: Talk

Thursday, March 30, 2006, 11:00–11:15, ZEU 255

Driving a DNA conformational switch with a pH oscillator — •Tim Liedl and Friedrich Simmel — Department für Physik, Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, 80539 München

DNA conformational changes occuring in artificially generated DNA structures can be used to produce motion on the nanometer scale. Such DNA-based nanodevices are either driven by hybridization events between complementary strands of DNA or by buffer-induced conformational changes. One prominent example of such a conformational change is the formation of the so-called i-motif, which is a folded four-stranded DNA structure characterized by noncanonical hemiprotonated cytosine-cytosine base-pairs. The transition of DNA strands prone to fold into the i-motif occurs in the pH range between 5 and 7. Usually, DNA devices are driven by the manual addition of fuel molecules or by the periodic variation of buffer conditions. In an attempt to produce self-running nanodevices which do not require intervention by an external operator, we here show that a DNA switch based on the i-motif can also be driven autonomously within a continuously stirred flow reactor in which periodic pH oscillations are generated by a nonequilibrium chemical process. The conformational changes are monitored simultaneously with the pH value in fluorescence resonance energy transfer experiments.