Phase behavior of semidilute polyelectrolyte mixtures of F-actin and DNA

ORAL

Abstract

We investigate the phase behavior of semidilute mixtures of polyelectrolyte DNA coils and F-actin rods. F-actin has a persistence length of $\sim $10 microns and a linear charge density of -1e/0.25nm. DNA has a persistence length of $\sim $50nm and a linear charge density of --1e/0.17nm. Confocal and polarized microscopy data show that actin-DNA phase separates into ribbon-like birefringent domains of nematic F-actin and a disordered mesh of DNA coils. Synchrotron Small Angle X-ray Scattering (SAXS) show that DNA compresses F-actin into an ultradense dense nematic phase. The spacing between nematic F-actin domains shows a power-law dependence on DNA concentration which is independent of the contour lenth of either DNA or F-actin.

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Authors

  • John Butler

    • Department of Materials Science, Univeristy of Illinois at Urbana Champaign

  • Olena V. Zribi

    • Department of Physics, University of Illinois at Urbana Champaign
    • University of Illinois at Urbana-Champaign, Dept. of Physics

  • Gerard C. L. Wong

    • Department of Materials Science and Engineering, Department of Physics, Department of Bioengineering, University of Illinois at Urbana Champaign

  • Ramin Golastanian

    • Isaac Newton Institute for Mathematical Sciences, Cambridge, UK, Institute for Advanced Studies in Basic Sciences, Zanjan, Iran