Structural polymorphism of DNA-dendrimer complexes

Phys Rev Lett. 2003 Aug 15;91(7):075501. doi: 10.1103/PhysRevLett.91.075501. Epub 2003 Aug 11.


DNA condensation in vivo relies on electrostatic complexation with small cations or large histones. We report a synchrotron x-ray study of the phase behavior of DNA complexed with synthetic cationic dendrimers of intermediate size and charge. We encounter unexpected structural transitions between columnar mesophases with in-plane square and hexagonal symmetries, as well as liquidlike disorder. The isoelectric point is a locus of structural instability. A simple model is proposed based on competing long-range electrostatic interactions and short-range entropic adhesion by counterion release.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cations / chemistry
  • DNA / chemistry*
  • Histones / chemistry
  • Models, Biological*
  • Models, Molecular
  • Polypropylenes / chemistry*
  • Static Electricity


  • Cations
  • Histones
  • Polypropylenes
  • DNA