Sliding Columnar Phase of DNA-Lipid Complexes

TL;DR

This paper proposes a model for DNA-lipid complexes revealing a novel phase with long-range orientational order but lacking positional correlations, characterized by unique structural properties like an unusual X-ray structure factor.

Contribution

It introduces a new equilibrium phase in DNA-lipid complexes with distinct orientational and positional correlation properties, expanding understanding of their structural behavior.

Findings

Identification of a new phase with long-range orientational order

Characterization of the phase's unique X-ray structure factor

Demonstration of the model's implications for DNA-lipid complex structure

Abstract

We introduce a simple model for DNA-cationic-lipid complexes in which galleries between planar bilayer lipid lamellae contain DNA 2D smectic lattices that couple orientationally and positionally to lattices in neighboring galleries. We identify a new equilibrium phase in which there are long-range orientational but not positional correlations between DNA lattices. We discuss properties of this new phase such as its X-ray structure factor S(r), which exhibits unusual exp(- const.ln^2 r) behavior as a function of in-plane separation r.