Condensed DNA in lipid microcompartments.

DNA was studied in lipid reverse micelles with the aim of investigating the interactions of DNA with lipids in a restricted compartment with minimal water content. Circular dichroic (CD) spectra of DNA at low water content showed the characteristic polymer-salt-induced (psi) spectra of condensed DNA. Dynamic light scattering showed a peak around a radius of 400 nm (corresponding to DNA-containing micelles), and a peak around 2.5 nm (corresponding to "empty" micelles). Fourier Transform-IR (FT-IR) spectroscopy was carried out and analyzed in terms of three distinct states of water inside the micelle water pool, where the local concentration of DNA reached an estimated value of ca. 600 mg/mL, comparable to that found in restricted biological compartments.