Investigations on the liquid crystalline phases of cation-induced condensed DNA

Pillai, C. K. S. ; Sundaresan, Neethu ; Radhakrishna Pillai, M. ; Thomas, T. ; Thomas, T. J. (2005) Investigations on the liquid crystalline phases of cation-induced condensed DNA Pramana - Journal of Physics, 65 (4). pp. 723-729. ISSN 0304-4289

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Official URL: http://www.ias.ac.in/pramana/v65/p723/abs.htm

Related URL: http://dx.doi.org/10.1007/BF03010460

Abstract

Viral and nonviral condensing agents are used in gene therapy to compact oligonucleotides and plasmid DNA into nanostructures for their efficient transport through the cell membranes. Whereas viral vectors are best by the toxic effects on the immune system, most of the nonviral delivery vehicles are not effective for use in clinical system. Recent investigations indicate that the supramolecular organization of DNA in the condensed state is liquid crystalline. The present level of understanding of the liquid crystalline phase of DNA is inadequate and a thorough investigation is required to understand the nature, stability, texture and the influence of various environmental conditions on the structure of the phase. The present study is mainly concerned with the physicochemical investigations on the liquid crystalline transitions during compaction of DNA by cationic species such as polyamines and metallic cations. As a preliminary to the above investigation, studies were conducted on the evolution of mesophase transitions of DNA with various cationic counterion species using polarized light microscopy. These studies indicated significant variations in the phase behaviour of DNA in the presence of Li and other ions. Apart from the neutralization of the charges on the DNA molecule, these ions are found to influence selectively the hydration sphere of DNA that in turn influences the induction and stabilization of the LC phases. The higher stability observed with the liquid crystalline phases of Li-DNA system could be useful in the production of nanostructured DNA. In the case of the polyamine, a structural specificity effect depending on the nature, charge and structure of the polyamine used has been found to be favoured in the crystallization of DNA.

Item Type:Article
Source:Copyright of this articles belongs to Indian Academy of Sciences.
Keywords:Liquid Crystalline DNA; Alkali Metal Ions; DNA Condensation; Nanostructured DNA
ID Code:38304
Deposited On:03 May 2011 13:15
Last Modified:17 May 2016 21:12

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