| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Department of Pharmaceutical Sciences, University of Colorado Health Sciences Center, Denver, Colorado 80262
Correspondence: Address reprint requests to Mayank M. Patel, Dept. of Pharmaceutical Sciences, School of Pharmacy, C238 University of Colorado Health Sciences Center, 4200 E. Ninth Ave., Denver, CO 80262, Tel.: 303-315-0359; Fax: 303-315 6281; E-mail: mayank.patel{at}uchsc.edu.
The importance of understanding the dynamics of DNA condensation is inherent in the biological significance of DNA packaging in cell nuclei, as well as for gene therapy applications. Specifically, the role of ligand hydrophobicity in DNA condensation has received little attention. Considering that only multivalent cations can induce true DNA condensation, previous studies exploring monovalent lipids have been unable to address this question. In this study we have elucidated the contribution of the hydrophobic effect to multivalent cation- and cationic lipid-DNA binding and DNA collapse by studying the thermodynamics of cobalt hexammine-, spermine-, and lipospermine-plasmid DNA binding at different temperatures. Comparable molar heat capacity changes (
Cp) associated with cobalt hexammine- and spermine-DNA binding (23.39 cal/mol K and 17.98 cal/mol K, respectively) suggest that upon binding to DNA, there are insignificant changes in the hydration state of the methylene groups in spermine. In contrast, the acyl chain contribution to the
Cp of lipospermine-DNA binding (
Cp
=
Cp lipospermine
Cp spermine) is significant (220.94 cal/mol K). Although lipopermine induces DNA ordering into "tubular" suprastructures, such structures do not assume toroidal dimensions as observed for spermine-DNA complexes. We postulate that a steric barrier posed by the acyl chains in lipospermine precludes packaging of DNA into dimensions comparable to those found in nature.
This article has been cited by other articles:
![]() |
A. Ziegler and J. Seelig Binding and Clustering of Glycosaminoglycans: A Common Property of Mono- and Multivalent Cell-Penetrating Compounds Biophys. J., March 15, 2008; 94(6): 2142 - 2149. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. E. Hays, C. M. Jewell, Y. Kondo, D. M. Lynn, and N. L. Abbott Lipoplexes Formed by DNA and Ferrocenyl Lipids: Effect of Lipid Oxidation State on Size, Internal Dynamics, and {zeta}-Potential Biophys. J., December 15, 2007; 93(12): 4414 - 4424. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. B. Teif Ligand-Induced DNA Condensation: Choosing the Model Biophys. J., October 1, 2005; 89(4): 2574 - 2587. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |