DNA condensation is the process in which an anionic polymer in combination with condensing agents undergoes a drastic reduction in volume and collapses into ordered structures. Double-stranded DNA has a uniform helical secondary structure, whereas single-stranded DNA is complex and adopts numerous different conformations. Novel mixed-stranded DNA molecules, with defined regions of both single-stranded and double-stranded secondary structures attached to one another in the same molecule, were created in this body of work. Mixed-stranded DNA was designed to be intermediate between its parent secondary structures in order to discover if mixed-stranded DNA will find a balance in terms of condensation properties as well. Mixed-stranded DNA was found to condense into minimally aggregated, globular particles in the presence of low mM concentrations of divalent transition metals in aqueous solvent at room temperature, a property not observed for either pure dsDNA or ssDNA. A model is presented to describe how mixed-stranded DNA -Mn2+, -Ni2+, and -Cd2+ condensates with the observed properties are produced. Multivalent-induced condensation of mixed-stranded DNA is also characterized and found to involve an unusual rod-like morphology in order to accommodate the secondary structures condensing independent of one another at different concentrations of multivalent cations. The attachment of a ss region to an otherwise ds molecule was found to greatly influence condensation properties of the entire molecule.
| Identifer | oai:union.ndltd.org:GATECH/oai:smartech.gatech.edu:1853/14043 |
| Date | 20 November 2006 |
| Creators | Santai, Catherine Theresa |
| Publisher | Georgia Institute of Technology |
| Source Sets | Georgia Tech Electronic Thesis and Dissertation Archive |
| Language | en_US |
| Detected Language | English |
| Type | Dissertation |
| Format | 869002 bytes, application/pdf |
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