In vitro Condensation of Mixed-Stranded DNA

Mixed-stranded;DNA;Condensation;Single-stranded

Santai, Catherine Theresa ; Chemistry and Biochemistry

University:Georgia Institute of Technology

Department:Chemistry and Biochemistry

关键词: Mixed-stranded;    DNA;    Condensation;    Single-stranded;   

Others  :  https://smartech.gatech.edu/bitstream/1853/14043/1/santai_catherine_t_200612_phd.pdf

美国|英语

来源: SMARTech Repository

【 摘 要 】

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.