Single-Molecule Kinetic and Thermodynamic Studies of Cosolute-Influenced Nucleic Acid Conformational Transitions

<p>Over the last 40 years the number of biochemical functionalities attributed to nucleic acids\&nbsp;<span style="font-size: 13px; line-height: 1.6em;">has increased tremendously. This diverse array of chemical functionality is intimately coupled to\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">the spatial arrangement of atoms associated with these molecules. The three-dimensional\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">structures and functions of nucleic acids are known to be dependent on the concentration and\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">identity of solutes in solution. These nucleic acid cosolutes can be as simple and universal as\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">atomic metal cations that favorably interact with the negatively charged phosphate backbone of\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">nucleic acids and resulting in stabilization of electronegatively dense conformations.\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">Alternatively, they may be complex organic molecules that are able to promote conformational\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">transitions in certain RNA sequences responsible for regulating gene expression. Understanding\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">the biophysical principles responsible for these cosolutes-influenced conformational transitions\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">represents the primary objective of this work.</span></p>