Isothermal folding of G-quadruplexes

Area of Science:

• Biochemistry
• Biophysical Chemistry
• Molecular Biology

Background:

• Thermodynamic studies complement structural data (NMR, X-ray crystallography) for G-quadruplexes.
• Understanding G-quadruplex energetics is key to interpreting their formation and reactivity.
• Cation binding is intrinsically linked to G-quadruplex folding.

Purpose of the Study:

• To present protocols for studying cation-driven G-quadruplex folding.
• To characterize the relationship between cation binding and G-quadruplex folding.
• To provide methods for monitoring folding and cation distribution at constant temperature.

Main Methods:

• Monitoring cation-driven G-quadruplex folding transitions using circular dichroism or absorbance.
• Determining free and bound cation distribution via a fluorescence indicator.
• Isothermal titration methods for studying G-quadruplex folding.

Main Results:

• Established protocols for observing G-quadruplex folding transitions.
• Quantified cation binding and its correlation with folding.
• Provided a comprehensive view of G-quadruplex folding thermodynamics.

Conclusions:

• Integrated biophysical techniques offer detailed insights into G-quadruplex folding.
• The linkage between cation binding and folding is quantitatively characterized.
• These methods are essential for understanding G-quadruplex stability and function.