Читать книгу Chemistry and Biology of Non-canonical Nucleic Acids - Naoki Sugimoto - Страница 52

Upon triplex unfolding the absorbance at 260 nm is known to increase as a result of decreased base stacking, and the absorbance at 295 nm decreases, indicating the presence of cytosine: protonated cytosine base pairs (Hoogsteen base pairs). Similarly, the G-quadruplex unfolding can be monitored by the absorbance at 295 nm (see Chapter 4). The thermodynamic parameters for the intramolecular triplex and tetraplex can be calculated using Eqs. (3.3, 3.7, 3.8) described above if the unfolding process is two-state [14].