G-quadruplexes (GQs) are important biomarkers and drug targets because of their regulatory role in transcription. Adherence to the GQ consensus sequence is often used to predict new GQ regions, but this approach can overlook potential candidates that form imperfect G-Quadruplex (imGQs) structures containing bulges, vacancies or mismatches.
Multiple imGQs were characterized with regards to secondary structure, thermal stability and interaction with small molecule ligands. By making use of CD spectroscopy and orthogonal absorbance and fluorescence data obtained with a Chirascan, imGQs were shown to behave similarly to perfect GQs, suggesting that GQs with potential regulatory function are more abundant than commonly assumed.