Specific recognition of telomeric multimeric G-quadruplexes by a simple-structure quinoline derivative

Area of Science:

• Biophysical Chemistry
• Molecular Biology
• Chemical Biology

Background:

• Highly sensitive fluorescence probes are crucial for detecting telomeric multimeric G-quadruplexes.
• Existing probes often lack the required specificity and selectivity for these structures.
• Developing selective probes remains a significant challenge in G-quadruplex research.

Purpose of the Study:

• To develop a novel, highly selective, and sensitive fluorescence probe for telomeric multimeric G-quadruplexes.
• To utilize a simple quinoline derivative, BEPQ-1, as a switch-on sensor.
• To investigate the binding mechanism and potential applications of BEPQ-1.

Main Methods:

• Utilized a commercially available quinoline derivative, BEPQ-1, as a fluorescence probe.
• Investigated the probe's response to telomeric multimeric G-quadruplexes via fluorescence intensity measurements.
• Determined the probe's selectivity, sensitivity, and detection limit.
• Analyzed the binding mode of BEPQ-1 to G-quadruplex structures.

Main Results:

• BEPQ-1 demonstrated a significant "switch-on" fluorescence enhancement (over 20-fold) upon binding to telomeric multimeric G-quadruplexes.
• The probe exhibited excellent selectivity and sensitivity, with a detection limit of 0.11 μM for TTA45 G-quadruplex.
• BEPQ-1 possesses a simple structure and small size, capable of binding to adjacent G-quadruplex units via π-π stacking.

Conclusions:

• BEPQ-1 represents the first simple-structure fluorescence probe specifically designed for telomeric multimeric G-quadruplexes.
• This finding provides a new strategy for designing specific G-quadruplex probes.
• The probe contributes to a better understanding of G-quadruplex structures and functions in telomeric regions.