Biophysical probing of the binding properties of a Cu(II) complex with G-quadruplex DNA: an experimental and computational study.

Telomerase inhibition through G-quadruplex stabilization by small molecules is of great interest as a novel anticancer therapeutic strategy. Here, we show that newly synthesized Cu-complex binds to G-quadruplex DNA and induces changes in its stability. This biophysical interaction was investigated in vitro using spectroscopic, voltammetric and computational techniques.

Spectroscopic and molecular modeling study on the separate and simultaneous bindings of alprazolam and fluoxetine hydrochloride to human serum albumin (HSA): with the aim of the drug interactions probing.

The objective of the present research is to study the interaction of separate and simultaneous of alprazolam (ALP) and fluoxetine hydrochloride (FLX) with human serum albumin (HSA) in phosphate buffer (pH 7.4) using different kinds of spectroscopic, cyclic voltammetry and molecular modeling techniques. The absorbance spectra of protein, drugs and protein-drug showed complex formation between the drugs and HSA.

Molecular crowding effects on conformation and stability of G-quadruplex DNA structure: insights from molecular dynamics simulation.

Intracellular space is highly crowded with different biomolecules such as proteins, nucleic acids and ions. Therefore molecular crowding is a crucial factor in determining the structure, stability and function of G-quadruplexs. The effect of crowding on the DNA G-quadruplexes structure and stability has been studied by experimental methods, but it hasn't been known how crowding agents stabilize the G-quadruplex structure in molecular level yet.

A fluorescent aptasensor for potassium ion detection-based triple-helix molecular switch.

Here, a biosensor based on a quadruplex-forming aptamer for the determination of potassium ion (K(+)) is presented. The aptamer was used as a molecular recognition element; it was adjacent to two arm fragments and a dual-labeled oligonucleotide serving as a signal transduction probe (STP) that is complementary of the arm fragment sequence. In the presence of K(+), the aptamer was displaced from the STP, which was accompanied by decreased signal.

Conformational switch of insulin-binding aptamer into G-quadruplex induced by K⁺ and Na⁺: an experimental and theoretical approach.

Guanine-rich sequences can form the G-quadruplex structure in the presence of specific metal ions. Here, circular dichroism, UV-vis absorption, fluorescence, and molecular dynamics simulation studies revealed that insulin-binding aptamer (IBA) could form an intramolecular G-quadruplex structure after binding K(+). Circular dichroism (CD) spectra demonstrated that IBA could fold into a parallel G-quadruplex with a strong positive peak at 263 nm.