Binding site identification of anticancer drug gefitinib to HSA and DNA in the presence of five different probes

Abstract

This study was carried out to evaluate the binding interaction of gefitinib (GEF) with human serum albumin (HSA) and calf thymus DNA (ct-DNA) using fluorescence, UV-Visible, zeta potential measurements and molecular docking methods in order to understand its pharmacokinetic mechanism. By increasing the temperature, a steady decrease in Stern-Volmer quenching constants was observed for HSA binding properties; this indicates a static type of fluorescence quenching. Negative values were calculated for Gibbs free energy (ΔG), enthalpy (ΔH), and entropy (ΔS) changes, indicating that the reaction is spontaneous and enthalpy-driven. Probe competitive experimental results showed that GEF contains the same binding site as warfarin and are consistent with modeling results. The zeta potential of the HSA increased with increasing GEF, which represents the presence of electrostatic interactions in the system. DNA binding properties were investigated in the presence of three probes. The experimental results showed that by increasing GEF to DNA-AO (acridine-orange) and DNA-MB (methylene-blue) system, the fluorescence intensity and absorbance spectra had no considerable change. Furthermore, with the addition of GEF to DNA, the zeta potential decreased gradually, indicating that the hydrophobic interaction between the GEF and the bases of DNA is the major factor. Thus, GEF can bind to DNA via a groove binding mode. It was also found that GEF entered into the minor groove in the A-T rich region of DNA fragment and bind via van der-Waals forces and three H-bond with double strands of DNA. This is in good agreement with experimental results.

Synthesis of novel gefitinib‐based derivatives and their anticancer activity

“…Small molecules interacting with DNA can be categorized as an intercalator (ligand) and groove (DNA) binders. Studies identified that gefitinib targets the EGFR receptor which is protein in nature, but it also interacts with DNA that too specifically at A‐T region of the DNA . So to check the DNA interaction properties of newly synthesized compounds absorption titrations with calf thymus (CT) DNA was piloted which is a universally used method.…”

Deciphering binding affinity, energetics, and base specificity of plant alkaloid Harmane with AT and GC hairpin duplex DNA

“…They are recognized as sensitive probes for observing DNA structure, providing affinity for site-specificity in molecular biology and yielding important properties for drug design and therapeutic potential in controlling the gene expression. [34][35][36][37][38][39][40][41][42][43] The interaction of biological entities such as ribonucleic acid (RNA), deoxyribonucleic acid (DNA), and protein with the ligand is a prominent area of exploration in developing biomedical significance. [39,[44][45][46][47][48][49][50] DNA acts as an important part of storing the genetic information that is the potential therapeutic target in cancer and various other diseases.…”

Effects of crocin in reducing DNA damage, inflammation, and oxidative stress in multiple sclerosis patients: A double‐blind, randomized, and placebo‐controlled trial

“…The oxidative stress caused by these free radicals, such as reactive oxygen species (ROS) and reactive nitrogen species, as toxic reagents to nerve cells, destroys and disrupts their function and plays a key role in the pathological processes of several neurological disorders, such as MS and Alzheimer's disease . On the other hand, cells, by employing antioxidant machinery, could protect themselves against ROS‐induced damage and return the overall ROS levels to the equilibrium . In various pathological conditions, however, alterations in the ROS balance, due to either decreased antioxidant protection or an increase in ROS generation, result in the subsequent damage to the macromolecules comprising deoxyribonucleic acid (DNA), proteins, and lipids .…”