Molecular recognition of bio-active flavonoids quercetin and rutin by bovine hemoglobin: an overview of the binding mechanism, thermodynamics and structural aspects through multi-spectroscopic and molecular dynamics simulation studies

Abstract

The binding of two bio-active flavonoids, quercetin and rutin, with bovine hemoglobin (BHb) was investigated by multi-spectroscopic and computational (molecular docking and molecular dynamics simulation) studies. The two flavonoids were found to quench the intrinsic fluorescence of BHb through a static quenching mechanism. The binding constants at 288 K were observed to be (14.023 ± 0.73) × 104 M-1 and (7.848 ± 0.20) × 104 M-1, respectively for quercetin and rutin binding with BHb. Both rutin and quercetin were observed to increase the polarity around the Trp residues of BHb as indicated by synchronous and 3D spectral studies. No significant alterations in the secondary structural components of the protein were caused during the binding of the flavonoids as studied by CD and FTIR studies. The negative molar Gibbs free energies indicated the spontaneity of the interaction processes while the binding processes were characterized by a negative enthalpy change (ΔH) and a positive entropy change (ΔS). The possibility of energy transfer from the donor (BHb) to the acceptor molecules (flavonoids) was indicated by the FRET studies. According to the fluorescence studies, the flavonoids interact near to the β2-Trp37 residue of BHb. Excellent correlations with the experimental studies were observed from the molecular docking and molecular dynamics (MD) simulation studies. Further investigations established that these flavonoids are efficient in the inhibition of glucose mediated glycation of BHb.

Potential Targets of Actein Identified by Systems Chemical Biology Methods

“…All ligand parameters are generated using ANTECHAMBER module of the Amber14 with AM1‐BCC (Austin model 1‐bond charge correction) charges . The complex model was neutralized by adding Na + ions or Cl − ions and then solvated in 10 Å TIP3P octahedral boxes . Subsequently, the entire system was performed energy minimization by two steps.…”

“…[32] The complex model was neutralized by adding Na + ions or Cl À ions and then solvated in 10 Å TIP3P octahedral boxes. [33][34] Subsequently, the entire system was performed energy minimization by two steps. First, water molecules were minimized for 3,000 cycles with the complex constrained in 500 kcal mol À 1 · Å À 2 .…”

Selective Adsorption and Separation of Proteins by Ligand-Modified Nanofiber Fabric

“…In this research, bovine hemoglobin (BHb) and BSA were used as model proteins for selective separation. Hemoglobin is a carrier of oxygen and aids the transport of carbon dioxide, and BHb has more than 85% amino acid sequence homology with human hemoglobin [ 40 ]. Serum albumin maintains the osmotic pressure and pH of the blood and transports a wide variety of endogenous and exogenous compounds, and BSA displays approximately 76% sequence homology with human serum albumin [ 41 ].…”

Evaluation of Antioxidant Activity of Botto-Botto Leaf Fraction (Chromolaena Odorata L.) Using DPPH and ABTS Methods

“…Antioxidants are broadly defined as substances that inhibit the oxidation process from protecting cells from the dangers of free radicals that arise from body metabolism or other external factors. Chemically, natural antioxidants found in plants and foodstuffs are mainly derived from phenol-derived compounds such as flavonoids (quercetin) [4], [5], [6]. Chromolaena odorata (Family: Asteraceae) is synonymous with Eupatorium odoratum, a traditional medicinal plant widely used for its wound healing properties.…”