Binding interaction of atorvastatin with bovine serum albumin: Spectroscopic methods and molecular docking.

The interaction of atorvastatin with bovine serum albumin (BSA) was investigated using multi-spectroscopic methods and molecular docking technique for providing important insight into further elucidating the store and transport process of atorvastatin in the body and the mechanism of action and pharmacokinetics. The experimental results revealed that the fluorescence quenching mechanism of BSA induced atorvastatin was a combined dynamic and static quenching. The binding constant and number of binding site of atorvastatin with BSA under simulated physiological conditions (pH=7.4) were 1.41 × 10(5) M(-1) and about 1 at 310K, respectively. The values of the enthalpic change (ΔH(0)), entropic change (ΔS(0)) and Gibbs free energy (ΔG(0)) in the binding process of atorvastatin with BSA at 310K were negative, suggesting that the binding process of atorvastatin and BSA was spontaneous and the main interaction forces were van der Waals force and hydrogen bonding interaction. Moreover, atorvastatin was bound into the subdomain IIA (site I) of BSA, resulting in a slight change of the conformation of BSA.

Combined spectroscopies and molecular docking approach to characterizing the binding interaction between lisinopril and bovine serum albumin.

To further understand the mode of action and pharmacokinetics of lisinopril, the binding interaction of lisinopril with bovine serum albumin (BSA) under imitated physiological conditions (pH 7.4) was investigated using fluorescence emission spectroscopy, synchronous fluorescence spectroscopy, Fourier transform infrared spectroscopy (FTIR), circular dichroism (CD) and molecular docking methods. The results showed that the fluorescence quenching of BSA near 338 nm resulted from the formation of a lisinopril-BSA complex. The number of binding sites (n) for lisinopril binding on subdomain IIIA (site II) of BSA and the binding constant were ~ 1 and 2.04 × 10(4) M(-1), respectively, at 310 K. The binding of lisinopril to BSA induced a slight change in the conformation of BSA, which retained its α-helical structure. However, the binding of lisinopril with BSA was spontaneous and the main interaction forces involved were van der Waal's force and hydrogen bonding interaction as shown by the negative values of ΔG(0), ΔH(0) and ΔS(0) for the binding of lisinopril with BSA. It was concluded from the molecular docking results that the flexibility of lisinopril also played an important role in increasing the stability of the lisinopril-BSA complex.

Binding interaction of sorafenib with bovine serum albumin: Spectroscopic methodologies and molecular docking.

The binding interaction of sorafenib with bovine serum albumin (BSA) was studied using fluorescence, circular dichrosim (CD) and molecular docking methods. The results revealed that there was a static quenching of BSA induced by sorafenib due to the formation of sorafenib-BSA complex. The binding constant and number of binding site of sorafenib with BSA under simulated physiological condition (pH=7.4) were 6.8×10(4) M(-1) and 1 at 310 K, respectively. Base on the sign and magnitude of the enthalpy and entropy changes (ΔH(0)=-72.2 kJ mol(-1) and ΔS(0)=-140.4J mol(-1) K(-1)) and the results of molecular docking, it could be suggested that the binding process of sorafenib and BSA was spontaneous and the main interaction forces of sorafenib with BSA were van der Waals force and hydrogen bonding interaction. From the results of site marker competitive experiments and molecular docking, it could be deduced that sorafenib was inserted into the subdomain IIA (site I) of BSA and leads to a slight change of the conformation of BSA. And, the significant change of conformation of sorafenib occurred in the binding process with BSA to increase the stability of the sorafenib-BSA system, implying that the flexibility of sorafenib played an important role in the binding process.

Binding interaction between sorafenib and calf thymus DNA: spectroscopic methodology, viscosity measurement and molecular docking.

The binding interaction of sorafenib with calf thymus DNA (ct-DNA) was studied using UV-vis absorption spectroscopy, fluorescence emission spectroscopy, circular dichroism (CD), viscosity measurement and molecular docking methods. The experimental results revealed that there was obvious binding interaction between sorafenib and ct-DNA. The binding constant (Kb) of sorafenib with ct-DNA was 5.6×10(3) M(-1) at 298 K. The enthalpy and entropy changes (ΔH(0) and ΔS(0)) in the binding process of sorafenib with ct-DNA were -27.66 KJ mol(-1) and -21.02 J mol(-1) K(-1), respectively, indicating that the main binding interaction forces were van der Waals force and hydrogen bonding. The docking results suggested that sorafenib preferred to bind on the minor groove of A-T rich DNA and the binding site of sorafenib was 4 base pairs long. The conformation change of sorafenib in the sorafenib-DNA complex was obviously observed and the change was close relation with the structure of DNA, implying that the flexibility of sorafenib molecule played an important role in the formation of the stable sorafenib-ct-DNA complex.

A combined spectroscopic and molecular docking approach to characterize binding interaction of megestrol acetate with bovine serum albumin.

The binding interactions between megestrol acetate (MA) and bovine serum albumin (BSA) under simulated physiological conditions (pH 7.4) were investigated by fluorescence spectroscopy, circular dichroism and molecular modeling. The results revealed that the intrinsic fluorescence of BSA was quenched by MA due to formation of the MA-BSA complex, which was rationalized in terms of a static quenching procedure. The binding constant (Kb ) and number of binding sites (n) for MA binding to BSA were 2.8 × 10(5) L/mol at 310 K and about 1 respectively. However, the binding of MA with BSA was a spontaneous process due to the negative ∆G(0) in the binding process. The enthalpy change (∆H(0) ) and entropy change (∆S(0) ) were - 124.0 kJ/mol and -295.6 J/mol per K, respectively, indicating that the major interaction forces in the binding process of MA with BSA were van der Waals forces and hydrogen bonding. Based on the results of spectroscopic and molecular docking experiments, it can be deduced that MA inserts into the hydrophobic pocket located in subdomain IIIA (site II) of BSA. The binding of MA to BSA leads to a slight change in conformation of BSA but the BSA retained its secondary structure, while conformation of the MA has significant change after forming MA-BSA complex, suggesting that flexibility of the MA molecule supports the binding interaction of BSA with MA.

Characterization of intermolecular interaction between cyanidin-3-glucoside and bovine serum albumin: spectroscopic and molecular docking methods.

The intermolecular interaction between cyanidin-3-glucoside (Cy-3-G) and bovine serum albumin (BSA) was investigated using fluorescence, circular dichroism and molecular docking methods. The experimental results revealed that the fluorescence quenching of BSA at 338 nm by Cy-3-G resulted from the formation of Cy-3-G-BSA complex. The number of binding sites (n) for Cy-3-G binding on BSA was approximately equal to 1. The experimental and molecular docking results revealed that after binding Cy-3-G to BSA, Cy-3-G is closer to the Tyr residue than the Trp residue, the secondary structure of BSA almost not change, the binding process of Cy-3-G with BSA is spontaneous, and Cy-3-G can be inserted into the hydrophobic cavity of BSA (site II') in the binding process of Cy-3-G with BSA. Moreover, based on the sign and magnitude of the enthalpy and entropy changes (ΔH(0) = - 29.64 kcal/mol and ΔS(0) = - 69.51 cal/mol K) and the molecular docking results, it can be suggested that the main interaction forces of Cy-3-G with BSA are Van der Waals and hydrogen bonding interactions.

Intermolecular interaction of prednisolone with bovine serum albumin: spectroscopic and molecular docking methods.

The intermolecular interaction of prednisolone with bovine serum albumin (BSA) was studied using fluorescence, circular dichroism (CD) and molecular docking methods. The experimental results showed that the fluorescence quenching of the BSA at 338 nm by prednisolone resulted from the formation of prednisolone-BSA complex. The number of binding sites (n) for prednisolone binding on BSA was approximately equal to 1. Base on the sign and magnitude of the enthalpy and entropy changes (ΔH(0)=-149.6 kJ mol(-1) and ΔS(0)=-370.7 J mol(-1)K(-1)) and the results of molecular docking, it could be suggested that the interaction forces were mainly Van der Waals and hydrogen bonding interactions. Moreover, in the binding process of BSA with prednisolone, prednisolone molecule can be inserted into the hydrophobic cavity of subdomain IIIA (site II) of BSA. The distance between prednisolone and Trp residue of BSA was calculated as 2.264 nm according to Forster's non-radiative energy transfer theory.