Biophysical Study on the Interaction between Eperisone Hydrochloride and Human Serum Albumin Using Spectroscopic, Calorimetric, and Molecular Docking Analyses

Abstract

Eperisone hydrochloride (EH) is widely used as a muscle relaxant for patients with muscular contracture, low back pain, or spasticity. Human serum albumin (HSA) is a highly soluble negatively charged, endogenous and abundant plasma protein ascribed with the ligand binding and transport properties. The current study was undertaken to explore the interaction between EH and the serum transport protein, HSA. Study of the interaction between HSA and EH was carried by UV-vis, fluorescence quenching, circular dichroism (CD), Fourier transform infrared (FTIR) spectroscopy, Förster's resonance energy transfer, isothermal titration calorimetry and differential scanning calorimetry. Tryptophan fluorescence intensity of HSA was strongly quenched by EH. The binding constants (K) were obtained by fluorescence quenching, and results show that the HSA-EH interaction revealed a static mode of quenching with binding constant K ≈ 10 reflecting high affinity of EH for HSA. The negative ΔG° value for binding indicated that HSA-EH interaction was a spontaneous process. Thermodynamic analysis shows HSA-EH complex formation occurs primarily due to hydrophobic interactions, and hydrogen bonds were facilitated at the binding of EH. EH binding induces α-helix of HSA as obtained by far-UV CD and FTIR spectroscopy. In addition, the distance between EH (acceptor) and Trp residue of HSA (donor) was calculated 2.18 nm using Förster's resonance energy transfer theory. Furthermore, molecular docking results revealed EH binds with HSA, and binding site was positioned in Sudlow Site I of HSA (subdomain IIA). This work provides a useful experimental strategy for studying the interaction of myorelaxant with HSA, helping to understand the activity and mechanism of drug binding.

Interaction of coumarin triazole analogs to serum albumins: Spectroscopic analysis and molecular docking studies

“…Active binding sites of serum albumins were recognized using MetaPocket server. Docking was performed by PatchDock server and Hex 8.0.0 Cuda, while docking complexes were visualized by Discovery Studio 3.0 and ligplot+ . The criteria for selection of the indicated structures were based on PDB advance BLAST analysis, and the structures used in this study were those displaying maximum score and query cover in BLAST.…”

Insights into the interaction of potent antimicrobial chalcone triazole analogs with human serum albumin: spectroscopy and molecular docking approaches

“…35 The uorescence spectra were recorded at three temperatures (288, 298 and 308 K) in order to determine the mechanism of quenching. The uorescence quenching data were evaluated using the Stern-Volmer equation: 36 When the bimolecular quenching constant is greater than the diffusionlimited rate constant of the biomolecule, it results in static mechanism of uorescence quenching. 37 The Stern-Volmer plots of the titrations of HSA with CTs are depicted in Fig.…”

Investigating the Interaction of Nanodiamonds with Human Serum Albumin and Induced Cytotoxicity

“…e NDs solution does not show any obvious absorption peak between 300 nm and 800 nm. However, in the presence of NDs, the absorption of HSA increases and the absorption peak shifts from 280 nm to 275 nm, which probably resulted from the change in the polarity around the Trp residues [25]. To investigate the conformation of HSA, circular dichroism (CD) was performed to monitor the secondary structure of HSA in the presence of NDs.…”

“…K sv is the Stern-Volmer quenching constant, and k q is the apparent bimolecular quenching rate constant. τ 0 is the average lifetime of the protein without quencher, which is about 5.79 × 10 − 9 s for HSA [25].…”