title: 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 (Kb) were obtained by fluorescence quenching, and results show that the HSA-EH interaction revealed a static mode of quenching with binding constant Kb≈ 104reflecting 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.
authors.affiliation: Department of Medical Biotechnology, YeungNam University , 280 Daehak-ro, Gyeongsan, Gyeongbuk-38541, Republic of Korea.
authors.forename: Gulam
authors.initials: G
authors.lastname: Rabbani
authors.affiliation: Department of Medical Biotechnology, YeungNam University , 280 Daehak-ro, Gyeongsan, Gyeongbuk-38541, Republic of Korea.
authors.forename: Mohammad Hassan
authors.initials: MH
authors.lastname: Baig
authors.affiliation: Department of Medical Biotechnology, YeungNam University , 280 Daehak-ro, Gyeongsan, Gyeongbuk-38541, Republic of Korea.
authors.forename: Eun Ju
authors.initials: EJ
authors.lastname: Lee
authors.affiliation: Korean Medicine (KM) Application Center, Korea Institute of Oriental Medicine (KIOM) , Donggu, Daegu-41062, Republic of Korea.
authors.forename: Won-Kyung
authors.initials: WK
authors.lastname: Cho
authors.affiliation: Korean Medicine (KM) Application Center, Korea Institute of Oriental Medicine (KIOM) , Donggu, Daegu-41062, Republic of Korea.
authors.forename: Jin Yeul
authors.initials: JY
authors.lastname: Ma
authors.affiliation: Department of Medical Biotechnology, YeungNam University , 280 Daehak-ro, Gyeongsan, Gyeongbuk-38541, Republic of Korea.
authors.forename: Inho
authors.identifier: 0000-0002-5293-8231
authors.initials: I
authors.lastname: Choi
mesh_terms: D002151:Calorimetry / Q000379:methods*; D002942:Circular Dichroism; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D062105:Molecular Docking Simulation; D011427:Propiophenones / Q000737:chemistry*; D000075462:Serum Albumin, Human / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics
chemical_list: D011427:Propiophenones; C030848:eperisone; D000075462:Serum Albumin, Human
keywords: circular dichroism; differential scanning calorimetry; eperisone hydrochloride; esterase-like activity; human serum albumin; isothermal titration calorimetry; molecular docking; muscle relaxant