title: Drug-protein binding mechanism of juglone for early pharmacokinetic profiling: Insights from ultrafiltration, multi-spectroscopic and molecular docking methods.
abstract: Juglone (JL), as one of the major bioactive components present in the bark of Juglans mandshruica Maxim, exhibits versatile bioactivities, especially anti-cancer activity. To better understand the pharmacokinetic properties of juglone, the protein binding rate of juglone was determined by ultrafiltration method, and the binding affinity and mechanism between JL and human serum albumin (HSA) was investigated in vitro through multi-spectroscopic, thermodynamic, and molecular modeling methods. The binding degree of JL was measured more than 99.0% which suggested that JL had high binding ability to serum albumin. Fluorescence data showed that juglone quench the intrinsic fluorescence of HSA upon forming the JL-HSA nonfluorescent complex at 1:1 stoichiometric proportion, and the complex formation had a high affinity of 104L·mol-1. Meanwhile, the site marker competitive experiments and the thermodynamic parameters (ΔG=-26.08 kJ·mol-1, ΔH=-16.34 kJ·mol-1, ΔS=32.69 J·mol-1·K-1) indicated that juglone could spontaneously bound to the site I (subdomain IIA) of HAS through hydrophobic and hydrogen bonding interactions. As further revealed by the synchronous fluorescence, three-dimensional fluorescence, Fourier transform infrared (FT-IR) and circular dichroism (CD) spectroscopy, JL could cause conformational and structural alterations of HSA. Additionally, molecular docking was employed to further define the specific binding site and the result was in accordance with the conclusion of experimental analysis. The present work provided reasonable models helping us further understand the pharmacokinetics, pharmacological and toxic effects of JL in vivo and supplied an important insight for the applications of JL in the clinical research.
authors.affiliation: School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, Liaoning Province, 110016, PR China.
authors.forename: Pan
authors.initials: P
authors.lastname: Zhao
authors.affiliation: School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, Liaoning Province, 110016, PR China; School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang, Liaoning Province 110016, PR China.
authors.forename: Guihua
authors.initials: G
authors.lastname: Gao
authors.affiliation: School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, Liaoning Province, 110016, PR China.
authors.forename: Lianjun
authors.initials: L
authors.lastname: Zhang
authors.affiliation: School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, Liaoning Province, 110016, PR China.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Cai
authors.affiliation: School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, Liaoning Province, 110016, PR China.
authors.forename: Nan
authors.initials: N
authors.lastname: Lu
authors.affiliation: School of Traditional Chinese Medicine, Shenyang Pharmaceutical University, Shenyang, Liaoning Province, 110016, PR China.
authors.forename: Li
authors.initials: L
authors.lastname: Cheng
authors.affiliation: School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, Liaoning Province, 110016, PR China.
authors.forename: Shuaikang
authors.initials: S
authors.lastname: Li
authors.affiliation: School of Pharmacy, Jining Medical College, Rizhao, Shandong Province, 272826, PR China. Electronic address: houxiaohong_syphu@163.com.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Hou
mesh_terms: D001665:Binding Sites; D002942:Circular Dichroism; D006801:Humans; D008958:Models, Molecular; D062105:Molecular Docking Simulation; D009285:Naphthoquinones / Q000032:analysis*; D011485:Protein Binding; D012709:Serum Albumin; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics; D014462:Ultrafiltration
chemical_list: D009285:Naphthoquinones; D012709:Serum Albumin; C005134:juglone
keywords: HSA-juglone complex; Human serum albumin; Juglone; Molecular modeling; Multi-spectroscopic