Binding between Saikosaponin C and Human Serum Albumin by Fluorescence Spectroscopy and Molecular Docking
| Autor: | Qing-Xia Niu, Guo-Wu Liang, Dan-Yan Ye, Yicun Chen, Hong-Mei Wang |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
0301 basic medicine
Models Molecular Circular dichroism Protein Conformation Pharmaceutical Science 01 natural sciences Molecular Docking Simulation Analytical Chemistry Drug Discovery skin and connective tissue diseases Radix bupleuri biology integumentary system Chemistry saikosaponin C Circular Dichroism Human serum albumin Chemistry (miscellaneous) human serum albumin embryonic structures Molecular Medicine static quenching medicine.drug Protein Binding Stereochemistry Serum albumin molecular docking Chaihu 010402 general chemistry Fluorescence spectroscopy Article lcsh:QD241-441 03 medical and health sciences lcsh:Organic chemistry medicine Humans Physical and Theoretical Chemistry Binding site Oleanolic Acid Serum Albumin Quenching (fluorescence) Binding Sites Organic Chemistry Hydrogen Bonding Saponins Binding constant 0104 chemical sciences body regions Crystallography 030104 developmental biology Spectrometry Fluorescence Energy Transfer biology.protein |
| Zdroj: | Molecules Molecules, Vol 21, Iss 2, p 153 (2016) Molecules; Volume 21; Issue 2; Pages: 153 |
| ISSN: | 1420-3049 |
| Popis: | Saikosaponin C (SSC) is one of the major active constituents of dried Radix bupleuri root (Chaihu in Chinese) that has been widely used in China to treat a variety of conditions, such as liver disease, for many centuries. The binding of SSC to human serum albumin (HSA) was explored by fluorescence, circular dichroism (CD), UV-vis spectrophotometry, and molecular docking to understand both the pharmacology and the basis of the clinical use of SSC/Chaihu. SSC produced a concentration-dependent quenching effect on the intrinsic fluorescence of HSA, accompanied by a blue shift in the fluorescence spectra. The Stern-Volmer equation showed that this quenching was dominated by static quenching. The binding constant of SSC with HSA was 3.72 × 10³ and 2.99 × 10³ L·mol(-1) at 26 °C and 36 °C, respectively, with a single binding site on each SSC and HSA molecule. Site competitive experiments demonstrated that SSC bound to site I (subdomain IIA) and site II (subdomain IIIA) in HSA. Analysis of thermodynamic parameters indicated that hydrogen bonding and van der Waals forces were mostly responsible for SSC-HSA association. The energy transfer efficiency and binding distance between SSC and HSA was calculated to be 0.23 J and 2.61 nm at 26 °C, respectively. Synchronous fluorescence and CD measurements indicated that SSC affected HSA conformation in the SSC-HSA complex. Molecular docking supported the experimental findings in conformational changes, binding sites and binding forces, and revealed binding of SSC at the interface between subdomains IIA-IIB. |
| Databáze: | OpenAIRE |
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