title: In vitro study on binding interaction of quinapril with bovine serum albumin (BSA) using multi-spectroscopic and molecular docking methods.
abstract: The binding interaction between quinapril (QNPL) and bovine serum albumin (BSA) in vitro has been investigated using UV absorption spectroscopy, steady-state fluorescence spectroscopic, synchronous fluorescence spectroscopy, 3D fluorescence spectroscopy, Fourier transform infrared spectroscopy, circular dichroism, and molecular docking methods for obtaining the binding information of QNPL with BSA. The experimental results confirm that the quenching mechanism of the intrinsic fluorescence of BSA induced by QNPL is static quenching based on the decrease in the quenching constants of BSA in the presence of QNPL with the increase in temperature and the quenching rates of BSA larger than 1010L mol-1s-1, indicating forming QNPL-BSA complex through the intermolecular binding interaction. The binding constant for the QNPL-BSA complex is in the order of 105M-1, indicating there is stronger binding interaction of QNPL with BSA. The analysis of thermodynamic parameters together with molecular docking study reveal that the main binding forces in the binding process of QNPL with BSA are van der Waal's forces and hydrogen bonding interaction. And, the binding interaction of BSA with QNPL is an enthalpy-driven process. Based on Förster resonance energy transfer, the binding distance between QNPL and BSA is calculated to be 2.76 nm. The results of the competitive binding experiments and molecular docking confirm that QNPL binds to sub-domain IIA (site I) of BSA. It is confirmed there is a slight change in the conformation of BSA after binding QNPL, but BSA still retains its secondary structure α-helicity.
authors.affiliation: a College of Pharmaceutical Science , Zhejiang University of Technology , Hangzhou 310032 , China.|b State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology , Zhejiang University of Technology , Hangzhou 310032 , China.
authors.forename: Jie-Hua
authors.identifier: http://orcid.org/0000-0002-9807-5654
authors.initials: JH
authors.lastname: Shi
authors.affiliation: a College of Pharmaceutical Science , Zhejiang University of Technology , Hangzhou 310032 , China.
authors.forename: Dong-Qi
authors.initials: DQ
authors.lastname: Pan
authors.affiliation: a College of Pharmaceutical Science , Zhejiang University of Technology , Hangzhou 310032 , China.
authors.forename: Min
authors.initials: M
authors.lastname: Jiang
authors.affiliation: a College of Pharmaceutical Science , Zhejiang University of Technology , Hangzhou 310032 , China.
authors.forename: Ting-Ting
authors.initials: TT
authors.lastname: Liu
authors.affiliation: a College of Pharmaceutical Science , Zhejiang University of Technology , Hangzhou 310032 , China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
mesh_terms: D000818:Animals; D000959:Antihypertensive Agents / Q000737:chemistry*; D001665:Binding Sites; D002417:Cattle; D018360:Crystallography, X-Ray; D031541:Fluorescence Resonance Energy Transfer; D006860:Hydrogen Bonding; D007700:Kinetics; D062105:Molecular Docking Simulation; D011485:Protein Binding; D000072756:Protein Conformation, alpha-Helical; D054730:Protein Interaction Domains and Motifs; D000077583:Quinapril; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013696:Temperature; D044005:Tetrahydroisoquinolines / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D000959:Antihypertensive Agents; D044005:Tetrahydroisoquinolines; D012710:Serum Albumin, Bovine; D000077583:Quinapril
keywords: bovine serum albumin; interaction; molecular docking; quinapril; spectroscopy