title: Spectroscopic studies on the interaction between tetrandrine and two serum albumins by chemometrics methods.
abstract: The binding interactions of tetrandrine (TETD) with bovine serum albumin (BSA) and human serum albumin (HSA) have been investigated by spectroscopic methods. These experimental data were further analyzed using multivariate curve resolution-alternating least squares (MCR-ALS) method, and the concentration profiles and pure spectra for three species (BSA/HSA, TETD and TETD-BSA/HSA) existed in the interaction procedure, as well as, the apparent equilibrium constants Kapp were evaluated. The binding sites number n and the binding constants K were obtained at various temperatures. The binding distance between TETD and BSA/HSA was 1.455/1.451nm. The site markers competitive experiments indicated that TETD primarily bound to the tryptophan residue of BSA/HSA within site I. The thermodynamic parameters (ΔG, ΔH and ΔS) calculated on the basis of different temperatures revealed that the binding of TETD-BSA was mainly depended on the hydrophobic interaction strongly and electrostatic interaction, and yet the binding of TETD-HSA was strongly relied on the hydrophobic interaction. The results of synchronous fluorescence, 3D fluorescence and FT-IR spectra show that the conformation of proteins has altered in the presence of TETD. In addition, the effect of some common ions on the binding constants between TETD and proteins were also discussed.
authors.affiliation: Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, China West Normal University, Nanchong 637002, China. ncczj1112@126.com
authors.forename: Zhengjun
authors.initials: Z
authors.lastname: Cheng
authors.forename: Rong
authors.initials: R
authors.lastname: Liu
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Jiang
mesh_terms: D000818:Animals; D044182:Benzylisoquinolines / Q000737:chemistry / Q000378:metabolism*; D002417:Cattle; D004735:Energy Transfer; D006801:Humans; D007477:Ions; D007700:Kinetics; D016018:Least-Squares Analysis; D015999:Multivariate Analysis; D011485:Protein Binding; D011487:Protein Conformation; D012709:Serum Albumin / Q000378:metabolism*; D012710:Serum Albumin, Bovine / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013057:Spectrum Analysis / Q000379:methods*; D013696:Temperature; D013816:Thermodynamics
chemical_list: D044182:Benzylisoquinolines; D007477:Ions; D012709:Serum Albumin; D012710:Serum Albumin, Bovine; C009438:tetrandrine
keywords: Binding constants; Bovine serum albumin; Human serum albumin; Multivariate curve resolution-alternating least squares; Tetrandrine; Thermodynamic parameters