title: The interaction between cepharanthine and two serum albumins: multiple spectroscopic and chemometric investigations.
abstract: The binding modes of cepharanthine (CEPT) with bovine serum albumin (BSA) and human serum albumin (HSA) have been established by reproducing physiological conditions, which is very important to understand the pharmacokinetics and toxicity of CEPT. These spectral data were further analyzed by the multivariate curve resolution-alternating least squares method. Moreover, the concentration profiles and pure spectra of three species (BSA/HSA, CEPT and CEPT-BSA/HSA) and the apparent equilibrium constants K(app) were evaluated. The experimental results showed that CEPT could quench the fluorescence intensity of BSA/HSA by a combined quenching (static and dynamic) procedure. The binding constant (K), the thermodynamic parameters (ΔG, ΔH and ΔS) and binding subdomain were measured, and indicated that CEPT could spontaneously bind to BSA/HSA on subdomain IIA through the hydrophobic interactions. The effect of CEPT on the secondary structure of proteins has been analyzed by circular dichroism, 3D fluorescence and Fourier transform infrared spectra. The binding distance between CEPT and tryptophan of BSA/HSA was 2.305/1.749 nm, which is based on the Förster resonance energy transfer theory.
authors.affiliation: Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, China West Normal University, Nanchong, 637002, China.
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
authors.forename: Qianyong
authors.initials: Q
authors.lastname: Xu
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry*; D044182:Benzylisoquinolines / Q000737:chemistry*; D002417:Cattle; D005453:Fluorescence; D031541:Fluorescence Resonance Energy Transfer; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D011485:Protein Binding; D017433:Protein Structure, Secondary; D012709:Serum Albumin / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013057:Spectrum Analysis / Q000295:instrumentation / Q000379:methods*; D013816:Thermodynamics; D052117:Benzodioxoles
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D044182:Benzylisoquinolines; D012709:Serum Albumin; D012710:Serum Albumin, Bovine; C006947:cepharanthine; D052117:Benzodioxoles
keywords: Bovine serum albumin; binding constants; cepharanthine; human serum albumin; multivariate curve resolution-alternating least squares