Premium
The interaction between cepharanthine and two serum albumins: multiple spectroscopic and chemometric investigations
Author(s) -
Cheng Zhengjun,
Liu Rong,
Jiang Xiaohui,
Xu Qianyong
Publication year - 2014
Publication title -
luminescence
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.428
H-Index - 45
eISSN - 1522-7243
pISSN - 1522-7235
DOI - 10.1002/bio.2576
Subject(s) - chemistry , circular dichroism , bovine serum albumin , binding constant , human serum albumin , analytical chemistry (journal) , tryptophan , quenching (fluorescence) , fluorescence , protein secondary structure , serum albumin , chromatography , binding site , crystallography , biochemistry , amino acid , physics , quantum mechanics
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 (Δ G , Δ H and Δ S ) 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. Copyright © 2013 John Wiley & Sons, Ltd.