Investigation the interaction of Daphnin with human serum albumin using optical spectroscopy and molecular modeling methods.
The interaction between Daphnin with human serum albumin has been studied for the first time by spectroscopic methods including fluorescence quenching technology, circular dichroism (CD) spectroscopy and Fourier transform infrared (FT-IR) spectroscopy under simulative physiological conditions. The results of fluorescence titration revealed that Daphnin can quench the intrinsic fluorescence of HSA by static quenching and there is a single class of binding site on HSA. In addition, the studies of CD spectroscopy and FT-IR spectroscopy showed that the protein secondary structure changed with increases of α-helices at the drug to protein molar ratio of 2. Furthermore, the thermodynamic functions ΔH(0) and ΔS(0) for the reaction were calculated to be 11.626 kJ mol(-1) and 118.843 J mol(-1)K(-1) according to Van't Hoff equation. The thermodynamic parameters (ΔH(0) and ΔS(0)) and the molecular modeling study indicated that hydrophobic force played an important role to stabilize the Daphnin-HSA complex, and Daphnin could bind within the subdomain IIA of the HSA.
Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004, China. zhujinhua0528@163.com
Jinhua
J
Zhu
Liye
L
Wu
Qingyou
Q
Zhang
Xingguo
X
Chen
Xiuhua
X
Liu
D001665:Binding Sites; D002942:Circular Dichroism; D003374:Coumarins / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008958:Models, Molecular; D055620:Optical Phenomena; D011485:Protein Binding; D012709:Serum Albumin / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013057:Spectrum Analysis / Q000379:methods*; D013816:Thermodynamics
D003374:Coumarins; D012709:Serum Albumin; C030123:coumarin; C575582:daphnin