Bioorganic & Medicinal Chemistry
Volume 12, Issue 2, 15 January 2004, Pages 469-474
doi:10.1016/j.bmc.2003.10.030
Copyright © 2003 Elsevier Ltd. All rights reserved.
Interaction of isofraxidin with human serum albumin
Jiaqin Liua, b, Jianniao Tiana, Xuan Tiana, Zhide Hu, , a and Xingguo Chena
a Department of Chemistry, Lanzhou University, Lanzhou 730000, China
b Mianyang Teacher's College, Mianyang 621000, China
Received 5 August 2003; revised 10 October 2003; accepted 11 October 2003. ; Available online 9 December 2003.
Abstract
This study was designed to examine the interaction of isofraxidin with human serum albumin (HSA) under physiological conditions with drug concentrations in the range of 3.3×10−6 mol L−1–3.0×10−5 mol L−1 and HSA concentration at 1.5×10−6 mol L−1.
Fluorescence quenching methods in combination with Fourier transform infrared (FT-IR) spectroscopy and circular dichroism (CD) spectroscopy were used to determine the drug-binding mode, the binding constant and the protein structure changes in the presence of isofraxidin in aqueous solution.
Spectroscopic evidence showed that the interaction results in one type of isofraxidin–HSA complex with binding constants of 4.1266×105 L mol−1, 3.8612×105 L mol−1, 3.5063×105 L mol−1, 3.1241×105 L mol−1 at 296 K, 303 K, 310 K, 318 K, respectively. The thermodynamic parameters, enthalpy change (ΔH) and entropy change (ΔS) were calculated to be −10.08 kJ mol−1 and 73.57 J mol−1 K−1 according to van't Hoff equation, which indicated that hydrophobic interaction played a main role in the binding of isofraxidin to HSA.
The experiment results are nearly in accordance with the calculation results obtained by Silicon Graphics Ocatane2 workstation.
Graphical Abstract
We studied firstly the binding of isofraxidin to human serum albumin (HSA) under physiological conditions utilizing fluorescence method in combination with FT-IR and CD technique.
Author Keywords: Isofraxidin; Human serum albumin; Binding; Fluorescence quenching; FT-IR spectroscopy; CD spectroscopy
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