Spectroscopy and Spectral Analysis, Volume. 34, Issue 5, 1343(2014)
Study on the Interaction of Doxycycline with Human Serum Albumin
The present study was designed to investigate the interaction of doxycycline (DC) with human serum albumin (HSA) by the inner filter effects, displacement experiments and molecular docking methods, based on classic multi-spectroscopy. With fluorescence quenching method at 298 and 310 K, the binding constants Ka were determined to be 2.73×105 and 0.74×105 L·mol-1, respectively, and there was one binding site between DC and HSA, indicating that the binding of DC to HSA was strong, and the quenching mechanism was a static quenching. The thermodynamic parameters (enthalpy change, ΔH and enthropy change, ΔS) were calculated to be -83.55 kJ·mol-1 and -176.31 J·mol-1·K-1 via the Vant’ Hoff equation, which indicated that the interaction of DC with HSA was driven mainly by hydrogen bonding and van der Waals forces. Based on the Fster’s theory of non-radiation energy transfer, the specific binding distance between Trp-214 (acceptor) and DC (donor) was 4.98 nm, which was similar to the result confirmed by molecular docking. Through displacement experiments, sub-domain IIA of HSA was assigned to possess the high-affinity binding site of DC. Three-dimensional fluorescence spectra indicated that the binding of DC to HSA induced the conformation change of HSA and increased the disclosure of some part of hydrophobic regions that had been buried before. The results of FTIR spectroscopy showed that DC bound to HSA led to the slight unfolding of the polypeptide chain of HSA. Furthermore, the binding details between DC and HSA were further confirmed by molecular docking methods, which revealed that DC was bound at sub-domain IIA through multiple interactions, such as hydrophobic effect, polar forces and π-π interactions. The experimental results provide theoretical basis and reliable data for the study of the interaction between small drug molecule and human serum albumin.
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HU Tao-ying, CHEN Lin, LIU Ying. Study on the Interaction of Doxycycline with Human Serum Albumin[J]. Spectroscopy and Spectral Analysis, 2014, 34(5): 1343
Received: Oct. 28, 2013
Accepted: --
Published Online: May. 6, 2014
The Author Email: Tao-ying HU (hty0945020@163.com)