He Wen-ying, Chen Hui-juan, Sheng Fen-ling, Yao Xiao-jun
Department of Chemistry, Hainan Normal University, Haikou, Hainan 571158, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2009 Oct 1;74(2):427-33. doi: 10.1016/j.saa.2009.06.044. Epub 2009 Jun 26.
BAFP (2,6-bis[4-(4-amino-2-trifluoromethylphenoxy)benzoyl] pyridine), a synthesized polyimide compound, was exploited for the first time to analyze its interaction with human serum albumin (HSA) by molecular modeling, fluorescence and Fourier transform infrared attenuated total reflection spectroscopy (FTIR ATR) with drug concentrations of 3.3 x 10(-6) to 3.0 x 10(-5) mol L(-1). Molecular docking was performed to reveal the possible binding mode. The results suggested that BAFP can strongly bind to human serum albumin (HSA) and the primary binding site of BAFP is located in site II of HSA, which is supported by the results from the competitive experiment. The binding constants for the interaction of BAFP with HSA have been evaluated from relevant fluorescence data at different temperatures (296, 303, 310 and 308 K). The alterations of the protein secondary structure in the presence of BAFP in aqueous solution were quantitatively calculated by the evidences from FTIR ATR spectroscopes. The binding process was exothermic and spontaneous, as indicated by the thermodynamic analyses, and the major part of the binding energy is hydrophobic interaction, which is also in good agreement with the results of molecule modeling study. The enthalpy change DeltaH(0), the free energy change DeltaG(0) and the entropy change DeltaS(0) of 296 K were calculated to be -7.75, -27.68 kJ mol(-1) and 67.33 J mol(-1) K(-1), respectively.
BAFP（2,6 - 双[4 - （4 - 氨基 - 2 - 三氟甲基苯氧基）苯甲酰基]吡啶）是一种合成的聚酰亚胺化合物，首次通过分子模拟、荧光和傅里叶变换红外衰减全反射光谱（FTIR ATR）对其与人类血清白蛋白（HSA）在3.3×10⁻⁶至3.0×10⁻⁵mol L⁻¹药物浓度下的相互作用进行分析。进行分子对接以揭示可能的结合模式。结果表明BAFP能与人类血清白蛋白（HSA）强烈结合，且BAFP的主要结合位点位于HSA的位点II，这一结果得到了竞争实验的支持。通过不同温度（296、303、310和308K）下的相关荧光数据评估了BAFP与HSA相互作用的结合常数。利用FTIR ATR光谱仪的证据定量计算了水溶液中存在BAFP时蛋白质二级结构的变化。热力学分析表明结合过程是放热且自发的，结合能的主要部分是疏水相互作用，这也与分子模拟研究结果高度一致。296K时的焓变ΔH⁰、自由能变ΔG⁰和熵变ΔS⁰分别计算为 - 7.75、 - 27.68kJ mol⁻¹和67.33J mol⁻¹ K⁻¹。
