多西环素与人血清白蛋白相互作用的研究  

Study on the Interaction of Doxycycline with Human Serum Albumin

作　　者：胡涛英 陈琳[2] 刘颖[1,3] 

机构地区：[1]中央民族大学生命与环境科学学院,北京100081 [2]广东药学院药科学院,广东广州510006 [3]中央民族大学北京市食品环境与健康工程技术研究中心,北京100081

出　　处：《光谱学与光谱分析》2014年第5期1343-1347,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(21177163);高等学校学科创新引智计划项目(B08044);中央民族大学"985工程"项目(MUC98504-14;MUC98507-08);中央民族大学"211工程"项目(MUC02121103);中央高校基本科研业务费专项资金项目(0910KYZY45);中央民族大学北京市食品环境与健康工程技术研究中心项目资助

摘　　要：将经典光谱法与内滤光校正、取代实验和分子对接等技术相结合,较全面地研究了多西环素(DC)与人血清白蛋白(HSA)之间的相互作用。通过荧光猝灭实验测得在298和310K时,DC与HSA的结合常数分别为2.73×105和0.74×105 L·mol-1,二者有一个结合位点,表明DC与HSA间具有较强的结合作用,属于静态猝灭。根据Vant’Hoff公式计算的热力学参数(ΔH=-83.55kJ·mol-1,ΔS=-176.31J·mol-1·K-1)表明,两者间主要作用力为氢键和范德华力。根据Fster能量转移定律求得DC与HSA的Trp-214之间的结合距离为4.98nm。取代反应结果表明,DC键合在HSA的亚域IIA内。三维荧光光谱结果显示,DC使HSA疏水性增加,改变了HSA的构象。DC与HSA作用前后红外光谱二级结构的定量分析结果表明,DC能使HSA结构松散。分子对接技术进一步表明DC通过氢键和范德华力等键合在HSA的亚域IIA疏水腔中,结合距离与光谱法计算结果相近。实验结果为研究药物小分子与人血清白蛋白的相互作用提供了理论依据和可靠数据。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 en-thropy 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 F？ster’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 .

关 键 词：光谱法 分子对接 相互作用 HSA DC 

分 类 号：O657.3[理学—分析化学]