邻苯二甲酸二环己酯与牛血清白蛋白相互作用研究北大核心CSCD

本文利用光谱法和分子对接技术,研究邻苯二甲酸二环己酯(DCHP)与牛血清白蛋白(BSA)的相互作用机制。荧光光谱结果表明,DCHP可以诱导BSA的内源性荧光猝灭,且猝灭机制为静态猝灭;随着DCHP浓度增大,BSA最大发射波长发生蓝移。不同温度下的热力学常数表明,DCHP主要靠氢键和范德华力与BSA相结合;同时DCHP与BSA只有1个结合位点。位点实验结果显示DCHP与BSA在位点Ⅰ结合。同步荧光光谱、三维荧光和圆二色谱结果进一步证实DCHP改变了BSA的构象。通过分子对接技术模拟DCHP与BSA在分子水平上的相互作用机制,结果与光谱学研究结果一致。     

多光谱法结合分子模拟技术研究多西他赛与人血清白蛋白的作用

利用荧光光谱、紫外光谱、三维荧光光谱、红外光谱、圆二色谱和分子对接技术研究了多西他赛(DT)与人血清白蛋白(HSA)的相互作用机理,探讨了 7种辅酶对HSA及DT-HSA体系的影响.结果表明,DT对HSA的猝灭机制为静态猝灭且伴随非辐射能量的转移,二者通过疏水力、氢键和范德华力共同作用形成1∶1的配合物.HSA的主要结...     

光谱-分子模拟法分析杨梅素与人血清白蛋白的分子作用机制

在模拟生理条件下,用多种光谱法结合分子对接法测定了杨梅素(MY)与人血清白蛋白(HSA)的相互作用.研究结果表明,MY能够明显猝灭HSA的荧光,MY与HSA的相互作用为复合式静态结合过程,结合强度较强.热力学和分子对接结果表明,MY与HSA是自发结合的,维持MY与HSA的相互作用力主要是氢键和范德华力.能量转移结果表明...     

光谱法及分子模拟研究芹菜素与人血清白蛋白的相互作用

利用紫外光谱、荧光光谱、红外光谱、圆二色光谱及分子模型等技术,在生理pH条件下,研究了芹菜素与人血清白蛋白的相互作用,计算了结合常数和热力学参数。分子模型研究表明,芹菜素与人血清白蛋白在亚结构域ⅡA结合,二者间的主要作用为疏水作用和静电作用,这与荧光光谱所得结果基本一致。红外光谱、圆二色光谱及同步荧光光谱均显示芹菜素与人血清白蛋白结合后没有改变人血清白蛋白的二级结构。     

荧光光谱法结合分子对接研究邻苯二甲酸单环己酯与牛血清白蛋白的相互作用

通过荧光光谱、圆二色谱及计算机模拟技术研究了邻苯二甲酸单环己酯（MCHP）与牛血清白蛋白（BSA）的相互作用机制。结果表明：MCHP能够自发进入BSA的结合位点I,并引起BSA的内源荧光猝灭;BSA-MCHP复合物的稳定性随着温度上升而下降;除了氢键和范德华力,MCHP与BSA之间的Pi-Sigma、 Pi-Alkyl以及Alkyl作用力在结合过程中也发挥了重要作用;MCHP诱导BSA的二级结构发生改变,其中α-螺旋的含量从游离态的66.5%下降至复合态的59.0%;计算机模拟结果表明,BSA的Trp213和Arg198残基与MCHP的2个羰基上的氧原子形成2个氢键,并且Trp213与MCHP之间的相互作用是导致BSA荧光猝灭的重要因素。     

光谱法及分子对接研究邻苯二甲酸单乙基己基酯与人血清白蛋白的相互作用

通过荧光光谱法、紫外分光光度法以及分子对接技术探究邻苯二甲酸单乙基己基酯(MEHP)与人血清白蛋白(HSA)之间的相互作用及其作用机制。光谱学数据显示,MEHP诱导HSA内源荧光猝灭是因为两者间发生非辐射能量转移并形成稳定的复合物;不同温度下的热力学常数表明范德华力或氢键为MEHP与HSA结合的主要驱动力;三维荧光光谱结果证实MEHP改变了HSA的构象;同步荧光光谱和位点实验表明,MEHP在位点Ⅰ与HSA结合。根据光谱学的研究结果,采用分子对接技术模拟MEHP与HSA在分子水平上的相互作用机制,结果与光谱学研究结果一致。     

黄芩苷与人血清白蛋白的相互作用研究

利用紫外光谱、荧光光谱、傅立叶红外谱、圆二色谱及分子模型等技术,在生理pH条件下,研究了黄芩苷与人血清白蛋白(HSA)的相互作用,并计算了其结合常数和热力学参数.分子模型研究表明,黄芩苷与HSA在亚结构域ⅡA结合,二者间的作用主要为静电作用和疏水作用,与荧光光谱结果基本一致.红外光谱和圆二色谱显示黄芩苷与HSA结合后未...     

还原型辅酶烟酰胺腺嘌呤二核苷酸与人血清白蛋白相互作用的研究

运用荧光光谱、紫外光谱和计算机模拟分子对接等技术,研究了在模拟生理条件下还原型辅酶烟酰胺腺嘌呤二核苷酸(NADH)与人血清白蛋白(HSA)的作用方式及热力学特征。结果表明,NADH与人血清白蛋白的荧光猝灭机理属于静态猝灭;NADH与HSA在温度283K和310K时的结合常数和结合位点数分别为1.972×104 L.mol-1、0.9657和1.468×104 L.mol-1、0.9105,通过热力学计算得到反应的热力学参数;同步荧光光谱表明NADH使色氨酸残基的微环境亲水性增强;分子模型研究表明,二者通过疏水力、静电力和氢键共同作用结合。     

利福布汀与人血清白蛋白相互作用的光谱研究

用荧光光谱法和圆二色谱法研究了利福布汀(RB)与人血清白蛋白(HSA)的相互作用. 结果表明, RB与HSA之间的相互作用主要是疏水作用, 作用机制是静态猝灭与动态猝灭的结合. 其结合常数(Ka)在106数量级, 说明RB和HSA有很强的结合. 此外, 探讨了金属离子(Cu2+, Zn2+, Mg2+ 和Ca2+)对RB与HSA结合常数的影响. 同步荧光光谱和圆二色谱数据表明, RB可导致HSA的构象改变.     

防腐剂苯甲酸与人血清白蛋白相互作用

为研究食品防腐剂苯甲酸在人体内的转运和降解机制,在人体血液的生理条件下运用荧光光谱法和分子对接、分子动力学模拟和丙氨酸突变扫描等方法研究了苯甲酸与人血清白蛋白(Human Serum Albumin, HSA)相互作用机理。结果表明:苯甲酸和HSA的结合为静态猝灭过程,不同条件下结合常数K_A均大于1.0×10⁴ L/mol,结合位点数约为1,结合位点为Site II;根据Van′t Hoff方程和分子动力学模拟发现两者结合主要促进作用力是静电作用力,抑制力是极性溶剂化能,且是自由能降低的自发反应;分子对接结果显示复合物中苯甲酸与ARG186形成1个氢键,丙氨酸突变扫描计算显示ASP108、GLN425和GLV459是结合的关键氨基酸。     

Toxic Interaction between Dibutyl Phthalate and Human Serum Albumin: Spectroscopic and Molecular Modeling Investigations

Because of the widely usage of Dibutyl phthalate (DBP), its residue exist extensively in the environment and can enter human body, being potential harmful. Human serum albumin (HSA) is a major transporter for endogenous and exogenous compounds in vivo. The aim of this study was to examine the interaction of HSA with DBP through spectroscopic and molecular modeling methods. The experiments revealed that DBP binds to site I (subdomain IIA) of HSA mainly through hydrophobic interactions, illustrated by the calculated ΔH and ΔS. Furthermore, molecular docking was applied to define the specific binding sites, the results of which show that DBP mainly interacts with the positively charged amino acid residues LEU 219, PHE 223, LEU 234, LEU 238, ALA 258, LEU 260, and ILE 290 predominately through hydrophobic interactions, in accordance with the conclusion of thermodynamic analysis. The binding of DBP can cause conformational and some microenvironmental changes of HSA, revealed by UV‐vis absorption, synchronous fluorescence, and circular dichroism results. The accurate and full basic data in the work is beneficial to clarifying the binding mechanism of DBP with HSA in vivo and understanding its effect on protein function during the blood transportation process.     

光谱法与分子模拟对左旋紫草素和人血白蛋白键合作用的研究

采用荧光光谱法、紫外吸收光谱法和圆二色性光谱(CD)研究了模拟生理条件下左旋紫草素和人血清白蛋白(HSA)的相互作用,计算了反应的结合常数、结合位点数和热力学参数,并探讨了左旋紫草素对人血清白蛋白二级结构的影响.在温度为292、303、310和318 K时,根据Scatchard方程测得左旋紫草素和HSA的结合常数分别为3.118×10~6、0.249×10~6、0.112×10~6 和0.102×10~6 L·mol~(-1),结合位点数分别为1.308、1.094、1.026和1.018;焓变(ΔH)和熵变(ΔS)分别为-104.82 kJ·mol~(-1)、-238.18 J·mol~(-1)·K~(-1),左旋紫草素在人血清白蛋白上的结合位置与色氨酸残基间的距离为2.66 nm.分子模型研究表明,左旋紫草素与HSA在亚结构域ⅡA结合,二者间的作用力主要为疏水和氢键作用力.CD结果表明,左旋紫草素与HSA的键合使HSA中α-螺旋结构含量从55.80%降到52.31%.     

光谱法研究根皮苷与人血清白蛋白相互作用

在模拟生理条件下,采用荧光光谱、紫外光谱和同步荧光光谱法研究了根皮苷(Phlorizin)与人血清白蛋白(HSA)的相互作用。结果表明:根皮苷能使HSA发生内源荧光猝灭,属静态猝灭。在293、303 K和313 K下,根皮苷与HSA的结合常数分别为3.163 5×105、1.774 8×105、1.193 5×105L.mol-1,结合位点数n近似为1;热力学分析表明根皮苷与HSA间的结合力为氢键及范德华力;根据Frster非辐射能量转移理论求得二者结合距离为3.97 nm;同步荧光光谱表明根皮苷主要与HSA中的色氨酸残基发生相互作用,改变色氨酸周围的局部构象;金属离子的介入会影响根皮苷与HSA的结合能力。     

Interaction of Human Serum Albumin with Indomethacin: Spectroscopic and Molecular Modeling Studies

In this work, the interaction between indomethacin (IM) and human serum albumin (HSA) under simulative physiological conditions was investigated by the methods of fluorescence spectroscopy, circular dichroism (CD) spectroscopy, and molecular modeling. The experiment results showed that the fluorescence quenching of HSA by IM was a result of the formation of an IM–HSA complex and the corresponding association constants (K _a) between IM and HSA at four different temperatures were determined according to the modified Stern–Volmer equation. The resulting thermodynamic parameters ΔG, ΔH, and ΔS at different temperatures indicate that the hydrophobic force plays a major role for IM–HSA association, but hydrogen bonds also could not be excluded. A molecular modeling study further confirmed the binding mode and indicated that the binding of IM to HSA primarily takes place in sub-domain IIA (site I). The conformational investigation showed that the presence of IM decreased the α-helical content of HSA and induced slight unfolding of the polypeptides of protein, which confirmed that some microenvironmental and conformational changes occur for HSA molecules.     

Characterization of Gallic Acid Interaction with Human Serum Albumin by Spectral and Molecular Modeling Methods

The binding of drugs with human serum albumin(HSA)is a crucial factor influencing the distribution and bioactivity of drugs in the body.To understand the action mechanisms between gallic acid(GA,3,4,5-...     

Interaction Between Ginkgolic Acid and Human Serum Albumin by Spectroscopy and Molecular Modeling Methods

The interaction of ginkgolic acid (15:1, GA) with human serum albumin (HSA) was investigated by FT–IR, CD and fluorescence spectroscopic methods as well as molecular modeling. FT–IR and CD spectroscopic showed that complexation with the drug alters the protein’s conformation by a major reduction of α-helix from 54 % (free HSA) to 46–31 % (drug–complex), inducing a partial protein destabilization. Fluorescence emission spectra demonstrated that the fluorescence quenching of HSA by GA was by a static quenching process with binding constants on the order of 10⁵ L·mol^?1. The thermodynamic parameters (ΔH = ?28.26 kJ·mol^?1, ΔS = 11.55 J·mol^?1·K^?1) indicate that hydrophobic forces play a leading role in the formation of the GA–HSA complex. The ratio of GA and HSA in the complex is 1:1 and the binding distance between them was calculated as 2.2 nm based on the Förster theory, which indicates that the energy transfer from the tryptophan residue in HSA to GA occurs with high probability. On the other hand, molecular docking studies reveal that GA binds to Site II of HSA (sub-domain IIIA), and it also shows that several amino acids participate in drug–protein complexation, which is stabilized by H-bonding.     

Studies of the Interaction Between Ronidazole and Human Serum Albumin by Spectroscopic and Molecular Docking Methods

Ronidazole (RNZ) is widely used for the therapeutic treatment of farmed animals and is suspected of being a human carcinogen and mutagen. The interaction between RNZ and human serum albumin (HSA) was investigated systematically by fluorescence spectroscopy, synchronous fluorescence, three-dimensional fluorescence, CD spectroscopy, UV–vis absorption spectroscopy and a molecular docking study. The results indicate that the probable quenching mechanism of HSA by RNZ is dynamic quenching. The corresponding thermodynamic parameters, such as ΔH, ΔS and ΔG, etc., were calculated according to the van’t Hoff equation. The results indicate that the forces acting between RNZ and HSA are mainly hydrogen bonds and van der Waals forces. The conformational changes in the interaction were studied by synchronous fluorescence, CD spectroscopy and three-dimensional fluorescence spectra. The results reveal that the microenvironment and conformation of HSA has been changed. A molecular modeling study further confirmed the binding mode obtained by the experimental studies.     

土贝母皂苷II与人血清白蛋白相互作用机制的光谱研究

人血清白蛋白多种结合位点的存在使其成为许多药物可能的结合靶点. 土贝母皂苷具有广泛的生理和药理活性, 它与蛋白质相互作用机制的研究对于深入了解其药理药效具有重要的意义. 采用荧光光谱法研究了土贝母皂苷II (TBMSⅡ)与人血清白蛋白(HSA)之间的相互作用, 根据Stern-Volmer荧光淬灭方程计算得293, 298, 303, 308 K时TBMSⅡ与HSA相互作用的结合常数分别为1.002×10⁵, 0.701×10⁵, 0.514×10⁵, 0.411×10⁵ L•mol^－1. 由实验计算出热力学参数焓变ΔH为－44.829 kJ•mol^－1, 熵变ΔS为－57.497 J•mol^－1•K^－1, 表明分子间的氢键及疏水作用是TBMSⅡ-HSA复合物的主要作用力, 结合位点位于HSA的亚结构ⅡA, 这与分子模拟方法的结果相一致. 依据能量转移原理求得TBMSⅡ与HSA间的距离为4.95 nm|三维、同步荧光光谱及圆二色谱的结果表明TBMSⅡ的加入使HSA构象发生变化, α-螺旋结构有所下降.     

黄芩素和黄芩苷与人血清白蛋白相互作用的光谱研究

采用荧光光谱、紫外-可见光谱和表面增强拉曼光谱研究了黄芩素和黄芩苷与人血清白蛋白的相互作用, 得到了分子间的结合状态和吸附形态方面的信息. 通过比较黄芩素和黄芩苷的普通拉曼和表面增强拉曼光谱, 确立了黄芩素和黄芩苷的正常构象, 同时考察了结合上人血清白蛋白后不同浓度黄芩素和黄芩苷的吸附方式差别.