厄他培南与人血清清蛋白体外相互作用的理化特性

研究新型碳青霉烯类抗菌素厄他培南（ertapenem, ERT）与人血清清蛋白（human serum albumin，HSA）的体外相互作用的物理化学特性。模拟生理条件下，计算机模拟技术结合荧光光谱和紫外光谱，研究ERT与HSA相互作用机制，荧光光谱实验中，Kq 值远大于2.0×1010 L·(mol·s)-1，ERT对HSA荧光猝灭的Stern-Volmer 曲线有良好的线性关系，表明ERT与HSA的相互作用表现为静态结合过程。HSA的最大发射波长发生轻微红移，说明HSA的微环境发生了改变。ERT与HSA的分子结合距离r值较小，说明发生能量转移现象。同步荧光技术解析出ERT对HSA的结构域微区构象产生影响，使色氨酸残基周围的微区构象及结合位域的疏水性发生改变。荧光相图技术解析出ERT与HSA相互反应呈线性，说明HSA构象型态的变迁为“二态”模型。HSA与ERT相互作用的热力学参数及分子模拟技术建立ERT-HSA结合模型，表明ERT与HSA的相互作用力主要是疏水作用力，兼有氢键作用力的存在。荧光偏振定量证明，HSA与ERT相互作用过程中生成了非共价复合物。光谱实验与计算机模拟结果基本一致，其结果可为研究ERT与HSA相互作用本质提供一定参考。

Physicochemical Characteristics of the Interaction between Ertapenem and HSA in vitro

Physical and chemical characteristics of the in vitro interaction of ertapenem (ERT) with human serum albumin (HSA) are investigated．Following physiological stimulations, the ERT binding with HSA were simulated by computer software and referred to fluorescence spectrometry and ultraviolet spectrum. Kq value was greater than 2.0×1010 L·(mol·s)-1 and ERT to HSA fluorescence quenching of Stern-Volmer curve had a good linear relationship in fluorescence spectrum experiment, which indicated that the interaction of ERT with HSA performance was a static quenching process. The maximum emission wavelength of HSA illustrated a slight red shift phenomenon which suggested the alteration of microenvironment in HSA. The distance between the ERT and HSA was small enough for energy transfer. Synchronous fluorescence technology resolved that the ERT exerted an influence on HSA conformation structure domain micro area conformation, which made the micro zone around the tryptophan residues conformation and hydrophobic binding domain be changed. Fluorescent phase diagram technology resolves that the ERT and HSA interaction was linear relationship which suggested that HSA conformation types of change was “two states” model. Thermodynamic parameters of interaction between HSA and ERT and molecular modeling technique were used to establish ERT-HSA binding model, which suggested that the main force between ERT and HSA was hydrophobic force and the existence of hydrogen bonding forces. The quantitative of fluorescence polarization proved that the process interaction between HSA and ERT generated the non covalent compounds.These data demonstrates an example of joining spectrum experiment with computer simulation in protein structural analysis.