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利用多种荧光光谱法、紫外光谱法并结合分子模拟等方法,表征了模拟生理条件下一种植物药活性组分考拉维酸(KA)影响人血清白蛋白(HSA)的结构信息.同步荧光及紫外光谱证实考拉维酸的存在影响了HSA的微环境;二维及三维荧光光谱表明考拉维酸可以猝灭HSA的内源荧光,使其构象发生变化.荧光偏振的测定提供了考拉维酸与HSA作用后生成的配合物弛豫时间与聚集特性的信息,揭示KA的存在使HSA的流动性和微粘度发生变化.定量求得不同温度下(298、308和318 K)考拉维酸与HSA作用的键合参数和热力学参数.分子模拟表明考拉维酸键合位点于HSA分子的疏水腔内,并与赖氨酸Lys195和天冬氨酸Asp451形成三个氢键,与HSA的键合模式主要是疏水作用;位点竞争实验证明考拉维酸在HSA亚结构域的位点II位发生作用.另外,获得的相关物理化学参数从分子水平上揭示了考拉维酸与HSA相互作用的机制.结果表明,HSA对考拉维酸有较强的结合能力,提示人血清白蛋白对考拉维酸可起到储存和转运的作用.
The structure information of human serum albumin (HSA), which is the active component of a plant medicine under simulated physiological conditions, was characterized by various fluorescence spectroscopy, ultraviolet spectroscopy and molecular simulation. Fluorescence and UV spectroscopy confirmed that the presence of kojic acid affects the microenvironment of HSA; two-dimensional and three-dimensional fluorescence spectra indicate that kojic acid quenches the endogenous fluorescence of HSA and changes its conformation.The determination of fluorescence polarization provides The results showed that the presence of KA changed the fluidity and microviscosity of HSA.Changes in the temperature (298, 308 and 318 K) Bonding parameters and thermodynamic parameters of kojic acid and HSA interactions Molecular modeling shows that the kojic acid binding site is within the hydrophobic cavity of the HSA molecule and forms three hydrogens with lysine Lys195 and aspartic acid Asp451 , The binding mode with HSA is mainly hydrophobic and the site competition experiment shows that kojic acid acts in the position II of HSA subdomain.In addition, the related physicochemical parameters obtained reveal molecular level Llamaic acid interacts with HSA Mechanisms. The results showed that, HSA clavulanic acid test for strong binding ability, suggesting that human serum albumin to test clavulanic acid may play a role in storage and transport.