论文部分内容阅读
目的研究咖啡因(CAF)与人血清白蛋白(HSA)间非共价结合特征,探讨CAF在血液中的存在方式。方法在模拟人体生理条件下,应用分子光谱技术,确定CAF与HSA相互作用方式、主要作用力类型及热力学参数。结果 CAF通过动态猝灭机制导致HSA荧光猝灭。当作用温度为298K和310K时,CAF与HSA表观结合常数(Kb)分别为3.35×105和9.53×104L·mol-1,结合位点数分别为1.23和1.09;二者结合距离为4.76 nm;主要作用力为氢键或范德华力;同步荧光图谱表明色氨酸、苯丙氨酸残基所处微环境极性增强。结论 CAF与HSA相互作用并形成超分子化合物,该结合作用是一自发过程。
Objective To study the characteristics of non-covalent bonding between caffeine (CAF) and human serum albumin (HSA) and to explore the way of CAF in blood. Methods Under simulated human physiological conditions, molecular interaction spectroscopy was used to determine the mode of interaction between CAF and HSA, the main force types and thermodynamic parameters. Results CAF caused fluorescence quenching of HSA through dynamic quenching mechanism. The apparent binding constants (Kb) of CAF and HSA were 3.35 × 105 and 9.53 × 104L · mol-1 at 298K and 310K, respectively, and the number of binding sites was 1.23 and 1.09, respectively. The binding distance between the two was 4.76 nm. The main force for the hydrogen bond or van der Waals force; synchronous fluorescence spectroscopy showed that tryptophan, phenylalanine residues in micro-environment where the polarity increases. Conclusions CAF interacts with HSA and forms a supramolecular compound, which is a spontaneous process.