"Ilie Murgulescu" Institute of Physical Chemistry, Romanian Academy, Splaiul Independentei 202, 060021 Bucharest, Romania.
Int J Mol Sci. 2024 Jan 11;25(2):936. doi: 10.3390/ijms25020936.
The thermal stability of bovine serum albumin (BSA) in Tris buffer, as well as the effect of sinapic acid (SA) on protein conformation were investigated via calorimetric (differential scanning microcalorimetry-μDSC), spectroscopic (dynamic light scattering-DLS; circular dichroism-CD), and molecular docking approaches. μDSC data revealed both the denaturation (endotherm) and aggregation (exotherm) of the protein, demonstrating the dual effect of SA on protein thermal stability. With an increase in ligand concentration, (i) protein denaturation shifts to a higher temperature (indicating native form stabilization), while (ii) the aggregation process shifts to a lower temperature (indicating enhanced reactivity of the denatured form). The stabilization effect of SA on the native structure of the protein was supported by CD results. High temperature (338 K) incubation induced protein unfolding and aggregation, and increasing the concentration of SA altered the size distribution of the protein population, as DLS measurements demonstrated. Complementary information offered by molecular docking allowed for the assessment of the ligand binding within the Sudlow's site I of the protein. The deeper insight into the SA-BSA interaction offered by the present study may serve in the clarification of ligand pharmacokinetics and pharmacodynamics, thus opening paths for future research and therapeutic applications.
通过量热法（差示扫描微量热法-μDSC）、光谱法（动态光散射-DLS；圆二色性-CD）和分子对接方法研究了牛血清白蛋白（BSA）在 Tris 缓冲液中的热稳定性以及芥子酸（SA）对蛋白质构象的影响。μDSC 数据显示了蛋白质的变性（吸热）和聚集（放热），表明 SA 对蛋白质热稳定性具有双重影响。随着配体浓度的增加，（i）蛋白质变性向更高的温度移动（表明天然形式的稳定性），而（ii）聚集过程向更低的温度移动（表明变性形式的反应性增强）。SA 对蛋白质天然结构的稳定作用得到了 CD 结果的支持。高温（338 K）孵育诱导蛋白质展开和聚集，而增加 SA 的浓度改变了蛋白质群体的大小分布，如 DLS 测量所示。分子对接提供的补充信息允许评估配体在蛋白质 Sudlow 位点 I 内的结合。本研究对 SA-BSA 相互作用的更深入了解可能有助于阐明配体的药代动力学和药效动力学，从而为未来的研究和治疗应用开辟道路。
