Ludzik Katarzyna, Marcinkowska Monika, Klajnert-Maculewicz Barbara, Huang Liangliang, Jazdzewska Monika, Korolkov Ilya V, Kozlovskiy Artem L, Zdorovets Maxim V, Jasiak Natalia
Department of Physical Chemistry, University of Lodz, Lodz 90-236, Poland.
Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz 90-237, Poland.
J Phys Chem B. 2025 Jul 10;129(27):6757-6764. doi: 10.1021/acs.jpcb.5c00731. Epub 2025 Jun 28.
In a biological medium, nanoparticles (NPs) can spontaneously interact with proteins, adsorb onto their surface, and cause conformational and orientation changes of the proteins. As a result, the protein function is influenced in a complex manner. Therefore, a detailed understanding of the nature and specificity of protein-nanoparticle interactions is crucial for the application of functional NPs in medicine. In the presented work, we studied the interactions of GMA-treated SiO NPs with the FeO core and attached carborane compounds (FeO/TEOS/TMSPM/GMA/Carborane), designed for boron neutron capture therapy, with human serum albumin (HSA) and insulin. We combined different techniques: spectrofluorometry, circular dichroism spectroscopy, and isothermal titration calorimetry to address this issue. The results show that the adsorption of protein onto the NP surface is enthalpy-entropy-driven, with ensuing structural changes of the protein. As for albumin, the percentage of the α-helix structure in the protein is significantly reduced from 87.59 (free protein) to 40.9% for an NP concentration of 1.8 mg/mL, while the content of the β-sheet and random coil increases from 0.48 to 8.78% and from 11.93 to 50.32%, respectively. The interaction between NPs and small protein-insulin is weaker than that for HSA, confirming less negative Δ and a 15% decrease in the α-structure content for the highest concentration of NPs. For both proteins, the exposure on FeO/TEOS/TMSPM/GMA/Carborane affects the polarity of the microenvironment around Trp, which is consequently exposed to a more hydrophobic environment. Calculated values of the radius of gyration and the minimum distance between the proteins and the NPs indicate a stronger interaction and closer binding proximity to the NPs, corroborating experimental observations of the higher binding affinity of HSA to NPs.
在生物介质中，纳米颗粒（NPs）可自发地与蛋白质相互作用，吸附在其表面，并引起蛋白质的构象和取向变化。结果，蛋白质功能受到复杂的影响。因此，详细了解蛋白质 - 纳米颗粒相互作用的性质和特异性对于功能性纳米颗粒在医学中的应用至关重要。在本研究中，我们研究了经甲基丙烯酸缩水甘油酯（GMA）处理的含FeO核且附着有用于硼中子俘获治疗的碳硼烷化合物的SiO纳米颗粒（FeO/TEOS/TMSPM/GMA/碳硼烷）与人血清白蛋白（HSA）和胰岛素的相互作用。我们结合了不同的技术：荧光光谱法、圆二色光谱法和等温滴定量热法来解决这个问题。结果表明，蛋白质在纳米颗粒表面的吸附是由焓 - 熵驱动的，随之蛋白质会发生结构变化。对于白蛋白，当纳米颗粒浓度为1.8 mg/mL时，蛋白质中α - 螺旋结构的百分比从87.59%（游离蛋白质）显著降低至40.9%，而β - 折叠和无规卷曲的含量分别从0.48%增加至8.78%以及从11.93%增加至50.32%。纳米颗粒与小分子蛋白质胰岛素之间的相互作用比与HSA的相互作用弱，这证实了在纳米颗粒最高浓度下，负的Δ值较小且α - 结构含量降低了15%。对于这两种蛋白质，FeO/TEOS/TMSPM/GMA/碳硼烷对色氨酸周围微环境极性的影响，使得色氨酸因此暴露于更疏水的环境中。计算得到的回转半径值以及蛋白质与纳米颗粒之间的最小距离表明，蛋白质与纳米颗粒之间的相互作用更强且结合距离更近，这证实了HSA与纳米颗粒具有更高结合亲和力的实验观察结果。
