Department of Chemistry, National Institute of Technology, Hamirpur, Himachal Pradesh 177005, India.
Protein Pept Lett. 2020;27(8):793-800. doi: 10.2174/0929866527666200129123018.
Silver Nanoparticles (AgNPs) were found to modulate the fibrillation of Bovine Β-Lactoglobulin (BLG).
To gain an insight regarding the mechanism of BLG aggregation modulation by AgNPs at molecular level, studies on the interactions between BLG and AgNPs were carried out.
Protein-ligand interactions were studied based on Trp fluorescence quenching (at four different temperatures), synchronous and three-dimensional fluorescence and circular dichroism spectroscopy (far-UV and near-UV).
Protein-nanoparticles association constant was in the range of 106 -1010 M-1 and the quenching constant was determined as ~107 M-1. Ground state complexation between the protein and nanoparticles was predicted. Change in polarity surrounding the Trp residue was not detected by synchronous and three-dimensional fluorescence spectroscopy. AgNPs caused a global change in the secondary and tertiary structure of the protein as revealed from far-UV and near-UV CD spectroscopy. Enthalpy driven complexation between the protein and nanoparticles indicates the involvement of hydrogen bonding and/or van der Waals interactions.
Modulation of BLG aggregation by AgNPs is due to strong binding of the nanoparticles with BLG, which also causes structural perturbations of the protein.
银纳米粒子（AgNPs）被发现可以调节牛β-乳球蛋白（BLG）的纤维形成。
为了深入了解 AgNPs 在分子水平上调节 BLG 聚集的机制，对 BLG 与 AgNPs 之间的相互作用进行了研究。
基于色氨酸荧光猝灭（在四个不同温度下）、同步和三维荧光以及圆二色性光谱（远紫外和近紫外）研究蛋白质-配体相互作用。
蛋白质-纳米粒子缔合常数在 106-1010 M-1范围内，猝灭常数确定为~107 M-1。预测了蛋白质和纳米粒子之间的基态络合。同步和三维荧光光谱未检测到色氨酸残基周围极性的变化。AgNPs 导致蛋白质的二级和三级结构发生全局变化，远紫外和近紫外 CD 光谱揭示了这一点。蛋白质与纳米粒子之间的焓驱动络合表明氢键和/或范德华相互作用的参与。
AgNPs 对 BLG 聚集的调节是由于纳米粒子与 BLG 的强结合，这也导致了蛋白质的结构扰动。
