Department of Medical Chemistry, Key Laboratory of Medical Molecular Probes, School of Basic Medicine, Xinxiang Medical University, Xinxiang, Henan 453003, PR China.
Department of Medical Chemistry, Key Laboratory of Medical Molecular Probes, School of Basic Medicine, Xinxiang Medical University, Xinxiang, Henan 453003, PR China.
Spectrochim Acta A Mol Biomol Spectrosc. 2022 May 5;272:120983. doi: 10.1016/j.saa.2022.120983. Epub 2022 Feb 3.
In this study, the interaction between gold nanoparticles (AuNPs) and proteins (including lysozyme, trypsin, pepsin, γ-globulin and hemoglobin) was investigated by UV-visible absorption spectroscopy, fluorescence spectroscopy, circular dichroism (CD) spectroscopy and protein activity assay. AuNPs was synthesized using reduction of HAuCl with sodium citrate. The formation of AuNPs was confirmed from the characteristic surface plasmon resonance band at 521 nm and transmission electron microscopy revealed the average particle size was about 10 nm. The results reveal that AuNPs can interact with proteins to form a "protein corona (PC)", but the protein concentration required to form a relatively stable PC is not the same. The quenching mechanism of proteins by AuNPs is arisen from static quenching. The binding constants of AuNPs with proteins are in the range from 10 to 10 L mol, and the order is pepsin > γ-globulin > hemoglobin > trypsin > lysozyme at 298 K. Van der Waals forces and hydrogen bonds are the main forces for the lysozyme-AuNPs system. The interaction between trypsin/pepsin/γ-globulin/hemoglobin and AuNPs is mainly by hydrophobic interaction. The addition of AuNPs has an effect on the secondary structure of proteins as confirmed from CD spectra. The change in secondary structure of different proteins is different and seems to have little relation with the binding constant. The activity of lysozyme/trypsin/pepsin decreases with the addition of AuNPs.
在这项研究中，通过紫外-可见吸收光谱、荧光光谱、圆二色性（CD）光谱和蛋白质活性测定研究了金纳米粒子（AuNPs）与蛋白质（包括溶菌酶、胰蛋白酶、胃蛋白酶、γ-球蛋白和血红蛋白）之间的相互作用。AuNPs 是通过柠檬酸钠还原 HAuCl 合成的。在 521nm 处的特征表面等离子体共振带和透射电子显微镜表明平均粒径约为 10nm，证实了 AuNPs 的形成。结果表明，AuNPs 可以与蛋白质相互作用形成“蛋白质冠（PC）”，但形成相对稳定的 PC 所需的蛋白质浓度并不相同。AuNPs 使蛋白质猝灭的机制是静态猝灭。AuNPs 与蛋白质的结合常数在 10 到 10 L/mol 范围内，298K 时的顺序为胃蛋白酶>γ-球蛋白>血红蛋白>胰蛋白酶>溶菌酶。在溶菌酶-AuNPs 体系中，范德华力和氢键是主要作用力。胰蛋白酶/胃蛋白酶/γ-球蛋白/血红蛋白与 AuNPs 的相互作用主要通过疏水相互作用。AuNPs 的加入对蛋白质的二级结构有影响，这可以从 CD 光谱得到证实。不同蛋白质的二级结构变化不同，似乎与结合常数关系不大。溶菌酶/胰蛋白酶/胃蛋白酶的活性随着 AuNPs 的加入而降低。
