Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, Universitätsstrasse 5-7, 45117, Essen, Germany.
Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany.
Chembiochem. 2021 Apr 16;22(8):1456-1463. doi: 10.1002/cbic.202000761. Epub 2021 Jan 28.
The surface of ultrasmall gold nanoparticles with an average diameter of 1.55 nm was conjugated with a 14-3-3 protein-binding peptide derived from CRaf. Each particle carries 18 CRaf peptides, leading to an overall stoichiometry of Au(115)Craf(18). The binding to the protein 14-3-3 was probed by isothermal titration calorimetry (ITC) and fluorescence polarization spectroscopy (FP). The dissociation constant (K ) was measured as 5.0 μM by ITC and 0.9 μM by FP, which was close to the affinity of dissolved CRaf to 14-3-3σ. In contrast to dissolved CRaf, which alone did not enter HeLa cells, CRAF-conjugated gold nanoparticles were well taken up by HeLa cells, opening the opportunity to target the protein inside a cell.
平均直径为 1.55nm 的超小金纳米粒子表面连接了一个来源于 CRaf 的 14-3-3 蛋白结合肽。每个粒子携带 18 个 CRaf 肽，导致 Au(115)Craf(18)的总体化学计量比。通过等温滴定量热法（ITC）和荧光偏振光谱法（FP）探测与蛋白质 14-3-3 的结合。通过 ITC 测量得到的解离常数（Kd）为 5.0μM，通过 FP 测量为 0.9μM，这与溶解的 CRaf 与 14-3-3σ 的亲和力相近。与单独不进入 HeLa 细胞的溶解的 CRaf 不同，连接 CRaf 的金纳米粒子被 HeLa 细胞很好地摄取，为在细胞内靶向该蛋白提供了机会。
