Unique self-assembly properties of a bridge-shaped protein dimer with quantum dots
Publication in refereed journal


摘要How protein-protein interaction affects protein-nanoparticle self-assembly is the key to the understanding of biomolecular coating of nanoparticle in biological fluids. However, the relationship between protein shape and its interaction with nanoparticles is still under-exploited because of lack of a well-conceived binding system and a method to detect the subtle change in the protein-nanoparticle assemblies. Noticing this unresolved need, we cloned and expressed a His-tagged SpeA protein that adopts a bridge-shaped dimer structure, and utilized a high-resolution capillary electrophoresis method to monitor assembly formation between the protein and quantum dots (QDs, 5 nm in diameter). We observed that the bridge-shaped structure rendered a low SpeA:QD stoichiometry at saturation. Also, close monitoring of imidazole (Im) displacement of surface-bound protein revealed a unique two-step process. High-concentration Im could displace surface-bound SpeA protein and form a transient QD-protein intermediate, through a kinetically controlled displacement process. An affinity-driven equilibrium step then followed, resulting in re-assembling of the QD-protein complex in about 1 h. Through a temporarily formed intermediate, Im causes a rearrangement of His-tagged proteins on the surface. Thus, our work showcases that the synergistic interplay between QD-His-tag interaction and protein-protein interaction can result in unique properties of protein-nanoparticle assembly for the first time.
著者Wang JH, Jiang PJ, Gao LQ, Yu YS, Lu Y, Qiu L, Wang CL, Xia J
期刊名稱Journal of Nanoparticle Research
關鍵詞Capillary electrophoresis; Co-assembly; Dimeric protein; Quantum dots; SpeA
Web of Science 學科類別Chemistry; Chemistry, Multidisciplinary; CHEMISTRY, MULTIDISCIPLINARY; Materials Science; Materials Science, Multidisciplinary; MATERIALS SCIENCE, MULTIDISCIPLINARY; Nanoscience & Nanotechnology; NANOSCIENCE & NANOTECHNOLOGY; Science & Technology - Other Topics

上次更新時間 2020-17-09 於 00:30