School of Life Science and Technology, Tokyo Institute of Technology, 4259-B55, Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan.
Nat Commun. 2017 Mar 16;8:14820. doi: 10.1038/ncomms14820.
Protein scaffolds provide unique metal coordination environments that promote biomineralization processes. It is expected that protein scaffolds can be developed to prepare inorganic nanomaterials with important biomedical and material applications. Despite many promising applications, it remains challenging to elucidate the detailed mechanisms of formation of metal nanoparticles in protein environments. In the present work, we describe a crystalline protein cage constructed by crosslinking treatment of a single crystal of apo-ferritin for structural characterization of the formation of sub-nanocluster with reduction reaction. The crystal structure analysis shows the gradual movement of the Au ions towards the centre of the three-fold symmetric channels of the protein cage to form a sub-nanocluster with accompanying significant conformational changes of the amino-acid residues bound to Au ions during the process. These results contribute to our understanding of metal core formation as well as interactions of the metal core with the protein environment.
蛋白质支架提供了独特的金属配位环境，促进了生物矿化过程。预计可以开发蛋白质支架来制备具有重要生物医学和材料应用的无机纳米材料。尽管有许多有前途的应用，但阐明蛋白质环境中金属纳米颗粒形成的详细机制仍然具有挑战性。在本工作中，我们描述了一种通过交联处理脱铁蛋白单晶制备的结晶蛋白质笼，用于对具有还原反应的亚纳米团簇形成的结构特征进行表征。晶体结构分析表明，Au 离子逐渐向蛋白质笼的三面对称通道中心移动，形成亚纳米团簇，同时与 Au 离子结合的氨基酸残基发生显著的构象变化。这些结果有助于我们理解金属核的形成以及金属核与蛋白质环境的相互作用。
