School of Life Science and Technology, Tokyo Institute of Technology , Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan.
Graduate School of Engineering, Kyoto University , Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
ACS Nano. 2017 Mar 28;11(3):2410-2419. doi: 10.1021/acsnano.6b06099. Epub 2017 Feb 9.
Crystalline porous materials have been investigated for development of important applications in molecular storage, separations, and catalysis. The potential of protein crystals is increasing as they become better understood. Protein crystals have been regarded as porous materials because they present highly ordered 3D arrangements of protein molecules with high porosity and wide range of pore sizes. However, it remains difficult to functionalize protein crystals in living cells. Here, we report that polyhedra, a natural crystalline protein assembly of polyhedrin monomer (PhM) produced in insect cells infected by cypovirus, can be engineered to extend porous networks by deleting selected amino acid residues located on the intermolecular contact region of PhM. The adsorption rates and quantities of fluorescent dyes stored within the mutant crystals are increased relative to those of the wild-type polyhedra crystal (WTPhC) under both in vitro and in vivo conditions. These results provide a strategy for designing self-assembled protein materials with applications in molecular recognition and storage of exogenous substances in living cell as well as an entry point for development of bioorthogonal chemistry and in vivo crystal structure analysis.
结晶多孔材料因其在分子存储、分离和催化方面的重要应用而受到广泛研究。随着人们对蛋白质晶体的深入了解，其潜在应用也在不断增加。由于蛋白质晶体具有高度有序的三维蛋白质分子排列结构，具有高孔隙率和广泛的孔径范围，因此被认为是多孔材料。然而，在活细胞中对蛋白质晶体进行功能化仍然具有挑战性。在这里，我们报告称，多面体是由昆虫细胞感染杆状病毒产生的多角体蛋白单体（PhM）组成的天然结晶蛋白组装体，通过删除位于 PhM 分子间接触区域的选定氨基酸残基，可以对其进行工程改造，从而扩展多孔网络。与野生型多面体晶体（WTPhC）相比，突变体晶体在体外和体内条件下对荧光染料的吸附速率和储存量均有所增加。这些结果为设计自组装蛋白质材料提供了一种策略，可应用于分子识别和活细胞中外源物质的存储，也为生物正交化学和体内晶体结构分析的发展提供了切入点。
