Department of Chemistry , Stanford University , Stanford , California 94305 , United States.
Department of Psychiatry and Behavioral Sciences , Stanford University , Stanford , California 94305 , United States.
Nano Lett. 2019 Oct 9;19(10):6955-6963. doi: 10.1021/acs.nanolett.9b02266. Epub 2019 Sep 25.
Magnetogenetics is a new field that leverages genetically encoded proteins and protein assemblies that are sensitive to magnetic fields to study and manipulate cell behavior. Theoretical studies show that many proposed magnetogenetic proteins do not contain enough iron to generate substantial magnetic forces. Here, we have engineered a genetically encoded ferritin-containing protein crystal that grows inside mammalian cells. Each of these crystals contains more than 10 million ferritin subunits and is capable of mineralizing substantial amounts of iron. When isolated from cells and loaded with iron , these crystals generate magnetic forces that are 9 orders of magnitude larger than the forces from the single ferritin cages used in previous studies. These protein crystals are attracted to an applied magnetic field and move toward magnets even when internalized into cells. While additional studies are needed to realize the full potential of magnetogenetics, these results demonstrate the feasibility of engineering protein assemblies for magnetic sensing.
磁遗传学是一个新兴领域，它利用对磁场敏感的基因编码蛋白和蛋白组装体来研究和操纵细胞行为。理论研究表明，许多提出的磁遗传学蛋白中并不含有足够的铁来产生实质性的磁场力。在这里，我们设计了一种基因编码的含铁蛋白晶体，它在哺乳动物细胞内生长。这些晶体中的每一个都含有超过 1000 万个铁蛋白亚基，能够矿化大量的铁。当从细胞中分离出来并加载铁时，这些晶体产生的磁场力比以前研究中使用的单个铁蛋白笼大 9 个数量级。这些蛋白晶体被施加的磁场吸引，并在被内化到细胞内时向磁铁移动。虽然还需要进一步的研究来实现磁遗传学的全部潜力，但这些结果证明了为磁传感工程设计蛋白组装体的可行性。
