Caspi Yaron, Zbaida David, Cohen Hagai, Elbaum Michael
Department of Materials and Interfaces, The Weizmann Institute of Science, Rehovot 76100, Israel.
Nano Lett. 2008 Nov;8(11):3728-34. doi: 10.1021/nl801975q. Epub 2008 Oct 25.
The nuclear pore complex is a large protein channel present universally in eukaryotic cells. It generates an essential macromolecular separation between the nucleus and cytoplasm. The transport mechanism relies on recognition of molecular cargos by receptor proteins, and on specific interaction between the receptors and the pores. We present a chemical mimic of this "receptor-mediated" transport using modified nanoporous membrane filters, polyisopropylacrylamide as the carrier molecule, or receptor, and single-stranded DNA as the cargo. We show that a complex of ssDNA and polyisopropylacrylamide diffuses faster through the modified pores than does the bare ssDNA, in spite of the larger size of the complex. The mobile polymer thus acts as a soluble receptor to usher a macromolecular cargo specifically through the pores.
核孔复合体是真核细胞中普遍存在的一种大型蛋白质通道。它在细胞核和细胞质之间形成了至关重要的大分子分隔。运输机制依赖于受体蛋白对分子货物的识别，以及受体与核孔之间的特异性相互作用。我们利用修饰的纳米多孔膜过滤器、聚异丙基丙烯酰胺作为载体分子（即受体）以及单链DNA作为货物，展示了这种“受体介导”运输的化学模拟。我们发现，尽管单链DNA与聚异丙基丙烯酰胺的复合物尺寸更大，但它在修饰孔中的扩散速度比裸露的单链DNA更快。因此，这种可移动的聚合物充当了可溶性受体，引导大分子货物特异性地穿过这些孔。
