Cell-penetrating-peptide-coated nanoribbons for intracellular nanocarriers
Cell-penetrating-peptide-coated nanoribbons for intracellular nanocarriers
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DOI：
10.1002/anie.200604576
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发表时间：
2007-01-01
影响因子：
16.6
通讯作者：
Lee, Myongsoo
中科院分区：
文献类型：
--
作者：
Lim, Yong-beom;Lee, Eunji;Lee, Myongsoo
设计分子的自组装是构建新型超分子结构的有力途径。[1,2]自组装纳米结构在生物领域的应用越来越广泛，包括分子检测、药物传递和基因传递。[3-6]在开发自组装生物材料时，可以考虑的最重要的一点是纳米结构的精确控制，有效的功能化以适应特定的生物应用，以及构建块的生物相容性。在许多类型的分子构建块中，基于肽的构建块具有其组成氨基酸具有生物相容性和结构多样性的优势。α-螺旋、β-片和疏水相互作用是肽组装的主要驱动力，通常导致卷曲的α-螺旋肽束、β-片肽带或管和圆柱形胶束。[7-10]除了天然存在的β-片肽，如β淀粉样蛋白，许多人工β-片肽已被设计大多数人工β片肽序列的设计原则是将带正电、疏水和带负电的氨基酸交替放置。带相反电荷的氨基酸之间的相互吸引和疏水氨基酸之间的疏溶剂相互作用的结合是正确的β-片氢键排列的驱动力，其中双层肽带的形成是最有利的。双层带通过每个β带的疏水表面之间的相互作用来稳定，然后在带内部产生疏水界面。我们设想，条带内部的疏水界面是封装疏水分子的合适位置，因此可以潜在地用于药物输送应用。在这里，我们报道了细胞穿透肽（CPPs）纳米结构的表面功能化，并成功地将疏水分子包封在肽纳米带结构内，同时保留了带的形态（图1）。肽t - β p是为自组装而设计的，由三个功能块组成，一个TatCPP块（GRKKRRQRRRPPQ; Tat48-60），一个柔性连接块（GSGG）和一个β-片组装块（FKFEFKFEFKFE；方案1）。cps由能够穿透细胞膜的短链氨基酸组成许多阳离子CPP，包括来自人类免疫缺陷病毒1型（HIV-1） Tat蛋白的Tat CPP，已被证明可以有效地穿过细胞质膜和核孔复合物（NPC）屏障。柔性连接块被设计为将Tat CPP块与β-sheet组装块解耦，从而最大限度地减少它们之间的不良相互作用。（FKFE） n序列已被证明可以形成β-薄片介导的纳米结构，其中双层带是最稳定的结构。[11a]双分子层通过β带一侧苯丙氨酸残基的疏水和π- π-堆叠相互作用稳定（图1）。纯水中t - β p的CD谱在201 nm处表现出很强的负最小值，在215nm处表现出非常弱的最小值，表明随机线圈结构最普遍，β-薄片形成最少（图2a）。这些结果表明，Tat CPP和β-片组装块在纯水中主要形成随机线圈结构。已知Tat CPP在溶液中形成随机线圈结构我们假设，由于非特异性静电相互作用，t - β p中众所周知的β片组装块几乎不会形成β片。
The self-assembly of designed molecules is a powerful approach for the construction of novel supramolecular architectures.[1, 2] Self-assembled nanostructures are finding growing use in biological applications, which include molecular detection, drug delivery, and gene delivery.[3–6] The most important points that can be considered in developing selfassembled biomaterials are the precise control of nanostructures, effective functionalization to suit for the specific bioapplications, and the biocompatibility of the building blocks. Of the many types of molecular building blocks, peptide-based building blocks have the advantage that their constituent amino acids are biocompatible and structurally diverse. The α-helical, β-sheet, and hydrophobic interactions have been the main driving forces for the peptide assemblies and generally result in coiled-coil α-helical peptide bundles, β-sheet peptide ribbons or tubes, and cylindrical micelles.[7–10] Besides the naturally occurring β-sheet peptides, such as βamyloid, many artificial β-sheet peptides have been designed.[11] The design principle for most of the artificial βsheet peptide sequences is the alternating placement of positively charged, hydrophobic, and negatively charged amino acids. The combination of attraction between oppositely charged amino acids and solvophobic interactions between hydrophobic amino acids is the driving force for the proper β-sheet hydrogen-bonding arrangement in which the formation of a bilayered peptide ribbon is most favorable. The bilayered ribbon is stabilized by the interactions between hydrophobic surfaces of each β tape, which then generates a hydrophobic interface inside the ribbon. We envisioned that the hydrophobic interface inside the ribbon is a suitable place to encapsulate hydrophobic molecules and can therefore be potentially used for drug-delivery applications. Herein, we report the surface functionalization of nanostructures with cell-penetrating peptides (CPPs) and the successful encapsulation of hydrophobic molecules inside the peptide nanoribbon structure while preserving the ribbon morphology (Figure 1).The peptide TβP is designed for self-assembly and is composed of three functional blocks, a TatCPP block (GRKKRRQRRRPPQ; Tat48–60), a flexible-linker block (GSGG), and a β-sheet assembly block (FKFEFKFEFKFE; Scheme 1). The CPPs consist of a short strand of amino acids that are capable of penetrating cell membranes.[12] Many cationic CPPs, including Tat CPP from human immunodeficiency virus type-1 (HIV-1) Tat protein, have been shown to efficiently cross the cytoplasmic membrane and the nucleus pore complex (NPC) barriers. The flexible-linker block was designed to decouple the Tat CPP block from the β-sheet assembly block, thereby minimizing undesirable interactions between them. The (FKFE) n sequence has been shown to form β-sheet-mediated nanostructures in which the bilayered ribbon is the most stable structure.[11a] The bilayer is stabilized by hydrophobic and π–π-stacking interactions of phenylalanine residues on one face of the β tape (Figure 1). The CD spectrum of TβP in pure water showed a strong negative minimum at 201 nm and very weak minimum at 215nm, indicating that random-coil structures are most prevalent and β-sheet formation is minimal (Figure2a). These results indicate that both the Tat CPP and the β-sheet assembly blocks predominantly form random-coil structures in pure water. The Tat CPP is known to form a random-coil structure in solution.[13] We hypothesized that the well-known β-sheet assembly block in TβP forms hardly any β sheets because of nonspecific electrostatic interactions …