Self-Assembly of Short Peptide Amphiphiles: The Cooperative Effect of Hydrophobic Interaction and Hydrogen Bonding
Self-Assembly of Short Peptide Amphiphiles: The Cooperative Effect of Hydrophobic Interaction and Hydrogen Bonding
复制标题
短肽两亲物的自组装：疏水相互作用和氢键的协同作用
DOI：
10.1002/chem.201101970
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发表时间：
2011-11-01
影响因子：
4.3
通讯作者：
Lu, Jian R.
中科院分区：
文献类型：
--
作者：
Han, Shuyi;Cao, Sasa;Lu, Jian R.
氢键、疏水相互作用和氨基酸侧链分子几何结构之间的相互作用对短肽两亲体纳米结构的形成至关重要。开发其实际应用的一个重要步骤是了解不同氨基酸侧链如何调节疏水相互作用和氢键，以及这个过程如何导致纳米结构的大小和形状的控制。在这项研究中，我们设计并合成了三组短的两亲性肽(I(3)K， LI(2)K和L(3)K；L(3)K、L(4)K、L(5)K；I(3)K， I(4)K和I(5)K)，并研究了I和L如何影响它们在水溶液中的自组装。结果表明，I基团具有促进-薄片氢键生长和随后形成纳米纤维形状的强烈倾向。所有I(m)K （m=3-5）多肽都以一致的β -片构象组装成纳米纤维，而由于多肽链包装的几何约束，纳米纤维直径随着m的增加而减小。相比之下，L基团促进β -片结构的倾向较弱，其疏水性占主导地位，导致L(3)K组装中的球状胶束。然而，由于协同疏水效应和随后形成的长纳米纤维，疏水序列数量增加到L(5)K诱导b-sheet构象。因此，L(4)K的组装介于L(3)K和L(5)K之间，类似于LI(2)K在L(3)K、LI(2)K和I(3)K集合中的情况，从疏水相互作用的优势稳定过渡到氢键的优势。因此，疏水长度的变化和L和I的交换可以改变这些简单肽两亲体自组装纳米结构的大小和形状。
The interplay between hydrogen bonding, hydrophobic interaction and the molecular geometry of amino acid side-chains is crucial to the development of nanostructures of short peptide amphiphiles. An important step towards developing their practical use is to understand how different amino acid side-chains tune hydrophobic interaction and hydrogen bonding and how this process leads to the control of the size and shape of the nanostructures. In this study, we have designed and synthesized three sets of short amphiphilic peptides (I(3)K, LI(2)K and L(3)K; L(3)K, L(4)K and L(5)K; I(3)K, I(4)K and I(5)K) and investigated how I and L affected their self-assembly in aqueous solution. The results have demonstrated a strong tendency of I groups to promote the growth of beta-sheet hydrogen bonding and the subsequent formation of nanofibrillar shapes. All I(m)K (m=3-5) peptides assembled into nanofibers with consistent beta-sheet conformation, whereas the nanofiber diameters decreased as m increased due to geometrical constraint in peptide chain packing. In contrast, L groups had a weak tendency to promote beta-sheet structuring and their hydrophobicity became dominant and resulted in globular micelles in L(3)K assembly. However, increase in the number of hydrophobic sequences to L(5)K induced b-sheet conformation due to the cooperative hydrophobic effect and the consequent formation of long nanofibers. The assembly of L(4)K was, therefore, intermediate between L(3)K and L(5)K, similar to the case of LI(2)K within the set of L(3)K, LI(2)K and I(3)K, with a steady transition from the dominance of hydrophobic interaction to hydrogen bonding. Thus, changes in hydrophobic length and swapping of L and I can alter the size and shape of the self-assembled nanostructures from these simple peptide amphiphiles.