Coassembly in Binary Mixtures of Peptide Amphiphiles Containing Oppositely Charged Residues
Coassembly in Binary Mixtures of Peptide Amphiphiles Containing Oppositely Charged Residues
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DOI：
10.1021/la400163q
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发表时间：
2013-04-23
期刊：
影响因子：
3.9
通讯作者：
Castelletto, V.
中科院分区：
文献类型：
--
作者：
Hamley, I. W.;Dehsorkhi, A.;Castelletto, V.
本文研究了含两个阴离子残基的两亲肽（PA）C-16-ETTES及其与含两个阳离子残基的C-16-KTTKS的混合物在水中的自组装。肽两亲物均包含十六烷基烷基链和含有两个带电残基的带电五肽头基。对于C-16-ETTES，通过荧光实验确定临界聚集浓度。FTIR和CD光谱用于检查β-折叠形成。TEM显示高度延伸的带状纳米结构，其中一些条纹区域对应于从侧面观察的双层结构。小角X射线散射显示主要的5.3 nm双层间距沿着为3 nm间距。这些间距分别分配给主要的水合双层和一部分脱水双层。在混合物中观察到协同自组装的迹象，包括肽两亲物聚集体（延伸的带结构）的捆绑减少和β-折叠形成增强。
The self-assembly in water of designed peptide amphiphile (PA) C-16-ETTES containing two anionic residues and its mixtures with C-16-KTTKS containing two cationic residues has been investigated Multiple spectroscopy, microscopy, and scattering techniques are used to examine ordering extending from the beta-sheet structures up to the fibrillar aggregate structure. The peptide amphiphiles both comprise a hexadecyl alkyl chain and a charged pentapeptide headgroup containing two charged residues. For C-16-ETTES, the critical aggregation concentration was determined by fluorescence experiments. FTIR and CD spectroscopy were used to examine beta-sheet formation. TEM revealed highly extended tape nanostructures with some striped regions corresponding to bilayer structures viewed edge-on. Small-angle X-ray scattering showed a main 5.3 nm bilayer spacing along with a 3 nm spacing. These spacings are assigned respectively to predominant hydrated bilayers and a fraction of dehydrated bilayers. Signs of cooperative self-assembly are observed in the mixtures, including reduced bundling of peptide amphiphile aggregates (extended tape structures) and enhanced beta-sheet formation.