Tuning the Structure and Chiroptical Properties of Gold Nanoparticle Single Helices via Peptide Sequence Variation
Tuning the Structure and Chiroptical Properties of Gold Nanoparticle Single Helices via Peptide Sequence Variation
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DOI：
10.1021/jacs.9b08798
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发表时间：
2019-10-02
影响因子：
15
通讯作者：
Rosi, Nathaniel L.
中科院分区：
文献类型：
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作者：
Mokashi-Punekar, Soumitra;Walsh, Tiffany R.;Rosi, Nathaniel L.
正如肽的功能是由组成氨基酸的位置、顺序和整体排列决定的一样，纳米粒子（NP）的光学性质也受到组成纳米粒子的大小、尺寸和排列的影响。在这项工作中，我们证明了肽序列可以被编程来指导手性螺旋金NP （AuNP）超结构的结构和手性活性，这是一种在传感、检测和光学应用中具有潜力的手性纳米材料。金结合肽偶联家族C-18-(PEPAuM,x)(2)和C-18-(PEPAuM-ox,x)(2)在肽序列（PEPAu = AYSS-GAPPMPPF/PEPAuM-ox = AYSSGAPPM(ox)PPF）中蛋氨酸(M)/蛋氨酸亚砜（M-ox）的位置（x = 7、9和11）不同，用于控制螺旋NP组合中aunp的宽高比和大小。计算模型显示，氨基酸的变化对肽- aunp相互作用有深远的影响，最终导致对NP大小的控制。C-18-(PEPAuM,x)(2) （x = 7,9和11）生成不规则的双螺旋超结构，包括球形aunp，而C-18-(PEPAuM-ox,x)(2) （x = 9,11）生成单螺旋组合，包括椭圆形或棒状的aunp。此外，当M/M-ox放置在x = 11时，观察到的分量aunp较大，而当M/M-ox放置在x = 7时，观察到的分量aunp较小。纳米尺度结构的变化表现在可观察到的热带信号强度差异上。最终，我们通过简单的肽一级序列的分子水平调整，实现了手性AuNP超结构的结构和性质的巨大变化。
Just as peptide function is determined by the position, sequence, and overall arrangement of constituent amino acids, the optical properties of nanoparticle (NP) assemblies are influenced by the size, dimensions, and arrangement of constituent NPs. In this work, we demonstrate that peptide sequence can be programmed to direct the structure and chiroptical activity of chiral helical gold NP (AuNP)superstructures, a growing class of chiral nanomaterials with potential in sensing, detection, and optics-based applications. Gold-binding peptide conjugate families, C-18-(PEPAuM,x)(2) and C-18-(PEPAuM-ox,x)(2), that differ in the position (x = 7, 9, and 11) of methionine (M)/methionine sulfoxide (M-ox) within the peptide sequences (PEPAu = AYSS-GAPPMPPF/PEPAuM-ox = AYSSGAPPM(ox)PPF) are employed to control the aspect ratio and size of AuNPs within helical NP assemblies. Computational modeling reveals that the amino acid variations have a profound effect on peptide-AuNP interactions that ultimately lead to control over NP size. C-18-(PEPAuM,x)(2) (x = 7, 9, and 11) yield irregular double-helical superstructures comprising spherical AuNPs, while C-18-(PEPAuM-ox,x)(2) (x = 9, 11) yield single-helical assemblies comprising oblong or rod-shaped AuNPs. Further, component AuNPs are larger when M/M-ox is placed at x = 11, while smaller component AuNPs are observed when M/M-ox is placed at x = 7. Changes in nanoscale structures manifest themselves in observable differences in chiroptical signal intensity. Ultimately, we achieve dramatic variance in the structure and properties of chiral AuNP superstructures via simple molecular-level tuning of peptide primary sequence.