Leveraging Peptide Sequence Modification to Promote Assembly of Chiral Helical Gold Nanoparticle Superstructures

Peptide conjugate molecules comprising a goldbinding peptide (e.g., AYSSGAPPMPPF) attached to an aliphatic tail have proven to be powerful agents for directing the synthesis and assembly of gold nanoparticle superstructures, in particular chiral helices having interesting plasmonic chiroptical properties. The composition and structure of these molecular agents can be tailored to carefully tune the structure and properties of gold nanoparticle single and double helices. To date, modifications to the beta-sheet region (AYSSGA) of the peptide sequence have not been exploited to control the metrics and assembly of such superstructures. We report here that systematic peptide sequence variation in a series of gold-binding peptide conjugate molecules can be leveraged not only to affect the assembly of peptide conjugates but also to control the synthesis, assembly, and optical properties of gold nanoparticle superstructures. Depending upon the hydrophobicity of a single-amino acid variant, the conjugates yield either dispersed gold nanoparticles or helical superstructures. These results provide evidence that subtle changes to peptide sequence, via single-amino acid variation in the beta-sheet region, can be leveraged to program structural control in chiral gold nanoparticle superstructures.

包含连接到脂肪族尾部的金结合肽（例如，AYSSGAPPMPPF）的肽共轭分子已被证明是用于指导金纳米粒子超结构合成和组装的有力试剂，特别是具有有趣的等离子体手性光学性质的手性螺旋。这些分子试剂的组成和结构可以进行调整，以精细地调节金纳米粒子单螺旋和双螺旋的结构和性质。到目前为止，尚未利用对肽序列的β -折叠区域（AYSSGA）的修饰来控制此类超结构的度量和组装。我们在此报道，一系列金结合肽共轭分子中的系统性肽序列变化不仅可用于影响肽共轭物的组装，还可用于控制金纳米粒子超结构的合成、组装和光学性质。根据单个氨基酸变体的疏水性，共轭物产生分散的金纳米粒子或螺旋超结构。这些结果提供了证据，表明通过β -折叠区域中的单个氨基酸变化对肽序列进行细微改变，可用于对手性金纳米粒子超结构进行结构控制编程。