Self-Assembly and Rearrangement of a Polyproline II Helix Peptide on Gold
Self-Assembly and Rearrangement of a Polyproline II Helix Peptide on Gold
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DOI：
10.1021/acs.langmuir.0c03583
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发表时间：
2021-05-11
期刊：
影响因子：
3.9
通讯作者：
Renner, Julie N.
中科院分区：
文献类型：
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作者：
Hostert, Jacob D.;Loney, Charles N.;Renner, Julie N.
聚脯氨酸肽序列由于其有吸引力的性质而作为基于肽的自组装单分子膜（SAM）的锚而受到欢迎。在这项工作中，含有聚脯氨酸II螺旋（PPII）构象的肽的设计和组装在金（Au）。一个石英晶体微天平与耗散被用来表征SAM形成动力学和相关性能。用序列（GPPPPG）（2）C设计肽。结果发现，一个双指数吸附和重排模型描述的结合动力学的PPII含肽Au。在该模型中，初始可逆结合步骤之后是不可逆重排步骤，由参数kt给出。本研究发现，含PPII肽的k（t）约为0.00064 s（-1）。类似地，我们发现含PPII的肽在Au上的吸附（由Δ G（ads）给出）在化学上是有利的（~ 7.8 kcal mol（-1）），并且与Au上的其他常见硫醇封端的SAM相当。此外，我们通过QCM-D，傅里叶变换红外（FTIR）光谱和电化学技术，揭示高分子密度的自组装膜的PPII螺旋组成的SAM的特性。此外，发现这些自组装膜具有高的介电性能。总的来说，这项研究的基本组装机制，特别是，重排PPII含肽的第一次，这将是有用的，在未来的肽为基础的自组装膜的设计具有高表面覆盖率和可重复性。
Polyproline peptide sequences have gained popularity as anchors for peptide-based self-assembled monolayers (SAMs) due to their attractive properties. In this work, peptides containing the polyproline II helix (PPII) conformation were designed and assembled on gold (Au). A quartz crystal microbalance with dissipation was used to characterize SAM formation kinetics and related properties. Peptides were designed with the sequence (GPPPPPG)(2)C. It was discovered that a biexponential adsorption and rearrangement model describes the binding kinetics of the PPII-containing peptide on Au. In this model, an initial reversible binding step is followed by an irreversible rearrangement step, given by parameter kt. This study found k(t) to be approximately 0.00064 s(-1) for the PPII-containing peptides. Similarly, we found that the adsorption of the PPII-containing peptide on Au, given by Delta G(ads), was thermodynamically favorable (-7.8 kcal mol(-1)) and comparable to other common thiol terminated SAMs on Au. Furthermore, we characterized SAM properties via QCM-D, Fourier-transform infrared (FTIR) spectroscopy, and electrochemical techniques to reveal high molecular density SAMs consisting of PPII helices. In addition, these SAMs were found to have high antifouling properties. Overall, this study characterizes the fundamental assembly mechanisms, particularly, rearrangement of PPII-containing peptides for the first time, which will be useful in the designing of future peptide-based SAMs with high surface coverage and antifouling properties.