Jones Brad H, Martinez Alina M, Wheeler Jill S, Spoerke Erik D
Sandia National Laboratories, Electronic, Optical, and Nano Materials, PO Box 5800, MS 1411, Albuquerque, NM 87185, USA.
Soft Matter. 2015 May 14;11(18):3572-80. doi: 10.1039/c5sm00522a.
The secondary structure of peptides in the presence of interacting additives is an important topic of study, having implications in the application of peptide science to a broad range of modern technologies. Surfactants constitute a class of biologically relevant compounds that are known to influence both peptide conformation and aggregation or assembly. We have characterized the secondary structure of a linear nonapeptide composed of a hydrophobic alanine/phenylalanine core flanked by hydrophilic acid/amine units. We show that the anionic surfactant sodium dodecyl sulfate (SDS) induces the formation of β-sheets and macroscopic gelation in this otherwise unstructured peptide. Through comparison to related additives, we propose that SDS-induced secondary structure formation is the result of amphiphilicity created by electrostatic binding of SDS to the peptide. In addition, we demonstrate a novel utility of surfactants in manipulating and stabilizing peptide nanostructures. SDS is used to simultaneously induce secondary structure in a peptide and to inhibit the activity of a model enzyme, resulting in a peptide hydrogel that is impervious to enzymatic degradation. These results complement our understanding of the behavior of peptides in the presence of interacting secondary molecules and provide new potential pathways for programmable organization of peptides by the addition of such components.
在存在相互作用添加剂的情况下，肽的二级结构是一个重要的研究课题，对肽科学在广泛现代技术中的应用具有重要意义。表面活性剂是一类与生物相关的化合物，已知它们会影响肽的构象以及聚集或组装。我们已经对一种线性九肽的二级结构进行了表征，该九肽由一个疏水的丙氨酸/苯丙氨酸核心以及两侧的亲水酸/胺单元组成。我们表明，阴离子表面活性剂十二烷基硫酸钠（SDS）在这种原本无结构的肽中诱导形成β-折叠和宏观凝胶化。通过与相关添加剂进行比较，我们提出SDS诱导的二级结构形成是SDS与肽静电结合产生的两亲性的结果。此外，我们展示了表面活性剂在操纵和稳定肽纳米结构方面的新用途。SDS被用于同时诱导肽中的二级结构并抑制一种模型酶的活性，从而形成一种对酶降解具有抗性的肽水凝胶。这些结果补充了我们对肽在存在相互作用的二级分子时行为的理解，并为通过添加此类成分对肽进行可编程组织提供了新的潜在途径。
