Revealing Fast Structural Dynamics in pH-Responsive Peptides with Time-Resolved X-ray Scattering.
Revealing Fast Structural Dynamics in pH-Responsive Peptides with Time-Resolved X-ray Scattering.
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DOI：
10.1021/acs.jpcb.9b00072
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发表时间：
2019-02
期刊：
影响因子：
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通讯作者：
Dolev Rimmerman;Denis Leshchev;Darren J. Hsu;Jiyun Hong;B. Abraham;R. Henning;I. Kosheleva;Lin X. Chen
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文献类型：
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作者：
Dolev Rimmerman;Denis Leshchev;Darren J. Hsu;Jiyun Hong;B. Abraham;R. Henning;I. Kosheleva;Lin X. Chen
许多生物材料可以适应局部生物环境（例如pH值、温度或离子组成）的变化，以调节功能或传递有效负载。这种对环境扰动的适应通常是一个分层过程，从局部结构水平的响应开始，然后传播到超分子和大分子尺度。了解扰动后发生的快速结构动力学对于合理设计功能生物材料是重要的。然而，很少有纳秒时间分辨的方法可以同时探测分子内和分子间尺度的高结构分辨率。在这里，我们利用时间分辨的X射线散射探测纳秒到微秒的结构动力学的聚-L-谷氨酸进行质子化，通过pH值的跳跃引发的光酸的光激发。我们的研究结果提供了深入了解质子化诱导的层次变化的包装的肽链，螺旋结构的形成，以及相关的崩溃的肽链。
Many biomaterials can adapt to changes in the local biological environment (such as pH, temperature, or ionic composition) in order to regulate function or deliver a payload. Such adaptation to environmental perturbation is typically a hierarchical process that begins with a response at a local structural level and then propagates to supramolecular and macromolecular scales. Understanding fast structural dynamics that occur upon perturbation is important for rational design of functional biomaterials. However, few nanosecond time-resolved methods can probe both intra- and intermolecular scales simultaneously with a high structural resolution. Here, we utilize time-resolved X-ray scattering to probe nanosecond to microsecond structural dynamics of poly-l-glutamic acid undergoing protonation via a pH jump initiated by photoexcitation of a photoacid. Our results provide insights into the protonation-induced hierarchical changes in packing of peptide chains, formation of a helical structure, and the associated collapse of the peptide chain.