作为触发β片自我组装和在阴性和同位素相之间可逆切换的触发剂的pH值
Amalia Aggeli1, Mark Bell, Lisa M Carrick
1Centre for Self-Organising Molecular Systems, University of Leeds, UK.
Journal of the American Chemical Society
|August 9, 2003
概括
研究人员设计了可以通过调整pH,快速自我组装成像凝一样有序的结构的. 这种pH触发控制提供了一种快速和可逆的方法,用于从合成中创建先进的软材料.
科学领域:
- 超分子化学 超分子化学
- 材料科学 材料科学 材料科学
- 生物技术是生物技术.
背景情况:
- 合成的分层自我组装成β片结构 (带,带,纤维,纤维) 是通往软固体类材料的有希望的途径.
- 现有的自组合方法,如冷化溶解,耗时 (数小时至数天).
研究的目的:
- 开发一种快速和可逆的方法,使用pH控制的自我组装.
- 设计合成可以在pH值变化引发的不同状态之间过渡 (例如,同位素流体到尼马基凝).
主要方法:
- 加入酸性 (Glu) 或基性 (Orn) 氨基酸到11氨基酸序列中.
- 研究pH对的自组合动力学和物质状态 (内马基凝,同otropic流体) 的影响.
- 使用酸定位来描述嵌入的氨基酸残留物的脱质化行为.
主要成果:
- 的自我组装成有序的纤维状结构可以通过pH变化快速 (几秒钟) 和可逆地控制.
- 设计的 (P(11) - 4和P(11) - 5) 在同位素流体和阴性凝状态之间表现出pH依赖的过渡.
- 自组装过程是由Glu和Orn残留物质的质子化状态影响的静电相互作用控制的.
结论:
- 结合Glu或Orn残留物,可以精确地通过pH介导控制的自我组装.
- 这种方法为制造基于的软材料的传统方法提供了更快的替代方案.
- 这些发现为开发具有可调节性质的响应性材料提供了设计原则.
相关概念视频
pH
The potential of hydrogen (pH) is a measure of the acidity or basicity of a water-based solution determined by the concentration of hydronium ions (H3O+). In one liter of pure water at neutral pH, there are 1×10−7 moles of hydronium ions. However, the extensive range of hydronium ion concentrations present in water-based solutions makes measuring pH in moles cumbersome. Therefore, a pH scale was developed to convert moles of hydronium ions into the negative logarithm of the hydronium ion...
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Buffer solutions do not have an unlimited capacity to keep the pH relatively constant . Instead, the ability of a buffer solution to resist changes in pH relies on the presence of appreciable amounts of its conjugate weak acid-base pair. When enough strong acid or base is added to substantially lower the concentration of either member of the buffer pair, the buffering action within the solution is compromised.
The buffer capacity is the amount of acid or base that can be added to a given volume...
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Indicators
Certain organic substances change color in dilute solution when the hydronium ion concentration reaches a particular value. For example, phenolphthalein is a colorless substance in any aqueous solution with a hydronium ion concentration greater than 5.0 × 10−9 M (pH < 8.3). In more basic solutions where the hydronium ion concentration is less than 5.0 × 10−9 M (pH > 8.3), it is red or pink. Substances such as phenolphthalein, which can be used to determine the pH of a solution, are called...
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