Quartz crystal microbalance studies of multilayer glucagon fibrillation at the solid-liquid interface
Quartz crystal microbalance studies of multilayer glucagon fibrillation at the solid-liquid interface
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DOI：
10.1529/biophysj.107.109686
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发表时间：
2007-09-01
影响因子：
3.4
通讯作者：
Besenbacher, Flemming
中科院分区：
文献类型：
--
作者：
Hovgaard, Mads Bruun;Dong, Mingdong;Besenbacher, Flemming
我们首次使用带耗散的石英晶体微天平（QCM-D）监测了多层淀粉样蛋白原位沉积过程中层厚和粘弹性的变化。通过原子力显微镜成像，在界面成核和胰高血糖素的生长之间建立了明确的相关性。brils和QCM- D响应。两种技术的结合使我们能够研究界面纤颤过程的时间演变。我们利用Kelvin- Voigt粘弹性模型的扩展对QCM-D数据进行了建模。观察到三个相。纤颤过程：1)形成刚性多层胰高血糖素单体并缓慢重排；2)，这个多层随后演变成一个更粘弹性的层，包含一个从多个成核位置生长的微米长的原纤维的多态网络；3)纤维的形成由于体相单体的耗尽而有效地停止，尽管该过程可以通过随后添加新的单体而在没有滞后期的情况下继续进行。QCM- D技术的稳健性，通过互补原子力显微镜研究得到巩固，应该可以将被认为参与斑块形成过程的不同成分结合起来，从而在体外建立淀粉样斑块形成的真实模型。
We have used a quartz crystal microbalance with dissipation (QCM-D) to monitor the changes in layer thickness and viscoelastic properties accompanying multilayer amyloid deposition in situ for the first time. By means of atomic force microscope imaging, an unequivocal correlation is established between the interfacial nucleation and growth of glucagon. brils and the QCM- D response. The combination of the two techniques allows us to study the temporal evolution of the interfacial fibrillation process. We have modeled the QCM-D data using an extension to the Kelvin- Voigt viscoelastic model. Three phases were observed in the. fibrillation process: 1), a rigid multilayer of glucagon monomers forms and slowly rearranges; 2), this multilayer subsequently evolves into a dramatically more viscoelastic layer, containing a polymorphic network of micrometer-long fibrils growing from multiple nucleation sites; and 3), the fibrillar formation effectively stops as a result of the depletion of bulk- phase monomers, although the process can be continued without a lag phase by subsequent addition of fresh monomers. The robustness of the QCM- D technique, consolidated by complementary atomic force microscope studies, should make it possible to combine different components thought to be involved in the plaque formation process and thus build up realistic models of amyloid plaque formation in vitro.