Visualization and Classification of Amyloid Supramolecular Assemblies
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- 作者：Hisashi Yagi ; Tadato Ban ; Kenichi Morigaki ; Hironobu Naiki ; Yuji Goto
- 刊名：Biochemistry
- 出版年：2007
- 出版时间：December 25, 2007
- 年：2007
- 卷：46
- 期：51
- 页码：15009 - 15017
- 全文大小：1651K
- 年卷期：v.46,no.51(December 25, 2007)
- ISSN：1520-4995
文摘
Deposition of amyloid (A) fibrils has been suggested to play a central role in Alzheimer'sdisease. In clarifying the mechanism by which fibrils form and moreover in developing new treatmentsfor amyloidosis, direct observation is important. Focusing on the interactions with surfaces at the earlystages, we studied the spontaneous formation of A(1-40) fibrils on quartz slides, monitored by totalinternal reflection fluorescence microscopy combined with thioflavin T, an amyloid-specific fluorescencedye. Self-assembly of A(1-40), accelerated by a low concentration of sodium dodecyl sulfate, producedvarious remarkable amyloid assemblies. Densely packed spherulitic structures with radial fibril growthwere typically observed. When the packing of fibrils was coarse, extremely long fibrils often protrudedfrom the spherulitic cores. In other cases, a large number of wormlike fibrils were formed. Transmissionelectron microscopy and atomic force microscopy revealed relatively short and straight fibrillar blocksassociated laterally without tight interaction, leading to random-walk-like fibril growth. These resultssuggest that, during spontaneous fibrillation, the nucleation occurring in contact with surfaces is easilyaffected by environmental factors, creating various types of nuclei, and hence variations in amyloidmorphology. A taxonomy of amyloid supramolecular assemblies will be useful in clarifying the structure-function relationship of amyloid fibrils.