Bacterial Amyloids: Biogenesis and Biomaterials
Bacterial Amyloids: Biogenesis and Biomaterials
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DOI：
10.1007/978-981-13-9791-2_4
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发表时间：
2019-01-01
期刊：
影响因子：
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通讯作者：
Otzen, Daniel E.
中科院分区：
文献类型：
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作者：
Christensen, Line Friis Bakmann;Schafer, Nicholas;Otzen, Daniel E.
功能性淀粉样蛋白（FuBA）由所有细菌种类的很大一部分产生，与神经退行性疾病中看到的病理性淀粉样蛋白相比，它代表了稳定淀粉样蛋白折叠的建设性利用。当组装成淀粉样蛋白时，FuBA异常坚固，可以抵抗大多数化学物质，包括变性剂和SDS。用途包括加强细菌生物膜，细胞间通讯，细胞壁建设，甚至细菌战。生物发生受到严格的时空控制，这要归功于大肠杆菌、假单胞菌和其他经过充分研究的细菌的一个简单而有效的分泌系统，其中包括一种主要的淀粉样蛋白成分，它在周质中保持展开，这要归功于伴侣蛋白，通过孔蛋白穿过外膜，并通过核蛋白和可能的其他辅助蛋白锚定在细胞表面。在这些系统中，淀粉样蛋白的形成是通过不完全重复序列促进的，但其他进化上不相关的蛋白质要么没有或只有部分保守的重复序列，要么只是由具有多种结构作用的小肽组成。这使得生物信息学分析具有挑战性，尽管从病理性淀粉样蛋白研究中开发的复杂淀粉样蛋白预测工具以及对淀粉样蛋白进一步鉴定的稳步增加将加强基因组数据挖掘。当将淀粉样蛋白成分的优化自组装特性与具有不同结合特性的肽或表面反应蛋白结合物相结合时，功能性淀粉样蛋白代表了具有新特性的健壮且可生物降解材料的有趣来源。通过共同培养产生不同类型淀粉样蛋白的细菌也可以获得复杂的模式，而淀粉样蛋白包涵体可能导致缓释纳米颗粒。
Functional amyloid (FuBA) is produced by a large fraction of all bacterial species and represents a constructive use of the stable amyloid fold, in contrast to the pathological amyloid seen in neurodegenerative diseases. When assembled into amyloid, FuBA is unusually robust and withstands most chemicals including denaturants and SDS. Uses include strengthening of bacterial biofilms, cell-to-cell communication, cell wall construction and even bacterial warfare. Biogenesis is under tight spatio-temporal control, thanks to a simple but efficient secretion system which in E. coli, Pseudomonas and other well-studied bacteria includes a major amyloid component that is kept unfolded in the periplasm thanks to chaperones, threaded through the outer membrane via a pore protein and anchored to the cell surface through a nucleator and possibly other helper proteins. In these systems, amyloid formation is promoted through imperfect repeats, but other evolutionarily unrelated proteins either have no or only partially conserved repeats or simply consist of small peptides with multiple structural roles. This makes bioinformatics analysis challenging, though the sophisticated amyloid prediction tools developed from research in pathological amyloid together with the steady increase in identification of further examples of amyloid will strengthen genomic data mining. Functional amyloid represents an intriguing source of robust yet biodegradable materials with new properties, when combining the optimized self-assembly properties of the amyloid component with e.g. peptides with different binding properties or surface-reactive protein binders. Sophisticated patterns can also be obtained by co-incubating bacteria producing different types of amyloid, while amyloid inclusion bodies may lead to slow-release nanopills.