Molecular crowding facilitates assembly of spidroin-like proteins through phase separation
Molecular crowding facilitates assembly of spidroin-like proteins through phase separation
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DOI：
10.1016/j.eurpolymj.2018.10.010
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发表时间：
2019-03-01
影响因子：
6
通讯作者：
Aranko, A. Sesilja
中科院分区：
文献类型：
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作者：
Lemetti, Laura;Hirvonen, Sami-Pekka;Aranko, A. Sesilja
深入了解将分散的生物聚合物转化为有序结构的过程，如可溶的蜘蛛蛋白和蜘蛛丝线，对于试图了解它们的生物学功能和模仿它们的独特性质至关重要。其中一个过程是液-液相分离，它可以作为分子组装的中间步骤。我们已经证明，在很高的蛋白质浓度(>；200gl(-1))下发生的自凝聚步骤对于工程三嵌段丝状分子的纤维组装至关重要。在这项研究中，我们证明了拥挤剂的加入使凝聚发生的浓度降低了近两个数量级。通过添加聚集剂诱导的凝聚体在纤维形成方面具有功能，并且聚集剂似乎仅通过增加蛋白质的有效浓度来影响这一过程。此外，较低浓度下的诱导使我们能够研究体系的热力学，这为我们提供了对凝聚机制的见解。我们认为，这种方法对于一般生物凝聚系统的研究是有价值的。
Gaining insights into the processes that transform dispersed biopolymers into well-ordered structures, such as soluble spidroin-proteins to spider silk threads, is essential for attempts to understand their biological function and to mimic their unique properties. One of these processes is liquid-liquid phase separation, which can act as an intermediate step for molecular assembly. We have shown that a self-coacervation step that occurs at a very high protein concentration (> 200 gl(-1)) is crucial for the fiber assembly of an engineered triblock silk-like molecule. In this study, we demonstrate that the addition of a crowding agent lowers the concentration at which coacervation occurs by almost two orders of magnitude. Coacervates induced by addition of a crowding agent are functional in terms of fiber formation, and the crowding agent appears to affect the process solely by increasing the effective concentration of the protein. Furthermore, induction at lower concentrations allows us to study the thermodynamics of the system, which provides insights into the coacervation mechanism. We suggest that this approach will be valuable for studies of biological coacervating systems in general.