德国马克斯·普朗克研究所Frank Jülicher研究团队发现凝聚蛋白质老化后呈现为麦克斯韦流体。 该项研究成果发表在2020年12月11日出版的《科学》。

凝聚蛋白质是一种复杂的流体，可以随时间改变其物质的流变性。然而，这些流体合适的流变学描述仍然缺失。

该文中，研究人员使用基于激光镊子的主动流变学和基于微珠的被动流变学来表征体外蛋白质聚合物的时间依赖特性。对于不同的蛋白质，凝聚蛋白质经不同老化时间均表现为粘弹性麦克斯韦流体。它们的粘度随老化时间的增加而显著增加，而弹性模量变化不大。在早期和晚期，电子显微镜下未发现明显的结构差异。

因此得出结论，蛋白质凝聚物可以是软玻璃状材料，具有与老化时间相关的材料属性，研究人员称之为麦克斯韦玻璃。研究人员讨论了玻璃化行为对细胞生物化学调节的可能优势。

附：英文原文

Title: Protein condensates as aging Maxwell fluids

Author: Louise Jawerth, Elisabeth Fischer-Friedrich, Suropriya Saha, Jie Wang, Titus Franzmann, Xiaojie Zhang, Jenny Sachweh, Martine Ruer, Mahdiye Ijavi, Shambaditya Saha, Julia Mahamid, Anthony A. Hyman, Frank Jülicher

Issue&Volume: 2020/12/11

Abstract: Protein condensates are complex fluids that can change their material properties with time. However, an appropriate rheological description of these fluids remains missing. We characterize the time-dependent material properties of in vitro protein condensates using laser tweezer–based active and microbead-based passive rheology. For different proteins, the condensates behave at all ages as viscoelastic Maxwell fluids. Their viscosity strongly increases with age while their elastic modulus varies weakly. No significant differences in structure were seen by electron microscopy at early and late ages. We conclude that protein condensates can be soft glassy materials that we call Maxwell glasses with age-dependent material properties. We discuss possible advantages of glassy behavior for modulation of cellular biochemistry.

DOI: 10.1126/science.aaw4951

Source: https://science.sciencemag.org/content/370/6522/1317