Wang Huan, Kelley Fleurie M, Milovanovic Dragomir, Schuster Benjamin S, Shi Zheng
Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey.
Department of Chemical and Biochemical Engineering, Rutgers University, Piscataway, New Jersey.
Biophys Rep (N Y). 2021 Sep 8;1(1). doi: 10.1016/j.bpr.2021.100011. Epub 2021 Aug 11.
The material properties of biomolecular condensates have been suggested to play important biological and pathological roles. Despite the rapid increase in the number of biomolecules identified that undergo liquid-liquid phase separation, quantitative studies and direct measurements of the material properties of the resulting condensates have been severely lagging behind. Here, we develop a micropipette-based technique that uniquely, to our knowledge, allows quantifications of both the surface tension and viscosity of biomolecular condensates, independent of labeling and surface-wetting effects. We demonstrate the accuracy and versatility of this technique by measuring condensates of LAF-1 RGG domains and a polymer-based aqueous two-phase system. We further confirm our measurements using established condensate fusion and fluorescence recovery after photobleaching assays. We anticipate the micropipette-based technique will be widely applicable to biomolecular condensates and will resolve several limitations regarding current approaches.
生物分子凝聚物的材料特性被认为发挥着重要的生物学和病理学作用。尽管已鉴定出经历液-液相分离的生物分子数量迅速增加，但对所得凝聚物材料特性的定量研究和直接测量却严重滞后。在此，我们开发了一种基于微量移液器的技术，据我们所知，该技术独特地能够独立于标记和表面润湿效应来定量生物分子凝聚物的表面张力和粘度。我们通过测量LAF-1 RGG结构域的凝聚物和基于聚合物的水两相系统来证明该技术的准确性和通用性。我们使用既定的凝聚物融合和光漂白后荧光恢复测定法进一步证实了我们的测量结果。我们预计基于微量移液器的技术将广泛应用于生物分子凝聚物，并将解决当前方法的若干局限性。
