Institute for X-Ray Physics, University of Göttingen, 37077 Göttingen, Germany.
Lab Chip. 2021 Feb 23;21(4):735-745. doi: 10.1039/d0lc00985g.
Despite the importance for cellular processes, the dynamics of molecular assembly, especially on fast time scales, is not yet fully understood. To this end, we present a multi-layer microfluidic device and combine it with fluorescence fluctuation spectroscopy. We apply this innovative combination of methods to investigate the early steps in assembly of vimentin intermediate filaments (IFs). These filaments, together with actin filaments and microtubules, constitute the cytoskeleton of cells of mesenchymal origin and greatly influence their mechanical properties. We are able to directly follow the two-step assembly process of vimentin IFs and quantify the time scale of the first lateral step to tens of ms with a lag time of below 3 ms. Although demonstrated for a specific biomolecular system here, our method may potentially be employed for a wide range of fast molecular reactions in biological or, more generally, soft matter systems, as it allows for a precise quantification of the kinetics underlying the aggregation and assembly.
尽管分子组装对于细胞过程非常重要，但分子组装的动力学，尤其是在快速时间尺度下的动力学，尚未完全被理解。为此，我们提出了一种多层微流控装置，并将其与荧光波动光谱学相结合。我们应用这种创新的方法组合来研究中间丝（IF）组装的早期步骤。这些细丝与肌动蛋白丝和微管一起构成了间充质来源细胞的细胞骨架，并极大地影响了它们的机械性能。我们能够直接跟踪中间丝（IF）组装的两步过程，并将第一个横向步骤的时间尺度量化到数十毫秒，滞后时间低于 3 毫秒。虽然这里展示的是特定的生物分子体系，但我们的方法可能潜在地适用于生物学或更广泛的软物质体系中的各种快速分子反应，因为它能够精确地量化聚合和组装的动力学。
