Bending dynamics of fluctuating biopolymers probed by automated high-resolution filament tracking
Bending dynamics of fluctuating biopolymers probed by automated high-resolution filament tracking
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DOI：
10.1529/biophysj.106.096966
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发表时间：
2007-07-01
影响因子：
3.4
通讯作者：
Weitz, David A.
中科院分区：
文献类型：
--
作者：
Brangwynne, Clifford P.;Koenderink, Gijsje H.;Weitz, David A.
显微镜下的图像。生物聚合物包含了大量关于其基本机制和动力学的信息。然而，这些信息的成功提取需要精确的定位。从数以千计的嘈杂图像中哀叹位置和形状。在这里，我们提出了一种新的、简单但健壮的、具有亚像素精度的自动图像分析算法，以高空间和时间分辨率仔细测量了丝状(F-)肌动蛋白和微管在热平衡时的弯曲动力学。我们。和那纤细的肌动蛋白。悲歌的持续长度类似于17微米，并显示出Q(-4)相关的弛豫谱，正如粘性阻力所预期的那样。微管的持续长度为几毫米；有趣的是，微管总长度和硬度之间存在着很小的相关性，较短的细丝看起来更柔软。然而，我们表明，这种相关性原则上可以由必须仔细考虑的内在测量噪声引起。微管弯曲的动力学行为也比F-肌动蛋白更复杂，反映了它们的高阶结构。这些结果强调了光学显微镜技术在研究生物聚合物的力学和动力学方面的能力和局限性。
Microscope images of. uctuating biopolymers contain a wealth of information about their underlying mechanics and dynamics. However, successful extraction of this information requires precise localization of. lament position and shape from thousands of noisy images. Here, we present careful measurements of the bending dynamics of filamentous ( F-) actin and microtubules at thermal equilibrium with high spatial and temporal resolution using a new, simple but robust, automated image analysis algorithm with subpixel accuracy. We. nd that slender actin. laments have a persistence length of similar to 17 mu m, and display a q(-4) -dependent relaxation spectrum, as expected from viscous drag. Microtubules have a persistence length of several millimeters; interestingly, there is a small correlation between total microtubule length and rigidity, with shorter filaments appearing softer. However, we show that this correlation can arise, in principle, from intrinsic measurement noise that must be carefully considered. The dynamic behavior of the bending of microtubules also appears more complex than that of F-actin, reflecting their higher-order structure. These results emphasize both the power and limitations of light microscopy techniques for studying the mechanics and dynamics of biopolymers.