Analysis of microtubule guidance in open microfabricated channels coated with the motor protein kinesin
Analysis of microtubule guidance in open microfabricated channels coated with the motor protein kinesin
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DOI：
10.1021/la026155x
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发表时间：
2003-03-04
期刊：
影响因子：
3.9
通讯作者：
Vogel, V
中科院分区：
文献类型：
--
作者：
Clemmens, J;Hess, H;Vogel, V
运动蛋白（如运动蛋白）在细胞中用于沿着确定的丝路径运输细胞内货物。运输系统的成分（即运动蛋白和细丝）可以在合成表面上重建，作为主动运输货物的分子穿梭体。微制造的开放通道在过去已经被用来引导微管被吸附到表面的激酶推动。为了更好地理解引导发生的机制，我们提出了微管沿着直聚氨酯通道1微米深的运输效率的定量测量。我们的分析表明，微管留在通道中的概率作为其行进距离的函数呈指数下降，并且这种特征衰减距离随通道宽度而变化。我们认为微管与侧壁的碰撞是微管逃离通道的关键事件，因此是引导效率的决定因素。为了更好地理解碰撞与行驶距离之间的关系，我们确定了通道宽度对以下因素的影响：(1)微管与侧壁的接近角，(2)碰撞结果（引导或逃脱），以及(3)碰撞之间的距离。还讨论了微管或肌动蛋白丝的物理性质（即长度，弯曲刚度，持续长度）和通道几何形状（宽度，高度）的变化如何描述测量参数。
Motor proteins such as kinesin are used in cells to transport intracellular cargo along defined filament paths. The constituents of the transport system (i.e., motor proteins and filaments) can be reconstructed on synthetic surfaces to serve as molecular shuttles that actively transport cargo. Microfabricated open channels have been used in the past to guide microtubules propelled by kinesin adsorbed to the surface. In an effort to better understand the mechanism by which guidance occurs, we present a quantitative measure of the transport efficiency of microtubules along straight polyurethane channels 1 mum deep. Our analysis shows that the probability of a microtubule remaining in a channel drops exponentially as a function of its travel distance and that this characteristic decay distance varies with channel width. We identify microtubule-sidewall collisions as the key event for microtubule escape from a channel and thus the determinant of guiding efficiency. To better understand the relationship between collisions and travel distance, we determine the effect of channel width on (1) the microtubule approach angle to the sidewall, (2) the collision outcome (guided or escaped), and (3) the distance traveled between collisions. Also discussed is how the physical properties of microtubules or actin filaments (i.e., length, bending stiffness, persistence length) and changes in channel geometry (width, height) can describe measured parameters.