基内辛走路时会交手交手
Ahmet Yildiz1, Michio Tomishige, Ronald D Vale
1Center for Biophysics and Computational Biology, University of Illinois, Urbana-Champaign, IL 61801, USA.
Science (New York, N.Y.)
|December 20, 2003
概括
素运动蛋白使用手对手机制移动,而不是英寸模型. 单个kinesin头采取大步骤,交替停顿,支持这个模型.
科学领域:
- 分子运动功能的分子运动功能.
- 细胞运输机制的细胞运输机制.
- 蛋白质运动的生物物理学
背景情况:
- 素是一种重要的运动蛋白,它沿着微管道运输货物.
- 基因素的精确步骤机制 (手对手与英寸相比) 是一个长期的争论.
- 了解素的运动对于细胞生物学和疾病研究至关重要.
研究的目的:
- 为了阐明基因素运动蛋白的步骤机制.
- 为了区分手对手和英寸模型中的kinesin运动性.
- 为了提供对个体运动头部运动的高分辨率数据.
主要方法:
- 单分子光显微镜被用来标记和跟踪kinesin头.
- 为了精确的定位,一个Cy3光体被附着在一个单一的kinesin头上.
- 在每个步骤之前和之后,高分辨率跟踪在2纳米范围内确定染料位置.
主要成果:
- 观察到单个kinesin头采取17.3±3.3nm的步骤.
- 动力分析显示,这些大步骤与0nm步骤 (暂停) 交替.
- 观察到的渐进模式强烈支持一个手对手机制.
结论:
- 这些发现提供了强有力的证据,证明了素运动中的交接机制.
- 结果驳斥了英寸模型对素沿微管道的运动.
- 在ATP结合暂停期间,素可能保持对微管的双头附着.
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