Computational and Single-Molecule Characterization of Kinesin's Power Stroke

驱动蛋白动力冲程的计算和单分子表征

基本信息

批准号：
7357447
负责人：
Wonmuk Hwang
金额：
$ 18.59万
依托单位：
TEXAS ENGINEERING EXPERIMENT STATION
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-04-01 至 2010-03-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): Kinesin is a biped motor protein that walks along microtubule tracks in a cell and performs diverse tasks, including intracellular cargo transport and cell division. To date, it is the smallest known processive motor that directly converts the chemical energy of ATP into mechanical energy. A deeper insight into how kinesin functions is thus not only important for advancing fundamental knowledge of molecular motors, but also critical for developing novel therapeutics against diseases involving impaired intracellular transport. Although past biochemical, biophysical, and structural experiments revealed a significant amount of information about kinesin, the basic mechanism by which it operates as a mechanical amplifier to generate a walking stroke remains unknown. To elucidate the mechanism, it will be critical to develop a synergistic approach combining experimental manipulation of individual kinesin molecules and a computational model based on its atomistic structure. Only through such a combined approach will it be possible to find the molecular physical principle that governs the actual walking motion. Our recent molecular dynamics simulation identified the mechanical element responsible for kinesin's power stroke, which we named the cover strand. It works by assisting kinesin's leg, the neck linker, through forming or breaking a bundle with it depending on kinesin's mechanochemical cycle. Formation of the cover-neck bundle results in a forward conformational bias that generates the power stroke. To validate this experimentally, kinesin mutants missing the cover strand will be constructed and tested using single molecule optical trapping force measurements. At the same time, a computational model of the entire kinesin-microtubule complex will be constructed so that kinesin's whole walking step can be investigated in atomistic detail. Response of the mutant kinesin in the single molecule experiments will be interpreted using computational models. In this way, experiments will be used to refine models, while simulation will be used to interpret experimental data and further design new experiments. Such a tight coupling between experimentation and simulation will provide a clear molecular level mechanistic picture of kinesin motility, upon which a host of other motor proteins will be investigated as our long-term goal. Relevance: Deeper understanding of kinesin motility will enable better control of its behavior, which will lead to novel therapeutics that target kinesin-mediated transport. Our combined approach between computational modeling of macromolecular complexes and single-molecule manipulation experiment will also be a platform upon which a range of subcellular motor processes of biomedical importance will be investigated.

描述（由申请人提供）：驱动蛋白是一种双足运动蛋白，它沿着细胞中的微管轨迹行走并执行多种任务，包括细胞内货物运输和细胞分裂。迄今为止，它是已知最小的可直接将 ATP 化学能转化为机械能的加工电机。因此，更深入地了解驱动蛋白的功能不仅对于推进分子马达的基础知识很重要，而且对于开发针对细胞内运输受损疾病的新疗法也至关重要。尽管过去的生物化学、生物物理和结构实验揭示了有关驱动蛋白的大量信息，但它作为机械放大器产生步行行程的基本机制仍然未知。为了阐明这一机制，开发一种结合单个驱动蛋白分子的实验操作和基于其原子结构的计算模型的协同方法至关重要。只有通过这种综合方法，才有可能找到控制实际行走运动的分子物理原理。我们最近的分子动力学模拟确定了负责驱动蛋白动力冲程的机械元件，我们将其命名为覆盖链。它的工作原理是根据驱动蛋白的机械化学循环，通过形成或打破束来协助驱动蛋白的腿（颈部连接器）。盖颈束的形成导致产生动力冲程的前向构象偏差。为了通过实验验证这一点，将构建缺少覆盖链的驱动蛋白突变体，并使用单分子光学捕获力测量进行测试。同时，将构建整个驱动蛋白-微管复合物的计算模型，以便可以对驱动蛋白的整个行走步骤进行原子细节研究。将使用计算模型解释单分子实验中突变驱动蛋白的响应。这样，实验将用于完善模型，而模拟将用于解释实验数据并进一步设计新的实验。实验和模拟之间的这种紧密耦合将提供驱动蛋白运动的清晰的分子水平机制图，在此基础上，我们将研究许多其他运动蛋白作为我们的长期目标。相关性：对驱动蛋白运动性的更深入了解将能够更好地控制其行为，这将导致针对驱动蛋白介导的运输的新疗法。我们的大分子复合物计算模型和单分子操作实验之间的组合方法也将成为一个平台，在此基础上研究一系列具有生物医学重要性的亚细胞运动过程。

项目成果

期刊论文数量（5）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Force generation in kinesin hinges on cover-neck bundle formation.

驱动蛋白中力的产生取决于盖颈束的形成。

DOI：
10.1016/j.str.2007.11.008
发表时间：
2024-09-13
期刊：
Structure
影响因子：
5.7
作者：
W. Hwang;M. Lang;M. Karplus
通讯作者：
M. Karplus

Kinesin's cover-neck bundle folds forward to generate force.

驱动蛋白的颈盖束向前折叠以产生力。

DOI：
发表时间：
2008-12-09
期刊：
影响因子：
11.1
作者：
Khalil, Ahmad S;Appleyard, David C;Labno, Anna K;Georges, Adrien;Karplus, Martin;Belcher, Angela M;Hwang, Wonmuk;Lang, Matthew J
通讯作者：
Lang, Matthew J

Critical buckling length versus persistence length: what governs biofilament conformation?

临界屈曲长度与持久长度：什么决定生物丝构象？

DOI：
发表时间：
2009-03-20
期刊：
影响因子：
8.6
作者：
Lakkaraju, Sirish Kaushik;Hwang, Wonmuk
通讯作者：
Hwang, Wonmuk

Modulation of elasticity in functionally distinct domains of the tropomyosin coiled-coil.

原肌球蛋白卷曲螺旋功能不同区域的弹性调节。

DOI：
发表时间：
2009-03-01
期刊：
影响因子：
0
作者：
Lakkaraju, Sirish Kaushik;Hwang, Wonmuk
通讯作者：
Hwang, Wonmuk

Dual antagonistic role of motor proteins in fluidizing active networks

运动蛋白在流化活性网络中的双重拮抗作用

DOI：
10.1063/5.0125479
发表时间：
2021-12-21
期刊：
The Journal of chemical physics
影响因子：
0
作者：
Bibi Najma;M. Varghese;Lev Tsidilkovski;Linnea M. Lemma;A. Baskaran;G. Duclos
通讯作者：
G. Duclos