SOLITARY WAVE DYNAMICS AS A MECHANISM FOR EXPLAINING THE INTERNAL MOTION DURING MICROTUBULE GROWTH
SOLITARY WAVE DYNAMICS AS A MECHANISM FOR EXPLAINING THE INTERNAL MOTION DURING MICROTUBULE GROWTH
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DOI：
10.1002/bip.360340114
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发表时间：
1994-01-01
期刊：
影响因子：
2.9
通讯作者：
MAGGIORA, GM
中科院分区：
文献类型：
--
作者：
CHOU, KC;ZHANG, CT;MAGGIORA, GM
微管在生物系统中发挥着多种多样的重要作用，它通常由13根由单个微管蛋白分子形成的近轴向原丝组成。本文建立了一个非线性动力学模型来解释微管组装过程中的内部运动机制。从模型中得出的结果表明，这种内部运动是与孤立波，或扭结，激发的能量从水解的GTP双线箭头指向右GDP在微管解决方案。当扭结向前移动时，参与扭结的单个微管蛋白分子经历可以比作晶格内原子的位错的运动。因此，微管的动力学不稳定性可以通过微管蛋白分子的一系列位错运动来表征。能量估计表明，系统中的扭结具有约0.36-0.44 eV，这非常接近但小于GTP水解释放的0.49 eV的能量。因此，从我们的模型中得到的相关能量与实验观察完全一致;这一发现也表明水解能可能是激发孤波或扭结的原因，导致微管中的微管蛋白错位。动力学非线性、热力学不可逆性以及来自持续源的能量输入意味着微管的生长是典型的耗散过程，并且它们在体内的结构是典型的耗散结构。(C)John Wiley & Sons，Inc.
Microtubules, which play many diverse and important roles in biological systems, are usually made up of 13 nearly axial protofilaments formed from individual tubulin molecules. In this paper, a nonlinear dynamic model has been developed to elucidate the mechanism of the internal motion occurring during the assembly of microtubules. The results derived from the model indicate that such internal motion is associated with a solitary wave, or kink, excited by the energy released from the hydrolysis of GTP double-line arrow pointing right GDP in microtubular solutions. As the kink moves forward, the individual tubulin molecules involved in the kink undergo motions that can be likened to the dislocation of atoms within the crystal lattice. Thus, the dynamic instability of microtubules may be characterized by a series of dislocation motions of the tubulin molecules. An energy estimate shows that a kink in the system possesses about 0.36-0.44 eV, which is quite close to but smaller than the 0.49 eV of energy released from the hydrolysis of GTP. Therefore, the relevant energy derived from our model is fully consistent with experimental observations; this finding also suggests that the hydrolysis energy may be responsible for exciting the solitary wave, or kink, leading to tubulin dislocation in microtubules.Our model, and its intrinsic properties, i.e., dynamic nonlinearity, thermodynamic irreversibility, as well as an energy input from a sustained source, implies that the growth of microtubules is a typical dissipative process and that their structure in vivo is typical of dissipative structures. (C) 1994 John Wiley & Sons, Inc.