VanDelinder Virginia, Sickafoose Ian, Imam Zachary I, Ko Randy, Bachand George D
Center for Integrated Nanotechnologies, Sandia National Laboratories Albuquerque NM USA
RSC Adv. 2020 Nov 24;10(70):42810-42815. doi: 10.1039/d0ra08148e. eCollection 2020 Nov 23.
The gliding motility of microtubule filaments has been used to study the biophysical properties of kinesin motors, as well as being used in a variety of nanotechnological applications. While microtubules are generally stabilized with paclitaxel (Taxol®), osmolytes such as polyethylene glycol (PEG) and trimethylamine -oxide (TMAO) are also able to inhibit depolymerization over extended periods of time. High concentrations of TMAO have also been reported to reversibly inhibit kinesin motility of paclitaxel-stabilized microtubules. Here, we examined the effects of the osmolytes PEG, TMAO, and glycerol on stabilizing microtubules during gliding motility on kinesin-coated substrates. As previously observed, microtubule depolymerization was inhibited in a concentration dependent manner by the addition of the different osmolytes. Kinesin-driven motility also exhibited concentration dependent effects with the addition of the osmolytes, specifically reducing the velocity, increasing rates of pinning, and altering trajectories of the microtubules. These data suggest that there is a delicate balance between the ability of osmolytes to stabilize microtubules without inhibiting motility. Overall, these findings provide a more comprehensive understanding of how osmolytes affect the dynamics of microtubules and kinesin motors, and their interactions in crowded environments.
微管丝的滑动运动已被用于研究驱动蛋白马达的生物物理特性，以及用于各种纳米技术应用中。虽然微管通常用紫杉醇（泰素®）来稳定，但诸如聚乙二醇（PEG）和三甲胺氧化物（TMAO）等渗透溶质也能够在较长时间内抑制解聚。据报道，高浓度的TMAO还能可逆地抑制紫杉醇稳定的微管的驱动蛋白运动。在此，我们研究了渗透溶质PEG、TMAO和甘油在驱动蛋白包被的底物上滑动运动期间对稳定微管的影响。如先前观察到的，通过添加不同的渗透溶质，微管解聚以浓度依赖性方式受到抑制。添加渗透溶质后，驱动蛋白驱动的运动也表现出浓度依赖性效应，具体表现为降低速度、增加固定速率以及改变微管的轨迹。这些数据表明，在渗透溶质稳定微管而不抑制运动的能力之间存在微妙的平衡。总体而言，这些发现为渗透溶质如何影响微管和驱动蛋白马达的动力学及其在拥挤环境中的相互作用提供了更全面的理解。
