IEEE Trans Nanobioscience. 2022 Jul;21(3):439-444. doi: 10.1109/TNB.2022.3170562. Epub 2022 Jun 30.
Myosin and kinesin are biomolecular motors found in living cells. By propelling their associated cytoskeletal filaments, these biomolecular motors facilitate force generation and material transport in the cells. When extracted, the biomolecular motors are promising candidates for in vitro applications such as biosensor devices, on account of their high operating efficiency and nanoscale size. However, during integration into these devices, some of the motors become defective due to unfavorable adhesion to the substrate surface. These defective motors inhibit the motility of the cytoskeletal filaments which make up the molecular shuttles used in the devices. Difficulties in controlling the fraction of active and defective motors in experiments discourage systematic studies concerning the resilience of the molecular shuttle motility against the impedance of defective motors. Here, we used mathematical modelling to systematically examine the resilience of the propulsion by these molecular shuttles against the impedance of the defective motors. The model showed that the fraction of active motors on the substrate is the essential factor determining the resilience of the molecular shuttle motility. Approximately 40% of active kinesin or 80% of active myosin motors are required to constitute continuous gliding of molecular shuttles in their respective substrates. The simplicity of the mathematical model in describing motility behavior offers utility in elucidating the mechanisms of the motility resilience of molecular shuttles.
肌球蛋白和驱动蛋白是存在于活细胞中的生物分子马达。这些生物分子马达通过推动与其相关的细胞骨架丝，促进细胞内的力产生和物质运输。当这些生物分子马达被提取出来时，由于其高操作效率和纳米级尺寸，它们是生物传感器等体外应用的有前途的候选者。然而，在将这些马达集成到这些设备中时，由于与基底表面的不利粘附，一些马达会出现缺陷。这些有缺陷的马达会抑制构成设备中分子梭的细胞骨架丝的运动。由于实验中难以控制活性和缺陷马达的比例，因此对分子梭运动的弹性抵抗缺陷马达的阻抗的系统性研究受到阻碍。在这里，我们使用数学建模来系统地研究这些分子梭的推进弹性抵抗缺陷马达的阻抗。该模型表明，基底上的活性马达的比例是决定分子梭运动弹性的关键因素。大约 40%的活性驱动蛋白或 80%的活性肌球蛋白马达需要在各自的基底上构成分子梭的连续滑行。该数学模型在描述运动行为方面的简单性为阐明分子梭运动弹性的机制提供了实用性。
