驱动马达力学化学耦合机制研究进展

Advances in the mechanism of mechanochemical coupling of kinesin

驱动蛋白是细胞内重要的输运机器,属于平动分子马达.它有两个主要特征,其一是持续性,马达的两个头部在交替步行时至少有一头保持与微管吸附,因此它能沿微管长距离步进而不脱轨;另一个特征是马达的力学过程和化学过程是紧耦合的,即马达每前进一步消耗一个三磷酸腺苷.上述两个特征要求两个头部的核苷化学态及其与微管的相互作用需通过某个机构来协调统一,其中的核心问题是力学化学耦合机制,这也是所有化学驱动的分子马达的关键问题.得益于单分子实验技术和分子动力学模拟技术的发展,驱动马达力学化学耦合机制的研究在最近十年取得了重大突破.本文重点从运动学、动力学、协同机制和发力机制等方面介绍驱动马达基础研究的进展及面临的问题.

Kinesin is one of the most important linear motors for intracellular transport.It has two main features.One is its persistence： at least one head is attached to the microtubule during stepping,so that it can move a long distance before detaching.Another feature is the tight mechanochemical coupling： it consumes one adenosine-triphosphate for each step.Therefore,there should be a mechanism responsible for the coordination of the two heads to achieve the high persistence and tight coupling.The underlying mechanism is the mechanochemical coupling,which is the basic issue for all chemical-driven molecular motors.Owing to the developments of single-molecule experiments and molecular dynamics simulations,a breakthrough in the coupling mechanism has been made in recent decades.In this article,we review the progress of the relevant researches from the perspective of kinematics,energetics,coordination of two heads and force generating mechanism.We also present a personal perspective on the future studies of kinesin.