Department of Physics, The University of Maine , 5709 Bennett Hall, Orono, Maine 04469-5709, United States.
ACS Nano. 2014 Dec 23;8(12):11917-24. doi: 10.1021/nn507039b.
Active enzymes diffuse more rapidly than inactive enzymes. This phenomenon may be due to catalysis-driven conformational changes that result in "swimming" through the aqueous solution. Recent additional work has demonstrated that active enzymes can undergo chemotaxis toward regions of high substrate concentration, whereas inactive enzymes do not, and, further, that active enzymes immobilized at surfaces can directionally pump liquids. In this Perspective, I will discuss these phenomena in light of Purcell's work on directed motion at low Reynold's number and in the context of microscopic reversibility. The conclusions suggest that a deep understanding of catalytically driven enhanced diffusion of enzymes and related phenomena can lead toward a general organizing principle for the design, characterization, and operation of molecular machines.
活性酶比非活性酶扩散得更快。这种现象可能是由于催化驱动的构象变化，导致它们在水溶液中“游动”。最近的进一步研究表明，活性酶可以向高底物浓度区域进行趋化运动，而非活性酶则不能，而且，进一步的研究表明，固定在表面的活性酶可以定向泵送液体。在这篇观点文章中，我将根据珀塞尔（Purcell）在低雷诺数下定向运动的工作以及微观可逆性的背景来讨论这些现象。结论表明，深入了解酶的催化驱动增强扩散及相关现象，可以为分子机器的设计、表征和操作提供一个普遍的组织原则。
