Molecular spiders with memory
Molecular spiders with memory
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DOI：
10.1103/physreve.76.021121
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发表时间：
2007-08-01
影响因子：
2.4
通讯作者：
Krapivsky, P. L.
中科院分区：
文献类型：
--
作者：
Antal, Tibor;Krapivsky, P. L.
合成生物分子蜘蛛的“腿”由单链DNA片段组成，可以在表面上移动，表面上也覆盖着与腿DNA互补的单链DNA片段。在实验中，当一条腿第一次从表面的一段分离时，它会改变该段，腿随后会更弱地与这些改变的段结合。受这些实验的启发，我们研究了蜘蛛沿着沿着一维基底移动，其腿离开新访问的网站比重访网站的速度慢。对于随机行走（单腿蜘蛛），减速不会影响长时间行为。然而，对于双足蜘蛛来说，减速会产生一种有效的偏向未访问的网站，蜘蛛的行为与兴奋的步行相似。令人惊讶的是，蜘蛛在新站点上的减速增加了扩散系数，并加速了访问站点数量的增长。
Synthetic biomolecular spiders with "legs" made of single-stranded segments of DNA can move on a surface which is also covered by single-stranded segments of DNA complementary to the leg DNA. In experimental realizations, when a leg detaches from a segment of the surface for the first time it alters that segment, and legs subsequently bind to these altered segments more weakly. Inspired by these experiments, we investigate spiders moving along a one-dimensional substrate, whose legs leave newly visited sites at a slower rate than revisited sites. For a random walk (one-leg spider), the slowdown does not affect the long time behavior. For a bipedal spider, however, the slowdown generates an effective bias toward unvisited sites, and the spider behaves similarly to the excited walk. Surprisingly, the slowing down of the spider at new sites increases the diffusion coefficient and accelerates the growth of the number of visited sites.