Steiner Paul J, Williams Ruth J, Hasty Jeff, Tsimring Lev S
BioCircuits Institute, University of California, San Diego, La Jolla, California.
BioCircuits Institute, University of California, San Diego, La Jolla, California; Department of Mathematics, University of California, San Diego, La Jolla, California.
Biophys J. 2016 Sep 6;111(5):1078-87. doi: 10.1016/j.bpj.2016.07.036.
The contrast between the stochasticity of biochemical networks and the regularity of cellular behavior suggests that biological networks generate robust behavior from noisy constituents. Identifying the mechanisms that confer this ability on biological networks is essential to understanding cells. Here we show that queueing for a limited shared resource in broad classes of enzymatic networks in certain conditions leads to a critical state characterized by strong and long-ranged correlations between molecular species. An enzymatic network reaches this critical state when the input flux of its substrate is balanced by the maximum processing capacity of the network. We then consider enzymatic networks with adaptation, when the limiting resource (enzyme or cofactor) is produced in proportion to the demand for it. We show that the critical state becomes an attractor for these networks, which points toward the onset of self-organized criticality. We suggest that the adaptive queueing motif that leads to significant correlations between multiple species may be widespread in biological systems.
生化网络的随机性与细胞行为的规律性之间的对比表明，生物网络能从有噪声的成分中产生稳健的行为。确定赋予生物网络这种能力的机制对于理解细胞至关重要。在这里，我们表明，在某些条件下，广泛类别的酶网络中对有限共享资源的排队会导致一种临界状态，其特征是分子物种之间存在强且长程的相关性。当酶网络的底物输入通量与其最大处理能力相平衡时，该酶网络就会达到这种临界状态。然后，我们考虑具有适应性的酶网络，即当有限资源（酶或辅因子）按其需求比例产生时的情况。我们表明，临界状态成为这些网络的一个吸引子，这指向自组织临界性的开始。我们认为，导致多个物种之间产生显著相关性的适应性排队基序可能在生物系统中广泛存在。
