Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, México, DF México.
J Chem Phys. 2011 Aug 7;135(5):055107. doi: 10.1063/1.3624334.
Brownian ratchets have recently been considered as models to describe the ability of certain systems to locate very specific states in multidimensional configuration spaces. This directional process has particularly been proposed as an alternative explanation for the protein folding problem, in which the polypeptide is driven toward the native state by a multidimensional Brownian ratchet. Recognizing the relevance of robustness in biological systems, in this work we analyze such a property of Brownian ratchets by pushing to the limits all the properties considered essential to produce directed transport. Based on the results presented here, we can state that Brownian ratchets are able to deliver current and locate funnel structures under a wide range of conditions. As a result, they represent a simple model that solves the Levinthal's paradox with great robustness and flexibility and without requiring any ad hoc biased transition probability. The behavior of Brownian ratchets shown in this article considerably enhances the plausibility of the model for at least part of the structural mechanism behind protein folding process.
布朗棘轮最近被认为是描述某些系统在多维构型空间中定位非常特定状态的能力的模型。这种定向过程特别被提出作为蛋白质折叠问题的另一种解释，其中多肽通过多维布朗棘轮被驱动到天然状态。认识到生物系统中稳健性的相关性，在这项工作中，我们通过推动所有被认为对产生定向传输至关重要的特性的极限来分析布朗棘轮的这种特性。基于这里提出的结果，我们可以说布朗棘轮能够在广泛的条件下输送电流并定位漏斗结构。因此，它们代表了一个简单的模型，该模型以极大的稳健性和灵活性解决了莱文塔尔悖论，而无需任何特殊的有偏向的跃迁概率。本文中展示的布朗棘轮的行为极大地提高了该模型的合理性，至少对于蛋白质折叠过程背后的结构机制的一部分是如此。
