Neher Richard A, Möbius Wolfram, Frey Erwin, Gerland Ulrich
Arnold Sommerfeld Center for Theoretical Physics (ASC) and Center for Nanoscience (CeNS), LMU Munich, Theresienstrasse 37, 80333 Munich, Germany.
Phys Rev Lett. 2007 Oct 26;99(17):178101. doi: 10.1103/PhysRevLett.99.178101. Epub 2007 Oct 22.
Conformational transitions in macromolecular complexes often involve the reorientation of leverlike structures. Using a simple theoretical model, we show that the rate of such transitions is drastically enhanced if the lever is bendable, e.g., at a localized hinge. Surprisingly, the transition is fastest with an intermediate flexibility of the hinge. In this intermediate regime, the transition rate is also least sensitive to the amount of "cargo" attached to the lever arm, which could be exploited by molecular motors. To explain this effect, we generalize the Kramers-Langer theory for multidimensional barrier crossing to configuration-dependent mobility matrices.
大分子复合物中的构象转变通常涉及类似杠杆结构的重新定向。通过一个简单的理论模型，我们表明，如果杠杆是可弯曲的，例如在局部铰链处，这种转变的速率会急剧提高。令人惊讶的是，在铰链具有中等柔韧性时，转变速度最快。在这种中间状态下，转变速率对附着在杠杆臂上的“货物”量也最不敏感，分子马达可以利用这一点。为了解释这种效应，我们将用于多维势垒穿越的克拉默斯 - 兰格理论推广到依赖于构型的迁移率矩阵。
