Glyakina Anna V, Balabaev Nikolai K, Galzitskaya Oxana V
Institute of Mathematical Problems of Biology, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia.
Open Biochem J. 2009 Nov 23;3:66-77. doi: 10.2174/1874091X00903010066.
We have studied the mechanical properties of the immunoglobulin-binding domain of protein G at the atomic level under stretching at constant velocity using molecular dynamics simulations. We have found that the unfolding process can occur either in a single step or through intermediate states. Analysis of the trajectories from the molecular dynamic simulations showed that the mechanical unfolding of the immunoglobulin-binding domain of protein G is triggered by the separation of the terminal beta-strands and the order in which the secondary-structure elements break is practically the same in two- and multi-state events and at the different extension velocities studied. It is seen from our analysis of 24 trajectories that the theoretical pathway of mechanical unfolding for the immunoglobulin-binding domain of protein G does not coincide with that proposed in denaturant studies in the absence of force.
我们使用分子动力学模拟，在恒速拉伸条件下，从原子水平研究了蛋白G免疫球蛋白结合结构域的力学性质。我们发现，展开过程既可以一步完成，也可以通过中间状态发生。对分子动力学模拟轨迹的分析表明，蛋白G免疫球蛋白结合结构域的力学展开是由末端β链的分离引发的，在双态和多态事件中，以及在所研究的不同延伸速度下，二级结构元件断裂的顺序实际上是相同的。从我们对24条轨迹的分析可以看出，蛋白G免疫球蛋白结合结构域力学展开的理论途径与在无外力变性剂研究中提出的途径不一致。
