【作者】 徐丽；

【导师】 薛康；

【作者基本信息】 东北师范大学 ， 理论物理， 2006， 硕士

【摘要】 自从上世纪60年代Anfinsen和他的合作者根据核糖核酸酶可逆伸展与重折叠的研究提出蛋白质折叠过程在热力学稳定方面获得的增益是控制蛋白质在体外正确折叠的驱动力以来,关于蛋白质折叠的动力学和热力学研究取得了很大的进展,特别是Wolynes所建立的能量形貌图理论对生物物理学的蛋白质折叠问题提供了强有力的理论模型。从上个世纪90年代以来,人们在蛋白质折叠和结合的动力学和热力学的研究方面取得了重要的进展,并给出了很多新的物理理解和理论结果。 本文探索在二维和三维蛋白质折叠结合情况下影响蛋白质折叠和结合速度的原因。研究肽链长度对蛋白质折叠和结合速度的影响。研究不同折叠结合能量差和能量半宽对蛋白质折叠和结合速度的影响。探索不同温度下蛋白质折叠和结合速度的变化。将不同温度下蛋白质折叠和结合速度的函数比较,发现其规律性。并推导了三维蛋白质折叠和结合的自由能公式。 通过讨论蛋白质折叠速度随时间的演化情况,我们发现在蛋白质折叠和结合有个特别温度,在这个温度蛋白质折叠结合的速度最快,达到天然状态的时间最短。低于这个温度,蛋白质动能越来越小,达到天然状态的时间越来越长,这是由于蛋白质极易陷入局域最小点。高于这个温度,蛋白质的动能越来越大,所以它越来越不稳定,于是达到天然状态的时间也越来越长。这些结果在实验中都得到了很好的验证,这就是本文的意义所在。更多还原

【Abstract】 Since Anfinsen and his co-workers brought forward the plus of the stability of thermodynamics is the right folding drive in the protein folding process basis on the study of the reversible ribotide-enzyme stretch and refold in 1960s, the investigation on the study of kinetics and thermodynamics of protein folding and binding have been greatly promoted. Especially the theory of the energy landscapes that were established by P. G Wolynes offered a powerful theory model for protein folding and binding in biophysics. People have made great progress on kinetics and thermodynamics of protein folding and binding since 1990s, and have given new physics understanding and theoretical results^[1-5].In this paper, we study the influence on the rate of protein folding and binding both in two dimension and three dimension. We study the rate of protein folding and binding at different temperature, different folding energy and different length of protein. Then we find the rule of kinetics and thermodynamics of protein folding and binding. What’s more, we formulate the expression of the free energy of three dimension.Through studying the evolution of protein folding and binding probability with time, we find that there is an optimal temperature. At this temperature, the rate of protein folding and binding is the fastest of all, and the time of the system reaching its native state is the shortest. As the temperature increases, the proteins become less and less stable, and the non-native unfolding and binding states are more and more preferred. Therefore the time it takes to reach the native state is longer. On the other hand, as the temperature decreases, the time it takes to reach the native folding-binding state is also longer. This is because it is more and more likely that the protein will be trapped into some low-lying energy states. This phenomenon was observed in many experiments. It was proved that the energy landscape is very useful in rationalizing many details of the folding phenomenon again. It will help design experiments too. This is just about the meaning of the paper.更多还原