Plotkin S S
Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada.
Biophys J. 2005 Jun;88(6):3762-9. doi: 10.1529/biophysj.104.052548. Epub 2005 Mar 11.
We determine both barrier heights and prefactors for protein folding by applying constraints determined from experimental rate measurements to a Kramers theory for folding rate. The theoretical values are required to match the experimental values at two conditions of temperature and denaturant that induce the same stability. Several expressions for the prefactor in the Kramers rate equation are examined: a random energy approximation, a correlated energy approximation, and an approximation using a single Arrhenius activation energy. Barriers and prefactors are generally found to be large as a result of implementing this recipe, i.e., the folding landscape is cooperative and smooth. Interestingly, a prefactor with a single Arrhenius activation energy admits no formal solution.
我们通过将从实验速率测量中确定的约束应用于折叠速率的克莱默斯理论，来确定蛋白质折叠的势垒高度和预指数因子。理论值需要在两种诱导相同稳定性的温度和变性剂条件下与实验值相匹配。我们研究了克莱默斯速率方程中预指数因子的几种表达式：随机能量近似、相关能量近似以及使用单一阿仑尼乌斯活化能的近似。通过实施此方法，通常会发现势垒和预指数因子都很大，即折叠景观是协同且平滑的。有趣的是，具有单一阿仑尼乌斯活化能的预指数因子不存在形式上的解。
