Characteristic temperatures of folding of a small peptide

We perform a generalized-ensemble simulation of a small peptide taking the interactions among all atoms into account. From this simulation we obtain thermodynamic quantities over a wide range of temperatures. In particular, we show that the folding of a small peptide is a multistage process associated with two characteristic temperatures, the collapse temperature T(θ) and the folding temperature T(ƒ). Our results give supporting evidence for the energy landscape picture and funnel concept. These ideas were previously developed in the context of studies of simplified protein models, and here are checked in an all-atom Monte Carlo simulation.

本研究针对一条小肽开展广义系综模拟（generalized-ensemble simulation），将全原子间的相互作用纳入考量。通过该模拟，我们获取了宽温度区间内的热力学参量。尤为关键的是，本研究证实小肽折叠为多阶段过程，对应两个特征温度：塌缩温度（collapse temperature）T(θ)与折叠温度（folding temperature）T(ƒ)。本研究结果为能量景观图景（energy landscape picture）与漏斗概念（funnel concept）提供了支撑证据。上述理念此前基于简化蛋白质模型的研究提出，本研究则通过全原子蒙特卡洛模拟（Monte Carlo simulation）对其进行了验证。