Mohanty D, Kolinski A, Skolnick J
Department of Molecular Biology, The Scripps Research Institute, La Jolla, California 92037, USA.
Biophys J. 1999 Jul;77(1):54-69. doi: 10.1016/S0006-3495(99)76872-4.
Entropy Sampling Monte Carlo (ESMC) simulations were carried out to study the thermodynamics of the folding transition in the GCN4 leucine zipper (GCN4-lz) in the context of a reduced model. Using the calculated partition functions for the monomer and dimer, and taking into account the equilibrium between the monomer and dimer, the average helix content of the GCN4-lz was computed over a range of temperatures and chain concentrations. The predicted helix contents for the native and denatured states of GCN4-lz agree with the experimental values. Similar to experimental results, our helix content versus temperature curves show a small linear decline in helix content with an increase in temperature in the native region. This is followed by a sharp transition to the denatured state. van't Hoff analysis of the helix content versus temperature curves indicates that the folding transition can be described using a two-state model. This indicates that knowledge-based potentials can be used to describe the properties of the folded and unfolded states of proteins.
进行了熵采样蒙特卡罗（ESMC）模拟，以在简化模型的背景下研究GCN4亮氨酸拉链（GCN4-lz）折叠转变的热力学。利用计算出的单体和二聚体的配分函数，并考虑单体和二聚体之间的平衡，在一系列温度和链浓度范围内计算了GCN4-lz的平均螺旋含量。GCN4-lz天然态和变性态的预测螺旋含量与实验值相符。与实验结果类似，我们的螺旋含量与温度曲线显示，在天然区域，随着温度升高，螺旋含量有小幅线性下降。随后是向变性态的急剧转变。对螺旋含量与温度曲线进行范特霍夫分析表明，折叠转变可用两态模型描述。这表明基于知识的势可用于描述蛋白质折叠态和未折叠态的性质。
