A statistical mechanical model for β-hairpin kinetics
A statistical mechanical model for β-hairpin kinetics
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DOI：
10.1073/pnas.95.11.5872
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发表时间：
1998-05-26
影响因子：
11.1
通讯作者：
Eaton, WA
中科院分区：
文献类型：
--
作者：
Muñoz, V;Henry, ER;Eaton, WA
了解蛋白质二级结构的形成机制是蛋白质折叠之谜的重要组成部分。在这里，我们描述了一个简单的统计力学模型来形成β-发夹，这是反平行的β-褶皱薄板的最小结构元素。该模型准确地描述了16个残基的β-发夹形成肽的热力学和动力学行为，成功地解释了它的两态行为和折叠的表观负活化能，该模型根据骨架构象对结构进行分类，由15对二面角定义，并通过只考虑120个具有连续延伸的天然主链二面角对的结构来进一步简化。通过与包括2(15)个可能构象和15×2(15)个可能动力学转变的更完整模型的比较，对这种单一序列近似进行了检验。最后，我们使用该模型来预测β-发夹多肽的几个变体的平衡展开曲线和动力学。
Understanding the mechanism of protein secondary structure formation is an essential part of the protein-folding puzzle. Here, we describe a simple statistical mechanical model for the formation of a beta-hairpin, the minimal structural element of the antiparallel beta-pleated sheet. The model accurately describes the thermodynamic and kinetic behavior of a 16-residue, beta-hairpin-forming peptide, successfully explaining its two-state behavior and apparent negative activation energy for folding, The model classifies structures according to their backbone conformation, defined by 15 pairs of dihedral angles, and is further simplified by considering only the 120 structures with contiguous stretches of native pairs of backbone dihedral angles. This single sequence approximation is tested by comparison with a more complete model that includes the 2(15) possible conformations and 15 x 2(15) possible kinetic transitions. Finally, we use the model to predict the equilibrium unfolding curves and kinetics for several variants of the beta-hairpin peptide.