Pearl-Necklace-Like Local Ordering Drives Polypeptide Collapse.
Pearl-Necklace-Like Local Ordering Drives Polypeptide Collapse.
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珍珠项链状局部有序驱动多肽崩溃。
DOI：
10.1021/acs.macromol.9b00562
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发表时间：
2019
期刊：
影响因子：
5.5
通讯作者：
Janke,Wolfhard
中科院分区：
文献类型：
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作者：
Majumder,Suman;Hansmann,UlrichHE;Janke,Wolfhard
多肽骨架的折叠是蛋白质折叠的组成部分。以多聚甘氨酸为探针，研究了蛋白质在水溶液中的非平衡折叠途径。我们发现，崩溃取决于水合作用和肽内相互作用之间的竞争。一旦肽内的货车范德华相互作用占主导地位，链就会沿着非平衡途径塌陷，其特征是形成珍珠项链样的局部簇，作为最终凝结成单个小球的中间体。通过将接触概率描述为沿链沿着的距离的函数来描述这种粗化，我们提取了以线性方式增长的时间依赖性长度尺度。塌缩动力学的特征在于动力学临界指数z = 0.5，远小于非生物聚合物的z = 1-2的值。这种指数的差异是由瞬时形成的链内氢键和本地订购，可能与所观察到的快速折叠时间的蛋白质。
The collapse of the polypeptide backbone is an integral part of protein folding. Using polyglycine as a probe, we explore the nonequilibrium pathways of protein collapse in water. We find that the collapse depends on the competition between hydration effects and intrapeptide interactions. Once intrapeptide van der Waal interactions dominate, the chain collapses along a nonequilibrium pathway characterized by formation of pearl-necklace-like local clusters as intermediates that eventually coagulate into a single globule. By describing this coarsening through the contact probability as a function of distance along the chain, we extract a time-dependent length scale that grows in a linear fashion. The collapse dynamics is characterized by a dynamical critical exponentz≈ 0.5 that is much smaller than the values ofz= 1–2 reported for nonbiological polymers. This difference in the exponents is explained by the instantaneous formation of intrachain hydrogen bonds and local ordering that may be correlated with the observed fast folding times of proteins.