期刊
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
卷 104, 期 40, 页码 15729-15734出版社
NATL ACAD SCIENCES
DOI: 10.1073/pnas.0707322104
关键词
density functional theory calculation; peptide folding; TrpZip2; ultrafast infrared spectroscopy
A light-switchable peptide is transformed with ultrashort pulses from a beta-hairpin to an unfolded hydrophobic cluster and vice versa. The structural changes are monitored by mid-IR probing. Instantaneous normal mode analysis with a Hamiltonian combining density functional theory with molecular mechanics is used to interpret the absorption transients. Illumination of the beta-hairpin state triggers an unfolding reaction that visits several intermediates and reaches the unfolded state within a few nanoseconds. In this unfolding reaction to the equilibrium hydrophobic cluster conformation, the system does not meet significant barriers on the free-energy surface. The reverse folding process takes much longer because it occurs on the time scale of 30 mu s. The folded state has a defined structure, and its formation requires an extended search for the correct hydrogen-bond pattern of the beta-strand.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据