文章基本信息

标题：Molecular dynamics of an α-helical polypeptide: Temperature dependence and deviation from harmonic behavior
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作者：Ronald M. Levy ; David Perahia ; Martin Karplus 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1982
卷号：79
期号：4
页码：1346-1350
DOI：10.1073/pnas.79.4.1346
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The mean square amplitudes of atomic fluctuations for a polypeptide (decaglycine) -helix evaluated from molecular dynamics simulations at seven temperatures between 5 and 300 K are compared with analytic harmonic results and with experimental values. Above 100 K the harmonic approximation significantly underestimates the amplitudes of the displacements. Analysis of the time dependence of the fluctuations shows that low-frequency modes (<75 cm-1) dominate the atomic fluctuations and that there is a contribution with a very long relaxation time (>10 ps). Quantum corrections to the amplitude of the fluctuations are found to be small above 50 K. The mean square amplitudes obtained from the molecular dynamics simulations are compared with the values derived from x-ray temperature (Debye-Waller) factors for metmyoglobin (80, 250, and 300 K) and ferrocytochrome c (300 K).
关键词：protein dynamics ; temperature factor ; quantum corrections ; fluctuations ; normal modes