Secondary structure conformations and long range electronic interactions in oligopeptides
Secondary structure conformations and long range electronic interactions in oligopeptides
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DOI：
10.1021/jp963771r
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发表时间：
1997-04-10
影响因子：
3.3
通讯作者：
Beratan, DN
中科院分区：
文献类型：
--
作者：
Wolfgang, J;Risser, SM;Beratan, DN
结合量子力学耦合计算和分子动力学模拟，研究了多肽二级结构的适度几何波动对寡肽中远程电子相互作用的作用。通过分子动力学模拟获得寡肽的典型相关构象，并在半经验量子理论水平上进行自一致Hartree-Fock计算以提取其远程电子传播。初始的a-螺旋寡肽在大的隧穿能量范围内表现出以空穴为主导的偶联，而初始的扩展构象寡肽在空穴和电子机制中的贡献几乎相等。适度的几何波动导致远程电子相互作用特性的变化。计算强调了在单一几何计算的基础上，从肽模型系统的电子耦合的电子结构计算中得出结论的危险性。
Combined quantum mechanical coupling calculations and molecular dynamics simulations were performed to examine the role of modest geometrical fluctuations of peptide secondary structures on long range electronic interactions in oligopeptides. Molecular dynamics simulations were performed to obtain typical relevant conformations of oligopeptides, and self-consistent Hartree-Fock calculations at the semiempirical quantum theory level were performed to extract the long range electronic propagation. Initial a-helical oligopeptides show dominant hole-mediated coupling over a large tunneling energy range, while the initial extended conformation oligopeptides have more nearly equal contributions from both hole and electron mechanisms. Modest geometrical fluctuations lead to changes in the character of long range electronic interactions. The computations highlight the danger of drawing conclusions from electronic structure calculations of electronic coupling in peptide model systems on the basis of computations on single geometries.