分子动力学研究MeV质子辐照对生物分子二级结构的影响

Molecular dynamics study on secondary structure changes of peptide sample irradiated with MeV protons

利用分子动力学方法对MeV质子辐照多肽分子所引起的分子空间结构变化进行了研究,对比了不同质子能损和模拟条件下分子构象变化的差异。结果表明,在质子轰击下,分子的二级结构在其得到3—5eV能量后出现明显的变化,从α螺旋结构向β折叠逐渐转变,并且这种变化与质子能量的沉积方式有关。与温度效应的对照显示,质子辐照引起的变化与温度所引起的变化有明显的差异:质子辐照产生的分子构象更丰富多样,而温度所引起的变化则比较单一。

The molecular dynamics method was used to simulate the conformation changes of the secondary structure of peptide molecules induced by MeV proton irradiation. The simulation results indicate that the sample's secondary structure was changed from α-helix to β-sheet gradually when the sample got energy higher than 3-5 eV from the incident ion, and the energy transfer mode has significant effect on final secondary structure of the sample. Besides, the proton irradiation causes manifold final secondary structures compared with that caused by raising the sample temperature.