Su Jingjie, Sun Tingting, Wang Yan, Shen Yu
Department of Applied Physics, Zhejiang University of Science and Technology, No. 318 Liuhe Road, Hangzhou 310018, China.
Polymers (Basel). 2022 Jul 3;14(13):2722. doi: 10.3390/polym14132722.
Molecular dynamics (MD) simulation was used to study the influence of electric field on Glucagon-like Peptide-2 (GLP-2). Different electric field strengths (0 V/nm ≤ E ≤ 1 V/nm) were mainly carried out on GLP-2. The structural changes in GLP-2 were analyzed by the Root Mean Square Deviation (RMSD), Root Mean Square Fluctuation (RMSF), Radius of Gyration (Rg), Solvent Accessible Surface Area (SASA), Secondary Structure and the number of hydrogen bonds. The stable α—helix structure of GLP-2 was unwound and transformed into an unstable Turn and Coil structure since the stability of the GLP-2 protein structure was reduced under the electric field. Our results show that the degree of unwinding of the GLP-2 structure was not linearly related to the electric field intensity. E = 0.5 V/nm was a special point where the degree of unwinding of the GLP-2 structure reached the maximum at this electric field strength. Under a weak electric field, E < 0.5 V/nm, the secondary structure of GLP-2 becomes loose, and the entropy of the chain increases. When E reaches a certain value (E > 0.5 V/nm), the electric force of the charged residues reaches equilibrium, along the z-direction. Considering the confinement of moving along another direction, the residue is less free. Thus, entropy decreases and enthalpy increases, which enhance the interaction of adjacent residues. It is of benefit to recover hydrogen bonds in the middle region of the protein. These investigations, about the effect of an electric field on the structure of GLP-2, can provide some theoretical basis for the biological function of GLP-2 in vivo.
采用分子动力学（MD）模拟研究电场对胰高血糖素样肽-2（GLP-2）的影响。主要对GLP-2施加不同的电场强度（0 V/nm≤E≤1 V/nm）。通过均方根偏差（RMSD）、均方根波动（RMSF）、回转半径（Rg）、溶剂可及表面积（SASA）、二级结构和氢键数量分析GLP-2的结构变化。由于在电场作用下GLP-2蛋白质结构的稳定性降低，其稳定的α-螺旋结构展开并转变为不稳定的转角和卷曲结构。我们的结果表明，GLP-2结构的展开程度与电场强度并非线性相关。E = 0.5 V/nm是一个特殊点，在此电场强度下GLP-2结构的展开程度达到最大值。在弱电场（E < 0.5 V/nm）下，GLP-2的二级结构变得松散，链的熵增加。当E达到一定值（E > 0.5 V/nm）时，带电残基的电力沿z方向达到平衡。考虑到沿另一个方向移动的限制，残基的自由度降低。因此，熵减小，焓增加，这增强了相邻残基之间的相互作用。这有利于蛋白质中间区域氢键的恢复。这些关于电场对GLP-2结构影响的研究可为GLP-2在体内的生物学功能提供一些理论依据。
