Concentration Dependent Effects of Ca~(2+) and Mg~(2+) on the Phosphatidylethanolamine-Phosphatidylglycerol Bilayer
文献类型：期刊论文
| 作者 | Zhang Tao3; Qiu Yunguang2; Luo Qichao2; Cheng Xi2; Zhao Lifen2; Yan Xin1; Peng Bo2; Jiang Hualiang3 ; Yang Huaiyu2
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| 刊名 | Acta Physica-Chimica Sinica
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| 出版日期 | 2019 |
| 卷号 | 35期号:8页码:840 |
| 关键词 | 二价阳离子 磷脂双分子层 动态光散射 Zeta电势 分子动力学模拟 相互作用 |
| ISSN号 | 1000-6818 |
| 英文摘要 | Ca~(2+) and Mg~(2+) ions are the main divalent cations in living cells and play vital roles in the structure and function of biological membranes. To date, the differences in the effects of these two ions on the Escherichia coli(E. coli) inner membrane at various concentrations remain unknown. Here, the effects of Ca~(2+) and Mg~(2+) ions on a mixed lipid bilayer composed of 1- palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine(POPE) and 1- palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol(POPG) in a 3: 1 ratio(mol/mol), which mimics the E. coli inner membrane, were quantitatively differentiated at different concentrations by dynamic light scattering(DLS), zeta potential measurements and all-atom molecular dynamics(AA-MD) simulations. The DLS results demonstrated that the POPE/POPG liposomes were homogeneous and monodisperse in solutions with Ca~(2+) or Mg~(2+) ion concentrations of 0 and 1 mmol·L~(–1). As the Ca~(2+) or Mg~(2+) ion concentration was increased to 5–100 mmol·L~(–1), lipid aggregation or the fusion of unilamellar liposomes occurred in the ion solutions. The zeta potential measurements showed that both the Ca~(2+) and Mg~(2+) ions had overcharging effects on the negatively charged POPE/POPG liposomes. The AA-MD simulation results indicated that the Ca~(2+) ions irreversibly adsorbed on the membranes when the simulation time was longer than 100 ns, while the Mg~(2+) ions were observed to dynamically adsorb on and desorb from the membranes at various concentrations. These results are consistent with the DLS and zeta potential experiments. The average numbers of Ca~(2+) and Mg~(2+) ions in the first coordination shell of the oxygen atoms of the phosphate, carbonyl and hydroxyl groups of POPE and POPG(i.e., the first coordination numbers) in the pure membrane and membranes containing 5 and 100 mmol·L~(–1) ions were calculated from the radial distribution functions. The results indicated that the primary binding site of these two ions on POPE and POPG at the concentrations studied was the negatively charged phosphate group. Thus, these results might explain the overcharging effects of both the Ca~(2+) and Mg~(2+) ions on the POPE/POPG liposomes. Moreover, as the Ca~(2+) concentration increased, the area per lipid of the lipid bilayers decreased, and the membrane thickness increased, while the Mg~(2+) ions had negligible effects on these membrane parameters. In addition, these ions had different effects on the orientation of the lipid head groups. These simulation results may be used to provide the possible explanations for the differences between Ca~(2+) and Mg~(2+) ions in DLS and zeta potential measurements at the atomic level. The experimental results and MD simulations provide insight into various biological processes regulated by divalent cations, such as membrane fusion. |
| 语种 | 英语 |
| 源URL | [http://119.78.100.183/handle/2S10ELR8/293192]  |
| 专题 | 新药研究国家重点实验室 |
| 作者单位 | 1.School of Life Science and Technology,ShanghaiTech University 2.中国科学院上海药物研究所 3.中华科技大学 |
| 推荐引用方式 GB/T 7714 | Zhang Tao,Qiu Yunguang,Luo Qichao,et al. Concentration Dependent Effects of Ca~(2+) and Mg~(2+) on the Phosphatidylethanolamine-Phosphatidylglycerol Bilayer[J]. Acta Physica-Chimica Sinica,2019,35(8):840. |
| APA | Zhang Tao.,Qiu Yunguang.,Luo Qichao.,Cheng Xi.,Zhao Lifen.,...&Yang Huaiyu.(2019).Concentration Dependent Effects of Ca~(2+) and Mg~(2+) on the Phosphatidylethanolamine-Phosphatidylglycerol Bilayer.Acta Physica-Chimica Sinica,35(8),840. |
| MLA | Zhang Tao,et al."Concentration Dependent Effects of Ca~(2+) and Mg~(2+) on the Phosphatidylethanolamine-Phosphatidylglycerol Bilayer".Acta Physica-Chimica Sinica 35.8(2019):840. |
入库方式： OAI收割
来源：上海药物研究所
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