Interactions of Thellungiella salsuginea dehydrins TsDHN-1 and TsDHN-2 with membranes at cold and ambient temperatures-surface morphology and single-molecule force measurements show phase separation, and reveal tertiary and quaternary associations.
Interactions of Thellungiella salsuginea dehydrins TsDHN-1 and TsDHN-2 with membranes at cold and ambient temperatures-surface morphology and single-molecule force measurements show phase separation, and reveal tertiary and quaternary associations.
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DOI：
10.1016/j.bbamem.2012.11.031
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发表时间：
2013-03
期刊：
影响因子：
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通讯作者：
Luna N Rahman;Fraser McKay;M. Giuliani;A. Quirk;B. Moffatt;G. Harauz;J. Dutcher
中科院分区：
文献类型：
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作者：
Luna N Rahman;Fraser McKay;M. Giuliani;A. Quirk;B. Moffatt;G. Harauz;J. Dutcher
脱水蛋白（第2组胚胎发生晚期丰富蛋白）是在经历极端环境条件如干旱或低温的植物中表达的内在无序蛋白。它们的作用包括稳定细胞蛋白质和膜，以及螯合金属离子。在这里，我们调查的膜的相互作用的酸性β TsDHN-1和碱性β TsDHN-2来自十字花科Thellungiella salsuggelae，在加拿大亚北极蓬勃发展。我们表明，使用压缩研究与朗缪尔-布洛杰特槽，这两个foenins可以稳定脂质单层的脂质组成模仿植物外线粒体膜的组成，这在以前已被证明诱导有序的二级结构（无序到有序的转换）的蛋白质。在压缩过程中单层的椭圆偏振显示，在4°C下引入TsDHN-1（酸性）和在室温下引入TsDHN-2（碱性）后，单层厚度增加。原子力显微镜支持的脂质双层显示温度依赖性的相变和域的形成诱导的蛋白质。这些结果支持了推测，在冷胁迫条件下，酸性甜菜碱蛋白与植物线粒体外膜相互作用并潜在地稳定植物线粒体外膜。单分子力谱的两种蛋白质拉从支持的脂质双层表明诱导形成的三级构象在这两种蛋白质，和潜在的二聚体协会TsDHN-2。
Dehydrins (group 2 late embryogenesis abundant proteins) are intrinsically-disordered proteins that are expressed in plants experiencing extreme environmental conditions such as drought or low temperature. Their roles include stabilizing cellular proteins and membranes, and sequestering metal ions. Here, we investigate the membrane interactions of the acidic dehydrin TsDHN-1 and the basic dehydrin TsDHN-2 derived from the crucifer Thellungiella salsuginea that thrives in the Canadian sub-Arctic. We show using compression studies with a Langmuir–Blodgett trough that both dehydrins can stabilize lipid monolayers with a lipid composition mimicking the composition of the plant outer mitochondrial membrane, which had previously been shown to induce ordered secondary structures (disorder-to-order transitions) in the proteins. Ellipsometry of the monolayers during compression showed an increase in monolayer thickness upon introducing TsDHN-1 (acidic) at 4°C and TsDHN-2 (basic) at room temperature. Atomic force microscopy of supported lipid bilayers showed temperature-dependent phase transitions and domain formation induced by the proteins. These results support the conjecture that acidic dehydrins interact with and potentially stabilize plant outer mitochondrial membranes in conditions of cold stress. Single-molecule force spectroscopy of both proteins pulled from supported lipid bilayers indicated the induced formation of tertiary conformations in both proteins, and potentially a dimeric association for TsDHN-2.