Fe Binding Properties of Two Soybean (Glycine max L.) LEA4 Proteins Associated with Antioxidant Activity
Fe Binding Properties of Two Soybean (Glycine max L.) LEA4 Proteins Associated with Antioxidant Activity
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DOI：
10.1093/pcp/pcr052
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发表时间：
2011-06-01
影响因子：
4.9
通讯作者：
Zheng, Yizhi
中科院分区：
文献类型：
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作者：
Liu, Guobao;Xu, Hong;Zheng, Yizhi
晚期胚胎发生丰富(LEA)组4(LEA4)蛋白在植物耐水分胁迫中起着重要作用。尽管LEA4蛋白被认为可以稳定应激细胞中的大分子，但其保护功能和机制仍不清楚。本研究采用固定化金属离子亲和层析技术(IMAC)研究了两种大豆LEA4相关蛋白GmPM1和GmPM9的金属结合特性。金属离子Fe(3+)、Ni(2+)、Cu(2+)和Zn(2+)与这两种蛋白结合，而Ca(2+)、Mg(2+)和Mn(2+)则不结合。等温滴定量热法(ITC)结果表明，GmPM1与Fe(3+)的结合亲和力强于GmPM9。GmPM1和GmPM9对Fe(3+)/H(2O)O(2)体系产生的羟基自由基均有清除作用，但GmPM1和GmPM9的清除活性明显高于GmPM9。这些结果表明，GmPM1和GmPM9是金属结合蛋白，可能在减轻非生物胁迫诱导的植物氧化损伤中发挥作用。
Late embryogenesis abundant (LEA) group 4 (LEA4) proteins play an important role in the water stress tolerance of plants. Although they have been hypothesized to stabilize macromolecules in stressed cells, the protective functions and mechanisms of LEA4 proteins are still not clear. In this study, the metal binding properties of two related soybean LEA4 proteins, GmPM1 and GmPM9, were tested using immobilized metal ion affinity chromatography (IMAC). The metal ions Fe(3+), Ni(2+), Cu(2+) and Zn(2+) were observed to bind these two proteins, while Ca(2+), Mg(2+) or Mn(2+) did not. Results from isothermal titration calorimetry (ITC) indicated that the binding affinity of GmPM1 for Fe(3+) was stronger than that of GmPM9. Hydroxyl radicals generated by the Fe(3+)/H(2)O(2) system were scavenged by both GmPM1 and GmPM9 in the absence or the presence of high ionic conditions (100 mM NaCl), although the scavenging activity of GmPM1 was significantly greater than that of GmPM9. These results suggest that GmPM1 and GmPM9 are metal-binding proteins which may function in reducing oxidative damage induced by abiotic stress in plants.