title: Fe binding properties of two soybean (Glycine max L.) LEA4 proteins associated with antioxidant activity.
abstract: 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.
authors.affiliation: Institute of Genetics and Cytology, School of Life Science, Northeast Normal University, Changchun, PR China.
authors.forename: Guobao
authors.initials: G
authors.lastname: Liu
authors.forename: Hong
authors.initials: H
authors.lastname: Xu
authors.forename: Liao
authors.initials: L
authors.lastname: Zhang
authors.forename: Yizhi
authors.initials: Y
authors.lastname: Zheng
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D002151:Calorimetry; D002845:Chromatography / Q000379:methods; D002942:Circular Dichroism / Q000379:methods; D003855:Deoxyribose / Q000378:metabolism; D005453:Fluorescence; D017665:Hydroxyl Radical / Q000378:metabolism; D033862:Iron-Binding Proteins / Q000378:metabolism*; D019216:Metals, Heavy / Q000378:metabolism*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000378:metabolism*; D011993:Recombinant Fusion Proteins; D017422:Sequence Analysis, DNA; D012995:Solubility; D013025:Glycine max / Q000378:metabolism*; D013312:Stress, Physiological; D013816:Thermodynamics
chemical_list: D000975:Antioxidants; D033862:Iron-Binding Proteins; D019216:Metals, Heavy; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; C066246:late embryogenesis abundant protein, plant; D017665:Hydroxyl Radical; D003855:Deoxyribose