Molecular mechanism study on the interactions of cadmium (II) ions with Arabidopsis thaliana glutathione transferase Phi8

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Vol. 216; pp. 411 - 417
• Main Authors: Hou, Xiaomin, Tan, Lingling, Tang, Si-Fu
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 05.06.2019
• Subjects: Arabidopsis - chemistry; Arabidopsis - metabolism; Arabidopsis Proteins - chemistry; Arabidopsis Proteins - metabolism; AtGSTF8; Binding Sites; Cadmium - metabolism; Cations, Divalent - metabolism; Glutathione Transferase - chemistry; Glutathione Transferase - metabolism; Molecular mechanism; Oxidative Stress; Protein Binding; Protein Structure, Secondary; Thermodynamics; AtGSTF8; Oxidative stress; Molecular mechanism
• ISSN: 1386-1425; 1873-3557
• DOI: 10.1016/j.saa.2019.03.048

Accumulation of cadmium ions may result in adverse effects on plant due to the oxidative stress via destructions of antioxidants and antioxidant enzymes. As the core component of the glutathione antioxidant system, glutathione S-transferases (GSTs) have been reported as biomarkers for evaluating the metal-induced oxidative damage to plants, but the potential toxicity and underlying toxic molecular mechanisms remain unknown. This article investigated the molecular interactions of cadmium ions with Arabidopsis thaliana glutathione S-transferase phi8 (AtGSTF8) by multi-spectroscopic techniques and enzyme activity measurements. The intrinsic fluorescence of AtGSTF8 was quenched statically upon the addition of cadmium ions accompanied with the complex formation and structural and conformational alterations from multiple spectroscopic measurements, resulting in deconstructed protein skeleton and microenvironmental alterations around the Tyr and Trp residues. A single binding site was predicted for AtGSTF8 towards cadmium ions and the van der Walls interactions and hydrogen bonds are the major driving forces of the interaction. In addition, the transferase activity changes of AtGSTF8 upon the addition of cadmium ions have been observed. The implementation of this work helps to clarify the mechanism of oxidative damage and antioxidant enzymes response induced by heavy metal accumulation in plant at molecular level. [Display omitted] •AtGSTF8 from Arabidopsis thaliana was expressed and purified for the first time.•The molecular interaction of cadmium ions with AtGSTF8 in vitro was investigated for the first time.•The secondary structure of AtGSTF8 was changed by cadmium ions.