Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8332097 | International Journal of Biological Macromolecules | 2015 | 6 Pages |
Abstract
Metallothioneins (MTs) are low-molecular weight proteins with high Cys content and a high affinity for metals. Plant MTs are classified into four types based on the arrangement of Cys in their amino acid sequences. In the present study, the gene encoding OsMTI-3a, a type 3 MT found in rice, was cloned into pET41a vector. The resulting construct was transformed into the Escherichia coli strain Rosetta (DE3). Following the induction with isopropyl β-d-1-thiogalactopyranoside, the OsMTI-3a was expressed as glutathione-S-transferase (GST)-tagged fusion protein. In comparison to control strain, the cells expressing GST-OsMTI-3a accumulated more Cd2+, Ni2+ and Zn2+ when they were grown in the medium containing CdCl2, NiCl2 or ZnSO4. The recombinant GST-OsMTI-3a was purified using affinity chromatography. The UV absorption spectra recorded after the reconstitution of the apo-protein with different metals confirmed that GST-OsMTI-3a was able to form complexes with Cd2+, Ni2+, and Zn2+. The reaction of the protein-metal complexes with 5-5-dithiobis (2-nitrobenzoic) revealed that the order of affinity of GST-OsMTI-3a toward different metals was Ni2+ â¥Â Cd2+ > Zn2+ > Cu2+.
Keywords
Related Topics
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Biochemistry, Genetics and Molecular Biology
Biochemistry
Authors
Azar Shahpiri, Iman Soleimanifard, Mohammad Ali Asadollahi,