Metalation of a rice type 1 metallothionein isoform (OsMTI-1b).
Protein Expr Purif
; 175: 105719, 2020 11.
Article
en En
| MEDLINE
| ID: mdl-32750405
ABSTRACT
The simultaneously functions of Metallothioneins (MTs) are relied on their metalation mechanisms that can be divided into non-cooperative, weakly cooperative and strongly cooperative mechanisms. In this study, we recombinantly synthesized OsMTI-1b, N- and C-terminal Cys-rich regions as glutathione-S-transferase (GST)-fusion proteins in E. coli. In comparison with control strains (The E. coli cells containing pET41a without gene), transgenic E. coli cells showed more tolerance against Cd2+ and Zn2+. The recombinant GST-proteins were purified using affinity chromatography. According to in vitro assays, the recombinant proteins showed a higher binding ability to Cd2+ and Zn2+. However, the affinity of apo-proteins to Cu2+ ions were very low. The coordination of Cd2+ ions in OsMTI-1b demonstrates a strongly cooperative mechanism with a priority for the C-terminal Cys-rich region that indicates the detoxifying of heavy metals as main role of P1 subfamily of MTs. While the metalation with Zn2+ conformed to a weakly cooperative mechanism with a specificity to N-terminal Cys-rich region. It implies the specific function of OsMTI-1b is involved in zinc homeostasis. Nevertheless, a non-cooperative metalation mechanism was perceived for Cu2+ that suggests the fully metalation does not occur and OsMTI-1b cannot play a significant role in dealing with Cu2+ ions.
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Texto completo:
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Banco de datos:
MEDLINE
Asunto principal:
Proteínas de Plantas
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Oryza
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Zinc
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Proteínas Recombinantes de Fusión
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Cadmio
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Cobre
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Metalotioneína
Idioma:
En
Año:
2020
Tipo del documento:
Article