Metalation of a rice type 1 metallothionein isoform (OsMTI-1b).
Protein Expr Purif
; 175: 105719, 2020 11.
Article
in 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.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Plant Proteins
/
Oryza
/
Zinc
/
Recombinant Fusion Proteins
/
Cadmium
/
Copper
/
Metallothionein
Language:
En
Journal:
Protein Expr Purif
Journal subject:
BIOLOGIA MOLECULAR
Year:
2020
Document type:
Article