Journal
INORGANIC CHEMISTRY
Volume 55, Issue 4, Pages 1505-1515Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acs.inorgchem.5b02327
Keywords
-
Categories
Funding
- Indian Ministry for Science and Technology, Department of Biotechnology
- Advantage West Midlands
- European Regional Development Fund
Ask authors/readers for more resources
Molecules for remediating or recovering uranium from contaminated environmental resources are of high current interest, with protein-based ligands coming into focus recently. Metallothioneins either bind or redox-silence a range of heavy metals, conferring protection against metal stress in many organisms. Here, we report that the cyanobacterial metallothionein SmtA competes with carbonate for uranyl binding, leading to formation of heterometallic (UO2)(n)Zn(4)SmtA species, without thiol oxidation, zinc loss, or compromising secondary or tertiary structure of SmtA. In turn, only metalated and folded SmtA species were found to be capable of uranyl binding. H-1 NMR studies and molecular modeling identified Glu34/Asp38 and Glu12/C-terminus as likely adventitious, but surprisingly strong, bidentate binding sites. While it is unlikely that these interactions correspond to an evolved biological function of this metallothionein, their occurrence may offer new possibilities for designing novel multipurpose bacterial metallothioneins with dual ability to sequester both soft metal ions including Cu+, Zn2+, Cd2+, He2+, and Pb2+ and hard, high-oxidation state heavy metals such as U(VI). The concomitant protection from the chemical toxicity of uranium may be valuable for the development of bacterial strains for bioremediation.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available