Demethylation of Methylmercury in Bird, Fish, and Earthworm.
Environ Sci Technol
; 55(3): 1527-1534, 2021 02 02.
Article
en En
| MEDLINE
| ID: mdl-33476127
ABSTRACT
Toxicity of methylmercury (MeHg) to wildlife and humans results from its binding to cysteine residues of proteins, forming MeHg-cysteinate (MeHgCys) complexes that hinder biological functions. MeHgCys complexes can be detoxified in vivo, yet how this occurs is unknown. We report that MeHgCys complexes are transformed into selenocysteinate [Hg(Sec)4] complexes in multiple animals from two phyla (a waterbird, freshwater fish, and earthworms) sampled in different geographical areas and contaminated by different Hg sources. In addition, high energy-resolution X-ray absorption spectroscopy (HR-XANES) and chromatography-inductively coupled plasma mass spectrometry of the waterbird liver support the binding of Hg(Sec)4 to selenoprotein P and biomineralization of Hg(Sec)4 to chemically inert nanoparticulate mercury selenide (HgSe). The results provide a foundation for understanding mercury detoxification in higher organisms and suggest that the identified MeHgCys to Hg(Sec)4 demethylation pathway is common in nature.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Oligoquetos
/
Mercurio
/
Compuestos de Metilmercurio
Límite:
Animals
/
Humans
Idioma:
En
Año:
2021
Tipo del documento:
Article