title: Liberation and analysis of protein-bound arsenicals.
abstract: Protein-bound arsenicals were liberated from binding sites on liver cytosolic proteins by exposure to 0.1 M CuCl at pH 1. This method released greater than 90% of the arsenicals associated with biological matrices. Ultrafiltrates of CuCl-treated cytosols were subjected to thin-layer chromatography to speciate and quantify inorganic and methylated arsenicals. For rat liver cytosol in an in vitro methylation assay and for liver and kidney cytosols from arsenite-treated mice, most inorganic arsenic was protein bound. Appreciable fractions of the organoarsenical metabolites present in these cytosols were also protein bound. Therefore, CuCl treatment of cytosols releases protein-bound arsenicals, permitting more accurate estimates of the pattern and extent of arsenic methylation in vitro and in vivo.
authors.affiliation: Curriculum in Toxicology, University of North Carolina at Chapel Hill, 27514, USA.
authors.forename: M
authors.initials: M
authors.lastname: Styblo
authors.forename: M F
authors.initials: MF
authors.lastname: Hughes
authors.forename: D J
authors.initials: DJ
authors.lastname: Thomas
mesh_terms: D000818:Animals; D001151:Arsenic; D001152:Arsenicals / Q000032:analysis* / Q000378:metabolism*; D002855:Chromatography, Thin Layer; D003600:Cytosol / Q000737:chemistry; D007202:Indicators and Reagents; D007668:Kidney / Q000737:chemistry; D008099:Liver / Q000737:chemistry; D008745:Methylation; D051379:Mice; D011485:Protein Binding; D011868:Radioisotopes; D051381:Rats; D014462:Ultrafiltration
chemical_list: D001152:Arsenicals; D007202:Indicators and Reagents; D011868:Radioisotopes; D001151:Arsenic