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Formation of globin mono‐adducts and cross‐links in erythrocytes after exposure to S‐(1,2‐dichlorovinyl)‐L‐cysteine sulfoxide
Author(s) -
Barshteyn Nella,
Elfarra Adnan
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.a813-c
Subject(s) - adduct , cysteine , chemistry , globin , hemoglobin , metabolite , stereochemistry , lysine , in vivo , in vitro , biochemistry , amino acid , organic chemistry , enzyme , biology , microbiology and biotechnology
Previously, our laboratory has shown that S‐(1,2‐dichlorovinyl)‐L‐cysteine sulfoxide (DCVCS), an FMO3‐dependent Michael acceptor produced from the trichloroethylene metabolite S‐(1,2‐dichlorovinyl)‐L‐cysteine (DCVC), is a more potent nephrotoxicant than DCVC. In the present study, we characterized reactions of DCVCS with nucleophilic amino acids and hemoglobin (Hb) in vitro . DCVCS incubations with N‐acetyl‐L‐cysteine (NAC) at pH 7.4, 37°C resulted in formation of three mono‐adducts and one di‐adduct characterized by MS and NMR, whereas DCVCS was not reactive with N‐acetyl‐L‐lysine or L‐valinamide. Because the NAC di‐adduct suggested DCVCS can form cross‐links with cysteine residues in proteins, we investigated globin cross‐link formation after Sprague‐Dawley rat erythrocytes were incubated for 2 h with 1–500 μM DCVCS at pH 7.4, 37°C. Globin dimers were detectable by 1D SDS‐PAGE/silver staining and by ESI/MS at all DCVCS concentrations. ESI/MS analysis of globin samples also revealed adduction of 1 and 2 DCVCS moieties on the β3 chain and 3 DCVCS moieties on the α2 chain. Thus, formation of protein mono‐adducts and cross‐links by DCVCS may play significant roles in DCVCS‐induced nephrotoxicity. Detection of the Hb mono‐adducts and cross‐links at such low DCVCS concentrations will help develop biomarker assays for DCVCS formation in vivo . (Supported by NIH Grant DK44295)