Protein targets of 1,4-benzoquinone and 1,4-naphthoquinone in human bronchial epithelial cells.

Many aspects of the toxicity of xenobiotic compounds have been attributed to the consequences of covalent modification of specific proteins, but the nature and specificity of protein targets for classes of electrophilic toxins remain largely uncharacterized. For inhaled toxicants, the point of exposure or absorption lies with epithelial cells lining the pulmonary tree. In this study, abundant proteins in human bronchial epithelial cells that are arylated in vitro by two quinonoid compounds, 1,4-benzoquinone (BQ) and 1,4-naphthoquinone (NQ) have been detected using (14)C-labeled quinones and two-dimensional gel electrophoresis.