Abstract
Epidemiological and toxicological studies often require the analysis of large numbers of samples for biological markers of exposure. The goal of this work was to develop a class-selective ELISA to detect groups of structurally closely related mercapturic acids with small nonpolar S-substituents. An assay was developed with strong recognition for mercapturates including S-benzylmercapturic acid (IC50 = 0.018 μmol/L), S-n-hexylmercapturic acid (IC50 = 0.021 μmol/L), S-phenylmercapturic acid (IC50 = 0.024 μmol/L), and S-cyclohexylmethylmercapturic acid (IC50 = 0.042 μmol/L). The same assay also showed weaker recognition for S-(1-hydroxynaphthal-2-yl)mercapturic acid and S-allylmercapturic acid (IC50 = 1.1 and 1.7 μmol/L, respectively). Subtle modifications to the hapten linker structure of the coating antigen proved to have a strong impact on the selectivity and the specificity of the assay. A slightly modified assay showed high recognition for S-benzylmercapturic acid (IC50 = 0.018 μmol/L) and weaker recognition for seven other mercapturic acids (IC50 = 0.021-10 μmol/L). Strong positive assay responses were detected in 12 urine samples obtained from persons with no known occupational exposure to exogenous electrophilic xenobiotics. Solid phase extraction and cross-reactivity indicated that the presumptive immunoreactive materials were similar in size and polarity to S-benzylmercapturic acid. The assay was more selective to mercapturic acids than the spectrophotometric thioether assay.
Original language | English (US) |
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Pages (from-to) | 5913-5923 |
Number of pages | 11 |
Journal | Journal of Agricultural and Food Chemistry |
Volume | 48 |
Issue number | 12 |
DOIs | |
State | Published - 2000 |
Keywords
- Biological monitoring
- ELISA
- Mercapturic acid
- Urine
ASJC Scopus subject areas
- Agricultural and Biological Sciences (miscellaneous)
- Food Science
- Chemistry (miscellaneous)