title: Development of a class-selective enzyme-linked immunosorbent assay for mercapturic acids in human urine.
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 micromol/L), S-n-hexylmercapturic acid (IC50 = 0.021 micromol/L), S-phenylmercapturic acid (IC50 = 0.024 micromol/L), and S-cyclohexylmethylmercapturic acid (IC50 = 0.042 micromol/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 micromol/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 micromol/L) and weaker recognition for seven other mercapturic acids (IC50 = 0.021-10 micromol/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.
authors: Department of Entomology and the UCDMC Cancer Center, University of California, Davis, California 95616, USA.
authors: C
authors: C
authors: Lohse
authors: L L
authors: LL
authors: Jaeger
authors: N
authors: N
authors: Staimer
authors: J R
authors: JR
authors: Sanborn
authors: A D
authors: AD
authors: Jones
authors: J
authors: J
authors: Langó
authors: S J
authors: SJ
authors: Gee
authors: B D
authors: BD
authors: Hammock
mesh_terms: D000111:Acetylcysteine / Q000652:urine*; D004781:Environmental Exposure / Q000032:analysis*; D004784:Environmental Monitoring; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D010573:Pesticide Residues; D012680:Sensitivity and Specificity
chemical_list: D010573:Pesticide Residues; D000111:Acetylcysteine