1.Synthesis and characterization of peptides containing a cyclic Val adduct of diepoxybutane, a possible biomarker of human exposure to butadiene.
Jayaraj K1, Georgieva NI, Gold A, Sangaiah R, Koc H, Klapper DG, Ball LM, Reddy AP, Swenberg JA. Chem Res Toxicol. 2003 May;16(5):637-43.
1,3-Butadiene, a potential human carcinogen widely used in industry, is oxidized by cytochrome P450 to diepoxybutane (DEB), which is the most mutagenic of the known butadiene metabolites. Assessment of the toxicological significance of DEB formation in humans and animals requires identification of a biomarker uniquely associated with DEB for use in molecular dosimetry studies. We wished to develop a specific and sensitive assay for one such suitable marker, the cyclic adduct 2-(3,4-dihydroxypyrrolidin-1-yl)-3-methylbutyramide (pyr-V), which is formed from addition of DEB to the terminal Val of the alpha- and beta-chains of hemoglobin. We needed to prepare a pure, rigorously characterized DEB-modified N-terminal oligopeptide for raising antibodies both to use in an immunoaffinity purification step and to standardize the assay. In addition, we needed a pure isotopomer to serve as an internal standard for quantitation by LC-MS. Direct modification of the globin sequences by reaction with DEB in vitro proved to be unproductive.
