COMPLEX MIXTURE ANALYSIS USING PROTEIN EXPRESSION AS A QUALITATIVE AND QUANTITATIVE TOOL

Some proteins in organisms exposed to chemicals in stressful amounts o r toxic concentrations show increased expression; others show decrease d expression. These inducible and repressible proteins together potent ially provide qualitative and quantitative diagnoses of components in complex mixtures of chemicals. We examined sets of proteins synthesize d by Daphnia magna after exposure to mixtures of a cationic polyamide epichlorhydrin adduct (Kymene) and a combined assortment of water-extr actable substances from chemi-thermal-mechanical pulp (CTMP) in lab wa ter. Proteins were identified, after extracting from Daphnia magna, by gel filtration and silver staining, or by radiolabeling and then gel separation. Patterns of proteins induced by Kymene(R) and by CTMP extr acts were distinguishable in lab water, but there was interaction betw een them. The method of identifying and quantifying Kymene, however, w as successful using lab simulations of mixtures. The method was tested using wastewater samples from a paper manufacturing plant. Kymene cou ld be detected against variable levels and types of additional substan ces. But, again, there was interference, perhaps due to Kymene binding to other anionic polymers sometimes present in the samples. Interpret ations from analyses of protein expression were consistent with result s from sublethal Ceriodaphnia dubia assays.