Study On Toxic Effects And Comparative Proteomic Analysis Of Differentially Expressed Proteins In The Earthworm Eisenia Fetida During Dimethylphthalate Stress

Paper contact and soil contact tests were performed to study on toxic effects of dimethylphthalate to the earthworm Eisenia fetida, then differentially expressed proteins in the earthworm Eisenia fetida during dimethylphthalate stress analysed by2-DE and identified by MALDI-TOF/TOF-MS maybe useful as biomarker profiles to investigate DMP contamination levels in soils. The results are showed as follow:1. Paper contact and soil contact tests were performed to study on toxic effects of dimethylphthalate to the earthworm Eisenia fetida.The results showed that the value LC50of DMP was140.305μg/cm2after24hours exposure,130.662μg/cm2after48hours exposure by paper contact; the value LC50of DMP was2124.066mg/kg after7d exposure,1356.745mg/kg after14d exposure, when the earthworm Eisenia fetida lived in a DMP-polluted600mg/kg environment21d, the weight inhibition was21.93%indicated that earthworm reduced metabolism to adapt to polluted environment.Extracts of whole earthworms, living in a DMP-polluted environment（200mg/kg,600mg/kg）, collected at days7,14, and21were analyzed by2-DE and quantitative image analysis. In total,140proteins demonstrated significant regulation in at least at one time point. Compared with control samples, part of differential protein spots were identified by peptide mass fingerprint based on MALDI-TOF-MS. Five differential expressed proteins were identified, including BRAFLCRAFT₅8397, Alpha tubulin, ATP synthase beta subunit, Beta tubulin, FAEPRAM21203570. The variable levels and trends in these spots on the gel may be useful as biomarker profiles to investigate DMP contamination levels in soils.2. The DMP concentrations in mouse liver homogenate were determined by the High performance liquid chromatography（HPLC）, the results show that Ln（C）=-0.20251t+7.32206, R2=0.9673. The elimination half-life of DMP in mouse liver was3.42min. The pseudo-first-order kinetic model is in good agreement with the experimental date.