PROTEINS EXPRESSION IN Acanthamoeba castellanii AFTER EXPOSURE TO AMMONIUM CHLORIDE

Abstract

The aquatic environment is easily contaminated with ammonium from the release of biological wastes that contain ammonium into rivers and oceans by urban and agricultural run-off and this affects the life of aquatic organisms, including small, free-living naked amoebae such as Acanthamoeba spp. These amoebae are common in water and, being single-cell organisms, they can easily respond to any changes in the environment, such as ammonium contamination, by expressing specific proteins known as biomarkers which can be suggested as a new tool for rapid diagnosis and monitoring of environmental health hazard. In this study, Acanthamoeba castellanii was treated with different concentrations of ammonium chloride (NH4Cl) and the cytotoxicity of ammonium chloride on the amoeba and its IC 50 were examined and determined. The treated amoebae were also subjected to 2-D electrophoresis for protein profile analysis. The IC50 of NH4Cl against A. castellanii obtained in this study was 0.64 mg/mL. In the protein profile analysis, the total number of protein spots that were consistently observed in control Acanthamoeba were 93, and the number of these spots decreased as the concentration of NH4Cl used increased. Besides that, some newly-expressed protein spots were observed in treated Acanthamoeba. Degradation of certain proteins and synthesis of new proteins in treated Acanthamoeba observed in the present study may be indicative of cellular stress and these proteins can be used as biomarkers to access ammonium contamination in the aquatic environment for preventive measures.