Proteomic analysis and assessment of heavy metals in hepatopancreas of mud crabs from Setiu and Kuala Sepetang

Abstract

Mud crabs are commonly found in Southeast Asia and are in high demand for its nutrients. However, studies reported that estuary areas are easily contaminated with pollutants due to the anthropogenic activities. Hepatopancreas is one of important tissues that involve in food digestions and detoxifications. Glutathione (GSH) and glutathione-S-transferase (GST) play roles in metabolisms of detoxification of xenobiotics. Therefore, this study focuses on the analysis of trace metals in hepatopancreas of mud crabs from Kuala Sepetang (highly contaminated area) and Setiu Wetlands (low contaminated area) and their protein response. Trace metals in hepatopancreas were analyzed by using Inductive Couple Plasma–Mass Spectrometer (ICP-MS). Proteins of hepatopancreas were extracted and GSH activity was measured. Next, protein expressions were observed in 1D electrophoresis and Western blotting. Our results shows that the concentrations of trace metals in hepatopancreas were highly significant in Kuala Sepetang compared with Setiu Wetlands. However, there is no significant difference in GSH activity in both locations. From 1D electrophoresis, the intensity of the protein band at ~60-75 kDa were dense in Kuala Sepetang compared with Setiu with values 15620.23±7829.83 and 3687.83±2933.69 respectively. Based on Western blot result, this protein band was related to GST as the response towards the level of trace metals abundance in the area. This proved that mud crabs in Sepetang location were stressed in polluted areas.