Abstract: 　Objective To provide a theoretical basis for the study of vaccines against Schistosoma japonicum , the receptor for human LDL in the tegument of adult Schistosoma japonicum was investigated. Methods Proteins existed in adult Schistosoma japonicum membrane were extracted by Triton X-100 and purified through reverse-phase high performance liquid chromatography (HPLC),and the main protein peaks were then collected separately. 125 I-LDL of human plasma as the ligand, through the radioautography and radioligand binding assay, the protein which can bind human serum 125 I-LDL specifically was identified. The molecular weight and IEF were detected by SDS-PAGE. Results According to the radioautography and radioligand binding assay, a protein with retention time of 10.5 min was proved to be able to bind human serum 125 I-LDL specifically. SDS-PAGE revealed that the molecular weight of the purified protein is 60-65 kDa, and its IEF is 6.7. Conclusion LDL binding protein may exist on the surface of both male and female adult Schistosoma japonicum with the function of obtaining cholesterol from host circulating system.

Key words: Schistosoma japonicum, LDL, high performance liquid chromatography (HPLC), radioligand binding assay