Abstract: Objective  To separate and identify the surface proteins and secreted proteins of Toxoplasma gondii tachyzoties of RH strain.  Methods  T. gondii tachyzoties were cultured in Vero cells, and purified by filtration and Percoll cell separation solution. The biotin-labeled tachyzoites were lysed, and the surface and secreted proteins were separated by NeutrAvidin agarose beads. After condensation and SDS-PAGE, the protein were collected, digested and identified by LC/MS-MS.  Results  A total of 785 T. gondii proteins were identified, 81 (10.3%) of which were originally annotated as the surface or secreted proteins. Among the highly-expressed (PSM>10) 65 proteins, 43 (66%) were originally annotated as surface or secreted proteins, while the others were predicted unknown proteins.  Conclusion  The surface and secreted proteins of T. gondii are separated by biotin labeling and avidin chromatography, among which some potential new surface or secreted proteins of T. gondii are identified.

Key words: Toxoplasma gondii, Surface protein, Secreted protein, Biotin labeling, Liquid chromatography-mass spectrometry/mass spectrometry(LC?鄄MS/MS)