[Separation and identification of the surface and secreted proteins in Toxoplasma gondii by biotin labeling and proteomics methods].

Objective: To separate and identify the surface proteins and secreted proteins of Toxoplasma gondii tachyzoites of RH strain.

Methods: T. gondii tachyzoites 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.