Analysis of Structures and Epitopes of Surface Antigen Glycoproteins Expressed in Bradyzoites of Toxoplasma gondii

Biomed Res Int. 2013;2013:165342. doi: 10.1155/2013/165342. Epub 2013 Mar 21.

Analysis of Structures and Epitopes of Surface Antigen Glycoproteins Expressed in Bradyzoites of Toxoplasma gondii

Cong H, Zhang M, Zhang Q, Gong J, Cong H, Xin Q, He S.

Department of Human Parasitology, School of Medicine, Shandong University, No. 44 Wenhuaxi Road, Jinan, Shandong 250012, China.

Toxoplasma gondii is a protozoan parasite capable of infecting humans and animals. Surface antigen glycoproteins, SAG2C, -2D, -2X, and -2Y, are expressed on the surface of bradyzoites. These antigens have been shown to protect bradyzoites against immune responses during chronic infections. We studied structures of SAG2C, -2D, -2X, and -2Y proteins using bioinformatics methods. The protein sequence alignment was performed by T-Coffee method. Secondary structural and functional domains were predicted using software PSIPRED v3.0 and SMART software, and 3D models of proteins were constructed and compared using the I-TASSER server, VMD, and SWISS-spdbv. Our results showed that SAG2C, -2D, -2X, and -2Y are highly homologous proteins. They share the same conserved peptides and HLA-I restricted epitopes. The similarity in structure and domains indicated putative common functions that might stimulate similar immune response in hosts. The conserved peptides and HLA-restricted epitopes could provide important insights on vaccine study and the diagnosis of this disease.

PMID: 23586017 [PubMed - in process]