Enrichment and biochemical characterization of Toxoplasma gondii tachyzoite plasmalemma.
The protozoan parasite Toxoplasma gondii possesses a triple surface membrane called the pellicle. This is made of an outer plasmalemma and an inner membrane complex lying under the plasmalemma. Using a high salt glycerol treatment followed by sonication, we have obtained a partial dissociation of the pellicle. A plasmalemma-enriched fraction was isolated on 0.7 M sucrose. It was identified by immunodetection of the tachyzoite major surface antigens. Protein content, resolved by SDS-PAGE, revealed that the surface protein SAG1 is the major component of the plasmalemma. The plasmalemma fraction is made of small vesicles (20-100 nm) which possess a low density (1.085-1.090 g/cm3 in sucrose) contrasting with other eukaryotic plasma membranes (1.12-1.16 g/cm3).
Rabjeau
A
A
Laboratoire de Biochimie et Biologie Moléculaire, Faculté de Médecine, Angers, France.
Foussard
F
F
Mauras
G
G
Dubremetz
J F
JF
D000818:Animals; D000953:Antigens, Protozoan; D000954:Antigens, Surface / Q000032:analysis / Q000737:chemistry; D002462:Cell Membrane / Q000737:chemistry / Q000648:ultrastructure; D008970:Molecular Weight; D015800:Protozoan Proteins / Q000032:analysis* / Q000737:chemistry; D014122:Toxoplasma / Q000737:chemistry / Q000648:ultrastructure*
D000953:Antigens, Protozoan; D000954:Antigens, Surface; D015800:Protozoan Proteins; C047168:SAG1 antigen, Toxoplasma