Coated vesicles from the protozoan parasite Trypanosoma brucei: purification and characterization.
A procedure was developed to purify a coated vesicle fraction from the protozoan parasite Trypanosoma brucei. Electron microscopy revealed a difference between T. brucei coated vesicles and clathrin-coated vesicles from other eukaryotes: trypanosome vesicles were larger (100 to 150 nm in diameter) and contained an inner coat of electron-dense material in addition to the external coat. Evidence suggests that the internal coat is the parasite's variant surface glycoprotein (VSG) coat. The SDS-PAGE analysis shows the major protein of T. brucei coated vesicles has a molecular mass of 61 kD, similar to VSG; this protein was recognized in an immunoblot by anti-VSG serum. Trypanosome coated vesicles also contain a protein which comigrates with the major protein (clathrin) of coated vesicles purified from rat brains. However, this protein is a minor component and it is not serologically cross-reactive with mammalian clathrin. Immunoblot analysis demonstrated that the parasite vesicles contained host IgG, IgM, and serum albumin.
Shapiro
S Z
SZ
International Laboratory for Research on Animal Diseases (ILRAD), Nairobi, Kenya.
Webster
P
P
D000818:Animals; D015153:Blotting, Western; D002966:Clathrin / Q000032:analysis; D003034:Coated Pits, Cell-Membrane / Q000032:analysis / Q000648:ultrastructure*; D004591:Electrophoresis, Polyacrylamide Gel; D011992:Endosomes / Q000648:ultrastructure*; D051381:Rats; D011919:Rats, Inbred Strains; D014346:Trypanosoma brucei brucei / Q000032:analysis / Q000648:ultrastructure*
D002966:Clathrin