Trypanosoma simiae and Trypanosoma congolense: surface glycoconjugates of procyclic forms-the same coats on different hangers?
Organic solvent extraction, reverse-phase high performance liquid chromatography and enzyme-linked immunosorbent assay with surface binding monoclonal antibodies were used to isolate membrane molecules of procyclic culture forms of Trypanosoma simiae and Trypanosoma congolense. Gel electrophoresis of the purified molecules revealed two predominant molecular species from each parasite that were broadly similar yet showed different apparent molecular masses and staining characteristics. The molecules were shown to be glycosylphosphatidylinositol-lipid anchored glycoconjugates, rich in carbohydrates. Each moiety displayed surface-disposed carbohydrate epitopes that were recognized on the surface of both species of trypanosomes by monoclonal antibodies specific for procyclic parasites of the subgenus Nannomonas. The epitopes were previously shown to be displayed on the glutamic acid-alanine rich protein of T. congolense yet neither this protein, nor its encoding gene is present in T. simiae. The results indicate that although T. congolense and T. simiae share common carbohydrate surface epitopes, these are displayed on biochemically different molecules. We speculate that the surface disposed carbohydrate structures are involved in parasite-tsetse interactions since these species have the same developmental cycles in the insect vector.
Department of Biochemistry and Microbiology, Petch Building, University of Victoria, P.O. Box 3055, BC, Canada V8W 3P6. mookherjee@sask.usask.ca
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D000818:Animals; D015139:Blotting, Southern; D002462:Cell Membrane / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D019084:Fluorescent Antibody Technique, Indirect; D006001:Glycoconjugates / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D015800:Protozoan Proteins / Q000235:genetics; D014345:Trypanosoma / Q000737:chemistry* / Q000235:genetics; D014348:Trypanosoma congolense / Q000737:chemistry* / Q000235:genetics
C406724:GARP protein, Trypanosoma; D006001:Glycoconjugates; D015800:Protozoan Proteins