Isolation and characterization of the Golgi complex of the protozoan Trypanosoma cruzi

In this study the Golgi complex of the epimastigote forms of Trypanosoma cr uzi were isolated and characterized. Using well-controlled sonication to ru pture the cells and centrifugation on a discontinuous sucrose density gradi ent, a highly enriched Golgi fraction was obtained. The Golgi fraction cont ained most of the beta -galactosyltransferase (beta -Gal transferase) and U DP-N-acetyl-glucosamine: polypeptide-alpha -N-acetyl-glucosaminyltransferas e (O-alpha -GlcNAc transferase) activities with minimal contamination of ot her organelles, as observed by enzymatic assays and electron microscopy ana lysis. To characterize the Golgi from T. cruzi cells further, it was incuba ted with a monoclonal antibody against a 58 kDa protein involved in the ass ociation of the Golgi complex with microtubules in mammalian cells. Immunof luorescence microscopy showed that the 58 kDa protein is localized in the T . cruzi Golgi region, a result confirmed by high resolution scanning electr on microscopy immunocytochemistry. Thus, our results show, for the first ti me, that the beta -Gal transferase, the alpha -GlcNAc transferase and the 5 8 kDa protein are present in the Golgi complex of T. cruzi and are novel bi ochemical markers which can be used in the characterization of this organel le in T. cruzi.