IMMUNOLOGICAL CHARACTERIZATION OF CYTOSKELETAL PROTEINS ASSOCIATED WITH THE BASAL BODY, AXONEME AND FLAGELLUM ATTACHMENT ZONE OF TRYPANOSOMA-BRUCEI

The monoclonal antibody BS7, raised to bovine sperm flagellum cytoskel etal antigens in a previous study, is here reported to detect flagellu m-associated structures in Trypanosoma brucei and Crithidia fasciculat a. Immunoblotting showed that BS7 cross-reacts with several cytoskelet al T. brucei proteins but phosphatase treatment did not diminish this complex immunoblot reactivity. To characterize further the cross-react ive proteins recognized in T. brucei-cytoskeletons by BS7 each was exc ised from preparative gels and used as an immunogen for antiserum prod uction. Two proteins, with apparent sizes around 43 and 47 kDa, produc ed antisera shown to be monospecific by immunoblotting total T. brucei flagellum preparations. Each of these detected the basal body-associa ted immunofluorescence in T. brucei. Identification of the smaller, 43 kDa, component as a basal body-associated product was supported by th e behaviour of a second monoclonal antibody, BBA4, which was also show n to detect the T. brucei basal body complex by immunofluorescence and immunoblots the 43 kDa polypeptide. These observations reveal new com ponents of the trypanosome cytoskeleton. Also, they provide a further example of an immunological approach for identification of interesting , rare components of the T. brucei cytoskeleton starting from a comple x mixture of proteins.