Trypanosoma cruzi epimastigote forms possess a Ca(2+)-calmodulin dependent protein kinase

Trypanosoma cruzi epimastigote forms showed a tightly bound Ca(2+)-calmodulin-dependent protein kinase activity, which could be partially extracted from membranes and axonemes. The enzyme is constituted by subunits which were autophosphorylated in the absence of exogenous substrates. An antibody against CaM kinase II recognized a Ca(2+)- or Ca(2+)-CaM-dependent conformational epitope in these fractions. The detected bands were of molecular weights similar to the alpha and beta subunits of the corresponding bovine brain enzyme (60 and 50 kDa). Studies using [125I]CaM revealed the presence of a CaM-binding domain. These experiments confirm that the parasite possesses a particulate CaM kinase with characteristics similar to the bovine brain enzyme.