The study focuses on the purification and characterization of adenylate cyclase activity associated with *Trypanosoma cruzi* sedimentable fractions. The enzyme was solubilized using non-ionic detergent Lubrol PX and 0.5 M-(NH₄)₂SO₄, and its hydrodynamic and molecular parameters were determined. A monoclonal antibody to *T. cruzi* adenylate cyclase was obtained, which inhibited cyclase activities from several lower eukaryotic organisms. The *T. cruzi* adenylate cyclase was further purified using this antibody in immunoaffinity chromatographic columns, resulting in a main polypeptide band with an apparent molecular weight (M_r) of about 56,000. The antibody specifically reacted with this band, indicating its specificity. The study also discusses the properties of adenylate cyclases from lower eukaryotic organisms, their similarities and differences with those from higher eukaryotes, and the role of regulatory factors in their activity.The study focuses on the purification and characterization of adenylate cyclase activity associated with *Trypanosoma cruzi* sedimentable fractions. The enzyme was solubilized using non-ionic detergent Lubrol PX and 0.5 M-(NH₄)₂SO₄, and its hydrodynamic and molecular parameters were determined. A monoclonal antibody to *T. cruzi* adenylate cyclase was obtained, which inhibited cyclase activities from several lower eukaryotic organisms. The *T. cruzi* adenylate cyclase was further purified using this antibody in immunoaffinity chromatographic columns, resulting in a main polypeptide band with an apparent molecular weight (M_r) of about 56,000. The antibody specifically reacted with this band, indicating its specificity. The study also discusses the properties of adenylate cyclases from lower eukaryotic organisms, their similarities and differences with those from higher eukaryotes, and the role of regulatory factors in their activity.