An individual catalytic component of calmodulin-independent adenylate cyclase has been isolated from bovine brain cortex. Affinity chromatography on an immunosorbent was used. The amino acid sequence of adenylate cyclase as well as the corresponding nucleotide sequence of the cDNA has been determined. cDNA of adenylate cyclase encodes a protein consisting of 834 amino acid residues and the signal peptide (19 amino acid residues). A series of adenylate cyclase isoforms has been found. A homology between adenylate cyclases from bovine brain, E. coli and Bordetella pertussis has been revealed.