Atrial natriuretic factor: purification of active peptides, cloning of cDNA and determination of structures of active peptides and precursors.

Four peptides possessing both natriuretic and smooth muscle relaxant activities were purified from rat heart atrium and their amino acid sequences were determined. All contained a common sequence which contains a macro-ring structure formed by 17 amino acid residues and a disulphide bridge. The major atrial peptide in the atrium was identified as that containing 31 amino acid residues. The cDNA of the atrial peptide precursor was cloned and its nucleotide sequence determined. The amino acid sequence of the precursor deduced from the nucleotide sequence contained 152 residues and a potential signal peptide sequence characteristic of secretory polypeptides.