Thyrocalcitonin. II. Structure of alpha-thyrocalcitonin

The highly active peptide hormones isolated from pig thyroids – i.e. α-thyrocalcitonin and its sulfoxide, containing 32 amino acid residues – were subjected to sequence studies using chemical and enzymatic methods. On the basis of these studies the following structure was derived for α-thyrocalcitonin: In the α-thyrocalcitonin sulfoxide (designated formerly as β-thyrocalcitonin) the methionine residue is replaced by methionine sulfoxide.