Overexpression and purification of recombinant eel calcitonin and its phylogenetic analysis.

Calcitonin (CT), a peptide hormone that is widely used for the treatment of osteoporosis, Paget's disease, hypercalcemic shock and chronic pain in terminal cancer patients, is produced by the para-follicular cells of the thyroid gland in mammals and by the ultimobranchial gland of birds and fish. Fish calcitonin, like eel calcitonin (eCT), is more potent and longer lasting than human CT and is one of the many bioactive peptides that require C-terminal amidation for full biological activity. In this study we describe the over-expression and over-production of C-terminal amidated eCT in recombinant Streptomyces avermitilis. A phylogenetic analysis was performed with all the known CT amino acid sequences.