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New Calcitonin Isolated from the Ray, Dasyatis akajei
Abstract:
Calcitonin causes hypocalcemia by inhibiting the resorption of calcium from the bone in mammals. Calcitonin has now been isolated from the ultimobranchial gland of a cartilaginous fish, the ray (Dasyatis akajei), and its amino acid has been determined to be H-Cys-Thr-Ser-Leu-Ser-Thr-Cys-Val-Val-Gly-Lys-Ser-Gln-Gln-Leu-His-Lys-Leu-G ln-Asn-Ile-Gln-Arg-Thr-Asp-Val-Gly-Ala-Ala-Thr-Pro-NH2. Although its basic structure is well conserved, the amino acid sequence of ray calcitonin is considerably different from that of other calcitonins sequenced to date. Because the ray lacks calcified bones, an examination of the effect of calcitonin in this fish may elucidate a new role for calcitonin in vertebrates.
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