Description_x000D_ Amino Acid Sequence_x000D_ Ser-Glu-Ile-Gln-Leu-Met-His-Asn-Leu-Gly-Lys-His-Leu-Asn-Ser-Met-Glu-Arg-Val-Glu-Trp-Leu-Arg-Lys-Lys-Leu-Gln-Asp-Val-His-Asn-Phe_x000D_ Application_x000D_ Parathyroid hormone (PTH) is an 84 amino acid hormone involved in calcium regulation in counteraction to calcitonin. PTH regulates serum phosphate levels and vitamin D biosynthesis. N-terminal peptides of PTH are used to elicit and study a wide variety of responses in target cells. PTH N-terminal peptides include: PTH (1-34); [Nle8,18,Tyr34]-PTH 1-34; PTH (2-34); [Nle8,18,Tyr34]-PTH (2-34); PTH (3-34); [Nle8,18,Tyr34]-PTH (3-34); PTH (4-34) and PTH (5-34).