R25C parathyroid hormone

R25C parathyroid hormone (R25CPTH) is a parathyroid hormone (PTH) analog containing an arginine-to-cysteine substitution at position 25 of the mature polypeptide. Originally identified as a naturally occurring mutation in patients with familial idiopathic hypoparathyroidism who paradoxically exhibited increased bone mineral density, R25CPTH is being investigated as a bone anabolic therapy for osteoporosis and bone regeneration. The R25C mutation alters the hormone's conformation and its interaction with the parathyroid hormone-1 receptor (PTH1R), decoupling the anabolic and catabolic actions of PTH. Specifically, R25CPTH forms disulfide-bonded dimers that act as partial agonists at PTH1R, stimulating bone formation with a reduced risk of hypercalcemia compared to wild-type PTH analogs like teriparatide.

Other names

Cys25-PTHCys-25-PTHCys 25-PTHR25C-PTHR-25C-PTHR 25C-PTHR25CPTHR-25CPTHR 25CPTHR25CPTH(1-34)R25CPTH(1-84)dimeric R25C PTH(1-34)dimeric R25CPTH(1-34)