LAUSR

Biologically active peptides and proteins have wide applications as therapeutic agents as well as diagnostics. Parathyroid hormone (PTH), a polypeptide secreted by the parathyroid chief cells has been found to be an effective therapeutic protein for the treatment of osteoporosis. PTH as an anabolic agent and a potent regulator of ionized calcium and phosphate plays a pivotal role in maintaining active vitamin D metabolite levels in the circulating blood. Though licensed PTH is available in two forms as teriparatide having 1–34 amino acids and intact hormone having 1–84 aminoacids, due to short plasma half-life and low activity, their therapeutic purpose has been limited. Protein engineering approaches like PEGylation, conjugation with antibody complexes, and fusion proteins as well as amino terminal modification of intact or truncated PTH has helped to develop PTH and its modified analogs with improved therapeutic value and multitude functions in various fields of medicine. This review covers the significant role of PTH in osteoblast signaling mechanism, regulation of PTH secretion and its transcription, modifications in PTH along with its functional efficacy in different medical areas.