background: parathyroid hormone (pth) secreted by parathyroid glands regulates the metabolism of calcium and phosphorus in bone and kidney. thereby, it can stimulate bone formation, and is a promising agent in the treatment of osteoporosis. mature form of pth consists of 84 amino acids; however, the first 34 residues of pth cover the majority of hormonal action. methods: in this study, the fusi...