Expression of SCT-OGP Fusion Protein and Its Potential Role as Osteoporosis Therapy Drugs

Osteoporosis is a disease of bone metabolic disorder and its occurrence has increased sharply in old people. Calcitonin (CT) is a peptide hormone containing 32 amino acids that inhibit osteoclast's activity. Osteogenic Growth Peptide (OGP) is a peptide hormone with 14 amino acids. It is an autocrine mitogen for osteoblastic and fibroblastic cells, and has anabolic activity. Six SCT and OGP DNA segments were chemically synthesized and ligated into a yeast expression vector pPIC9. The recombinant plasmid was transformed into Pichia pastoris GS115. Finally, by screening, two stable SCT-OGP high expression clones were obtained. Purified protein stimulated the proliferation of osteoblastic and fibroblastic cells and also stimulated serum ALP activity while decreased serum calcium level in mice animal models, demonstrating its potential role in osteoporosis therapy.