ABSTRACT
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. In this study, the fusion form of highly soluble rhPTH was expressed at high level in Escherichia coli [E. coli]. His[6]-thioredoxin as an extension for rhPTH improves the solubility of inclusion body. His[6]-thioredoxin-hPTH [1-34] was ligated into pET32alpha expression vector. The insertion of 5 amino acids [Asp-Asp-Asp-Asp-Lys] in the N-terminal of PTH made this protein to be digestable specifically by enterokinase enzyme. The fusion form of rhPTH was harvested and purified by immobilized affinity chromatography followed by digestion with enterokinase. Digested rhPTH was purified by applying on size exclusion and ion exchange chromatography to get the highest purity. The mass spectroscopy analysis shows rhPTH molecular weight was 4117.5 Da. The purity was measured by HPLC column which showed more than 97%. Bioassay analysis of rhPTH was performed on rat sarcoma cell UMR-106 in parallel with commercially available rhPTH, Forteo. The result was measured through immunofluorescence detection kit. The data showed that the potency of rhPTH was comparable with commercially available medicine. Thioredoxin was applied as a fusion partner for production of highly soluble rhPTH. This specific fusion partner increased protein solubility and decreased protease reactivity. Purification process was optimized for high recovery and for purity more than 99%. As its biological activity is comparable with marketed drug, this protein is qualified for biopharmaceutical usage
ABSTRACT
A healthcare system has been the most important priority for all governments worldwide. Biotechnology products have affected the promotion of health care over the last thirty years. During the last several decades, Iran has achieved significant success in extending healthcare to the rural areas and in reducing the rates of infant mortality and increasing population growth. Biomedical technology as a converging technology is considered a helpful tool to fulfill the Iranian healthcare missions. The number of biotechnology products has reached 148 in 2012. The total sales have increased to 98 billion USD without considering vaccines and plasma derived proteins in 2012. Iran is one of the leading countries in the Middle East and North Africa in the area of Medical biotechnology. The number of biotechnology medicines launched in Iran is 13 products until 2012. More than 15 products are in pipelines now. Manufacturers are expecting to receive the market release for more than 8 products by the end of 2012. Considering this information, Iran will lead the biotechnology products especially in area of biosimilars in Asia after India in next three years. The present review will discuss leading policy, decision makers' role, human resource developing system and industry development in medical biotechnology