Salmon Calcitonin And Calcitonin Gene-related Peptide Gene Prokaryotic Expression

China has a continually aging population. As a result osteoporosis and cardiovascular disease are becoming more common. Salmon calcitonin (sCT) is a natural calcitonin with the highest effectiveness to treat osteoporosis. Calcitonin gene-related peptide (CGRP) is the most powerful endogenous vasodilator peptide and the first choice for the treatment of cardiovascular disease. For clinical treatment of common diseases in old people such as osteoporosis and cardiovascular disease, accessing a double-effect of pharmaceutical proteins has become a growing concern with the increasing need for the Salmon calcitonin and Calcitonin gene-related peptide.In this study, we used a genetically engineered method to synthesize the fusion of genes calcitonin gene-related peptide and salmon calcitonin. These genes were cloned into a pGEX-6p-1 expression vector. The recombinant plasmid was transformed into E. coli BL21. Using IPTG as an inducing agent, we analyzed and comprised the final concentration of protein expression with different induction temperatures, different time and different IPTG induction conditions to determine the optimal conditions for inducible expression.The results indicated that Escherichia coli expression vector pGEX (CGRP/msCT) was successfully constructed. The best target protein-induced temperature was 37℃, the best IPTG final concentration was 0.2mmol/L, and the best induced time was 5 hours. The final concentration of protein expression can reach 32.11% of the total bacterial protein.