Cell and Tissue Journal

Abstract Aim: In this century, the production of recombinant drugs such as growth hormone has increased. Different problems existed in the expressions of cytoplasmic and Periplasmic types of growth hormone. Therefore, finding a way to optimize expression is very necessary. In this study, we optimized expression of growth hormone in the form of solution state by trx-tag method. This method increase protein expression (Periplasmic problem) and also prevents formation of inclusion body (problem cytoplasmic).
Material and methods: Gene synthesis and gene cassette was done in pET 32a expression vector. Gene cassette contains trx tag for protein solubilization, His tag for purification and enterokinase for separate rHgh from previous tags.
 Results: After cloning the gene in vector, its expression was confirmed by Western blot technique. The results showed that the expression of fusion protein was done well.
Conclusion: the obtained finding proved that protein can be soluble by Trx-tag and increased its expression levels. Moreover, better results can be achieved in the fermentation and downstream processing.