Evaluation of Recombinant Human Growth Hormone Secretion in E. Coli Using the L-Asparaginase Ii Signal Peptide

Background: in the recent years, there has been an increasing interest in secretory production of recombinant proteins, due to its various advantages compared with intracellular expression. signal peptides play a critical role in prosperous secretion of recombinant proteins. accordingly, different signal peptides have been assessed for their ability to produce secretory proteins by trial-and-error experiments. the aim of this study was to evaluate the effect of l-asparaginase ii signal peptide on the recombinant human growth hormone (hgh) protein secretion in the escherichia coli (e. coli) host. methods: cloning and expression of a synthetic hgh gene, containing l-asparaginase ii signal sequence was performed in e. coli bl21 (de3) using 0.1mm iptg as an inducer at 23c overnight. periplasmic protein extraction was performed using three methods, including osmotic shock, osmotic shock in the presence of glycine and combined lysozyme/ edta osmotic shock. afterwards, the hgh expression was determined by sdspage. results: based on experimentally obtained results, hgh protein is expressed as inclusion body even in the presence of l-asparaginase ii signal peptide. conclusion: therefore, this signal peptide is not effective for secretory production of the recombinant hgh.