response surface methodology approach to optimize the expression of thioredoxin-mog fusion protein

Background: the n-terminal domain of the myelin oligodendrocyte glycoprotein (mog) has been shown to generate experimental autoimmune encephalomyelitis (eae), an animal model of ms. a considerable amount of mog must be accessible for eae induction. here, for the first time, response surface methodology-box-behnken (rsm-bbd) was employed to identify the ideal culture conditions for causing escherichia coli (e. coli) bl21 to overproduce the thioredoxin-mog (trx-mog) fusion protein. the rsm method is a powerful, efficient, and reliable alternative to the one-factor-at-a-time (ofat) method in optimizing process variables, allowing for a smaller number of experimental runs, investigating variable interaction, and being cheaper and less time-consuming. methods: here, using the 29 experimental assays, the direct and indirect effects of factors including post-induction time, iptginducer concentration, pre-induction optical density, and post-induction temperature on the protein expression level content were evaluated. results: the proposed quadratic model demonstrated a significant effect of the two variables a (time) and c (temperature) on protein synthesis. an inducer concentration of 0.491 mm, the pre-induction optical density (od600) of 0.8, and a temperature of 23 °c for 23.878 hours were found to be the best growth conditions for high yield trx-mog synthesis. the optimum protein concentration was attained (163.96 µg/ml) and was within the range of (200.04 µg/ml), which was the value predicted. conclusion: the study concluded that rsm optimization effectively increased the production of trx-mog in e. coli, which could have the potential for large-scale fermentation.