Effects of Growth Medium on Extracellular Secretion of Human Epidermal Growth Factor in Escherichia coli by Co-expression with Bacillus cereus Phospholipase C

Abstract

Human Epidermal Growth Factor (hEGF) is a small, mitotic growth polypeptide that promotes the proliferation of various cells and is widely applied in clinical practices, especially in therapeutic uses of wound healing. Since it has a lot of benefits, production of recombinant hEGF (rhEGF) in a large scale is needed. Some methods have been used in this protein production, one of them was the production of rhEGF using extracellular secretion in Escherichia coli. Previous research have been done using co-expression method with phospholipase C from Bacillus cereus to increase the amount of rhEGF. Phospholipase C B. cereus have been used in several protein expression and was proved that it could increase the secretion of recombinant protein through hydrolytic mechanism of cell membrane. In addition, growth condition is one of some major factors which can affect the yields of produced protein. Different compositions of bacterial growth medium often lead to different result. This paper studies how rich-nutrient Terrifict Broth (TB) medium and Luria Bertani (LB) medium produced different rhEGF results when it was co-expressed with phospholipase C B. cereus. rhEGF was characterized using SDS-PAGE and confirmed by western blot using anti-mouse EGF, and its concentration was measured using ELISA. rhEGF was successfully characterized after co-expression in TB medium and the concentration was 503.48 μg/mL. rhEGF was better produced in TB medium rather than in LB medium since TB medium has richer composition.