Protein Expression with Signal Peptide Using Escherichia coli

Abstract

As we know that Escherichia coli is one of the most widely used hosts for the production of recombinant proteins. Escherichia coli could express protein and secret it to the extracellular medium, to the periplasmic production, intracellular production as IBs (insoluble form), and intracellular and soluble production. By dividing into soluble expression and insoluble expression (inclusion body) there are some different things that should be noted. Insoluble expression could be high productivity in culture process, low impurity, low endotoxin level (mostly removed during IBs recovery) but its needs for refolding process. For the soluble expression it could be low productivity in culture process, high impurity, no need to solubilization and refolding but high endotoxin level. Overexpressed proteins are often produced in the form of inclusion bodies, from which biologically active proteins can only be recovered by complicated and costly denaturation and refolding processes. Furthermore, the final yields of these soluble refolded proteins are usually very low, due mainly to protein aggregation resulting from interactions between the hydrophobic regions of the proteins (Choi and Lee 2004). This is because Escherichia coli does not have PTM processing. To prevent this condition, strategies for secretory and extracellular production of recombinant proteins using E. coli could be used (Choi and Lee 2004). ...