The production of Ara h 2 was enhanced significantly with the new BL21-Codon Plus (DE3)-RIL cells (Figure 1C), compared to the pQE/M15 system (Figure 1A) and to the conventional BL21-Gold(DE3) cell expression system (Figure 1B). The highest amount of recombinant protein was achieved by selecting an overnight incubation at 22C after IPTG induction.
The final yield of soluble recombinant Ara h 2 was estimated as 5 mg/L of culture, which is 100 times greater when compared to the 50 g achieved by the pQE/M15 expression system.
It is possible to make large quantities of high-quality heterologous proteins that are otherwise difficult to express in conventional E.coli hosts. When low-expression yields or low-quality recombinant protein is due to rare codon usage, BL21-CodonPlus (DE3)-RIL cells are the hosts of choice. We used these special cells and greatly increased the expression yield of the major peanut allergen Ara h 2, which contains 12% of the rare AGG/AGA codons in its message.
A 10-ml culture of each of the expression experiments was induced by adding 1
mM IPTG, then incubation commenced at three different temperatures (22C,