Designing recombinant Escherichia coli strain for expression of Interleukin-3 and Interleukin-11 in fusion form with PELB
Keywords:Escherichia coli, Interleukin-3 và Interleukin-11, Isopropylthio-β-galactoside (IPTG), pelB leader.
Interleukin-3 và Interleukin-11 are multifunctional cytokine, which modulates the proliferation, differentiation and maturation of various types of hematopoietic cells. Genes coding for IL-3 and IL-11 (NM_000588 and NM_000641 from GenBank) linked with pelB leader and restriction sequences of NdeI (5’end), NotI (3’end) were synthesized and then introduced into a cloning vector pUC57. The gene cassets were incorporated into pET22b(+) at restriction sites for expression of il3 and il11 genes in E. coli BL21. Following induction with 0.5 mM IPTG at 37oC, a band of 15 kD, corresponding to the size of IL-3 protein (cleavage of PelB signal sequence) and another band of about 18 kD, corresponding to the size of IL-3 protein in fusion with PelB. IL-11 protein was expressed with a very faint band of about 19 kD, corresponding to the human IL-11 size.