Objective: A drawback of the expression of single chain antibody fragment (scFv) in prokaryotic system is the protein accumulation in the cytoplasm as inclusion body. We aimed at high-level production of an anti-aflatoxin B1 scFv in functional form.
Methods: The gene of scFv-H4 was cloned into pET22b vector and transformed into E. coli BL21(DE3) and Origami (DE3),respectively. The amount of functional scFv-H4 was optimized in terms of IPTG concentration and induction temperature.
Results: scFv-H4 could be expressed in both BL21(DE3) and Origami (DE3). Compared with BL21(DE3), Origami(DE3) could express multifunctional scFv-H4 (35 mg/mL) and less in inclusion body (11% of the total expression). The expression of scFv-H4 was significantly affected by induction temperature rather than IPTG concentration.
Conclusion: The pET22b could be used for high-level expression of the functional scFv-H4 in Origami (DE3), which has an oxidative cytoplasm. In addition,the induction at low temperature avoided the formation of inclusion body.