Expression and optimization of anti-AFB1 scFv in Escherichia coli
抗黄曲霉毒素B1单链抗体在大肠杆菌中的表达及优化

Abstract: 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.