Expression of human estrogen receptor alpha and beta in Escherichia coli

Estrogen participates in many life activities through combination with estrogen receptor alpha (ERalpha) or estrogen receptor beta (ERbeta) in the body. In order to establish an in vitro estrogen-like compound screening model, the coding region of human ERalpha and ERbeta was separately constructed into pET32-ERalpha and pET43-ERbeta prokaryotic expression vector and water-soluble recombinant ERalpha and ERbeta proteins were expressed in Escherichia coli strain BL21. Western blotting revealed that both recombinant proteins have estrogen receptor binding sites. The proteins were purified using S-Tag affinity Purification Kit and digested with enterokinase to get the ERalpha and ERbeta proteins. About 0.90 mg of ERalpha and 0.65 mg of ERbeta were obtained at the concentration of 0.181 and 0.131 mg x mL(-1), respectively.