EXPRESSION OF BOVINE LUNG PROSTAGLANDIN-F SYNTHASE IN ESCHERICHIA-COLI

The full-length bovine lung prostaglandin(PG) F synthase cDNA was constructed from partial cDNA clones and ligated into bacterial expression vector pUC8 to develop expression plasmid pUCPF1. This plasmid permitted the synthesis of bovine lung PGF synthase in Escherichia coli. The recombinant bacteria overproduced a 36-KDa protein that was recognized by anti-PGF synthase antibody, and the expressed protein was purified to apparent homogeneity. The expressed protein reduced not only carbonyl compounds including PGD2and phenanthrenequinone but also PGH2; and the Km values for phenanthrenequinone, PGD2, and PGH2of the expressed protein were 0.1, 100, and 8μM, respectively, which are the same as those of the bovine lung PGF synthase. The protein produced PGF2αfrom PGH2, and 9α,11β-PGF2from PGD2at different active sites. Moreover, the structure of the purified protein from Eschericia coli was essentially identical to that of the native enzyme in terms of C-terminal sequence, sulfhydryl groups, and CD spectra except that the nine amino acids provided by the lac Z′ gene of the vector were fused to the N-terminus. These results indicate that the expressed protein is essentially identical to bovine lung PGF synthase. We confirmed that PGF synthase is a dual function enzyme catalyzing the reduction of PGH2and PGD2on a single enzyme and that it has one binding site for NADPH. © 1991 Academic Press, Inc.