Expression and purification of human mPGES-1 in E. coli and identification of inhibitory compounds from a drug-library

Human microsomal prostaglandin E synthase-1 (mPGES-1) is a membrane associated protein that catalyzes the conversion of prostaglandin H2 (PGH2) into prostaglandin E2 (PGE2). In this study, the expression of human mPGES-1 in E. coli was significantly enhanced by modifying the utility of specific codons and the recombinant mPGES-1 was efficiently purified to homogeneity. The Km and Vmax of the purified enzyme were determined and the trimeric state characterized by chemical cross-linking with glutaraldehyde. The purified mPGES-1 was used for the screening of a chemical library of bioactive or drug compounds to identify novel inhibitors, and oxacillin and dyphylline were identified as moderately inhibiting mPGES-1 with IC50 values of 100 and 200 μM, respectively. As these compounds competitively inhibited the catalysis of PGH2, their binding sites appeared to be located near the PGH2 binding pocket. [BMB reports 2008; 41(11): 808-813]