Drosophila melanogaster S2 cells are more suitable for the production of recombinant COX-1 than Trichoplusia ni BTI TN-5B1-4 cells

Recombinant human cyclooxygenase-1 (COX-1) was expressed from stably transfected Trichoplusia ni BTI TN-5B1-4 (TN-5B1-4) and Drosophila melanogaster S2 cells. Two kinds of recombinant COX-1 with molecular weights (MWs) of 68 and 74 kDa were expressed in the intracellular fractions of stably transfected TN-5B1-4/ COX-1 and S2/COX-1 cells, due to glycosylation. The recombinant COX-1 secreted to medium fractions has a MW of 72 kDa. Recombinant COX-1 in the intracellular fractions was purified to homogeneity using a one-step Ni-NTA affinity fractionation method. Recombinant COX-1 purified from TN-5B1-4/COX-1 and S2/COX-1 cells contained 11,389 and 33,850 Unit/mg of specific peroxidase activity, respectively. The maximum productions of intracellular recombinant COX-1 were 1.7 and 5.6 μg/10⁷ cells in the T-flask cultures of TN-5B1-4/COX-1 and S2/COX-1 cells, respectively. Taken together, our findings indicate that S2 cells can be more suitable system to produce recombinant COX-1, compared to TN-5B1-4 cells.