Efficient production of recombinant PP2A at a low temperature using a baculovirus expression system.

Protein phosphatase 2A (PP2A) is an enzyme useful for detecting several natural toxins represented by okadaic acid and microcystins. We found that the production of the recombinant human PP2A catalytic subunit (rhPP2Ac) in High Five insect cells could markedly increase when the cells were cultured at 19 °C instead of 27 °C used under conventional conditions. The yield and purity of the enzyme increased four- and three-folds, respectively. The benefit of the altered culturing temperature was observed with the recombinant human protein phosphatase 2B but not 2Cα. The different responses among the enzymes suggest the involvement of an enzyme-specific mechanism that leads to the catalytic subunit overexpression. This is the first report to produce rhPP2Ac at a temperature lower than that used under conventional culture conditions (27 °C) used in the baculovirus expression system with High Five insect cells.