Abstract: The purpose of the invention is to provide an activated protein phosphatase 2A (PP2A) in large quantities with high purity by a genetic engineering and to provide a method for producing a heterodimer derivative of PP2A which comprises infecting insect cultured cells with a baculovirus in which a cDNA encoding the catalytic subunit of PP2A carrying a first tag is integrated together with another baculovirus in which a cDNA encoding the A subunit of PP2A carrying a second tag is integrated, incubating the infected cells, disrupting the incubated cells to obtain a disrupted cell suspension, and then purifying the disrupted cell suspension with a solid phase carrying a substance capable of binding to the first tag and another solid phase carrying a substance capable of binding to the second tag, characterized in that the insect cells infected with the baculovirus are incubated at a temperature of from 18 to 22° C.

Abstract: The purpose of the invention is to provide an activated protein phosphatase 2A (PP2A) in large quantities with high purity by a genetic engineering and to provide a method for producing a heterodimer derivative of PP2A which comprises infecting insect cultured cells with a baculovirus in which a cDNA encoding the catalytic subunit of PP2A carrying a first tag is integrated together with another baculovirus in which a cDNA encoding the A subunit of PP2A carrying a second tag is integrated, incubating the infected cells, disrupting the incubated cells to obtain a disrupted cell suspension, and then purifying the disrupted cell suspension with a solid phase carrying a substance capable of binding to the first tag and another solid phase carrying a substance capable of binding to the second tag, characterized in that the insect cells infected with the baculovirus are incubated at a temperature of from 18 to 22° C.