Analysis of phosphatase activity of GST-Cdc25A^128His and GST-Cdc25A^128Gln fusion proteins.

GST fusion proteins were purified and tested for phosphatase activity. Equivalent amounts of GST-CDC25A^128His, GST-CDC25A^128Gln, and GST were incubated with 40 mM pNPP for the indicated times (see “Materials and methods”). Reactions were stopped, and absorbance at 410 nm was measured. The graph is representative of 3 independent experiments. Each time point was done in triplicate. Data are averages ± SD.