FIGURE 1.

The time course of MKP5-catalyzed p38α/pTpY dephosphorylation reaction. The reaction mixture contained the standard phosphatase assay buffer (50 mm MOPS, pH 7.0, 100 mm NaCl, 0.1 mm EDTA, 10 mm MgCl₂, 100 μm MESG, 0.1 mg/ml purine nucleotide phosphorylase), and 1.7 μm bisphosphorylated p38α. The absorption at 360 nm was recorded following the addition of 186 nm MKP5 at 25 °C.