Protein Phosphatase Inhibitor 2

Liquid. In 50 mM HEPES, 1 mM EDTA, 50% glycerol, 0.01% BRIJ^® 35 Detergent, pH 7.0. AVOID FREEZE/THAW CYCLES. Recombinant, rabbit PPI2 expressed in E. coli. A 204-amino acid, heat-stable protein that specifically inhibits the catalytic subunit of protein phosphatase 1 (IC₅₀ = 2 nM). Useful for distinguishing type 1 from type 2 protein phosphatases. A good substrate for CKI, CKII, GSK3b, and PKA. Specific activity: ≥500,000 units/mg protein. One unit is defined as the amount of PPI-2 that will inhibit 0.01 units of PP1 by 50%. One unit of PP1 is defined as the amount of enzyme that will release 1.0 nmol phosphate from phosphorylase a per min at 30°C, pH 7.0 Purity: ≥95% by SDS-PAGE. Contaminants: Phosphatases, proteases: none detected.

Ref.: Park, I., et al. 1994. J. Biol. Chem. 269, 944. Zhang, Z., et al. 1992. J. Biol. Chem. 267, 1484. Cohen, P. 1991. Methods Enzymol. 201, 389.