I1PP2A-GST (1 μg)

Source: Recombinant human produced GST-tagged in E. coli

Purity: > 90% by SDS-PAGE, apparent Mr ~ 58-kDa

Supplied: 1 μg in 50 μl 50 mM Tris-HCl pH 7.0 buffer containing 14 mM β-mercaptoethanol, 1 mM benzamidine, 0.1 mM phenylmethanesulfonyl fluoride, 1 mM EDTA, 0.1% Brij-35 and 10% glycerol. Maintain preparations in aliquots at -70° C. Avoid repeated thawing.

Synonyms: GST-I1PP2A; Protein Phosphatase 2A Inhibitor Protein 1; PHAP-I; p32/33; LANP

Background: The PP2A inhibitor proteins, I1PP2A and I2PP2A, were discovered in the laboratory of GloboZymes founder Dr. Zahi Damuni while he was a faculty member in the Department of Cellular and Molecular Physiology at Penn State College of Medicine. There has been progress since that time in numerous laboratories around the world demonstrating further the significance of these proteins in various diseases including cancer and Alzheimers, for example. I1PP2A, also termed PHAP-I, p32/33 and LANP, is highly expressed in some cancers. Purified preparations of the protein inhibit all forms of protein phosphatase 2A (PP2A, GLO130-GLO132) tested to date in a substrate-selective manner. The purified preparations inhibit PP2A potently (ki ~ 0.1 - 0.5 nM) with myelin basic protein (MBP, GLO126-010MGLO126-025) and histone H1 but not with casein as substrate. In contrast, the preparations stimulate PP1 (GLO133-001). I1PP2A undergoes phosphorylation on serines and tyrosines in cells. The functional significance of the serine phosphorylation remains to be determined. Tyrosine phsophorylation of I1PP2A occurs in response to the antiproliferative lectin, Jacalin and causes the dissociation of I1PP2A from PP2A and the activation of the phosphatase.

GloboZymes I1PP2A GST-tagged preparations maintains all known activities of the native I1PP2A protein (GLO140-001) tested to date. The GST-tagged preparations are effective for binding and pull-down studies.


  1. Li M, Makkinje A, Damuni Z. (1996) "Molecular identification of I1PP2A, a novel potent heat-stable inhibitor protein of protein phosphatase 2A" Biochemistry 35, 6998-7002
  2. Vaesen, M. et al (1994) "Purification and characterization of two putative HLA class II associated proteins: PHAPI and PHAPII" Biol Chem Hoppe Seyler 375, 113-126
  3. Malek, S. N. et al (1990) "Identification and preliminary characterization of two related proliferation-associated nuclear phosphoproteins" J Biol Chem 265, 13400-13409
  4. Li, M., Damuni, Z. (1998) "I1PP2A and I2PP2A: Two Potent Protein Phosphatase 2A-Specific Inhibitor Proteins" Methods Mol Biol  93, 59-66
  5. Katayose, Y. et al (2000) "Protein Phosphatase 2A Inhibitors, I1PP2A and I2PP2A, Associate with and Modify the Substrate Specificity of Protein Phosphatase 1" J Biol Chem 275, 9209-9214
  6. Yu L-G et al (2004) “Protein Phosphatase 2A, a negative regulator of the ERK signaling pathway, is activated by tyrosine phosphorylation of Putative HLA Class II-associated Protein I (PHAPI)/pp32 in response to the antiproliferative lectin, Jacalin” J Biol Chem 279, 41377-41383


Related Products:   I1PP2A  ♦  I1PP2A GST (5 μg)  ♦  Anti-I1PP2A (50 μg)  ♦  Anti-I1PP2A (100 μg)  ♦  I1PP2A Detection Kit  ♦  I2PP2A  ♦  I2PP2A GST (1 μg)  ♦  I2PP2A GST (5 μg)  ♦  I2PP2A(β)  ♦  PP2A1 ♦  PP2A2 ♦  PP2AC ♦  PP1C ♦ MBP (10 mg)  ♦ MBP (25 mg)

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