规格: | 98% |
分子量: | 1328.28 |
包装 | 价格(元) |
1mg | 询价 |
5mg | 询价 |
10mg | 询价 |
Background:
EGF Receptor Substrate 2 (Phospho-Tyr5) is a biologically active peptide derived from an autophosphorylation site (Tyr992) of epidermal growth factor receptor (EGFR).
DADEpYLIPQQG is a generalized PTPase substrate. Both CAV GST-VP2 and TLMV GST-ORF2 are shown to have PTPase activity using both ENDpYINASL and DADEpYLIPQQG. Steady state activities for the reaction of 5 μg of CAV GST-VP2 with ENDpYINASL and DADEpYLIPQQG are 100 and 208%, respectively, of those seen for 2 units of TC-PTP[1]. In the context of DADEpYLIPQQG, the minimal sizes recognized by PTPα are either ADEpYLI or DADEpY-NH2. The kcat/Km value for the parent peptide DADEpYLIPQQG (EGFR988-998) is 1090-fold higher than Tyr(P)[2].
[1]. Peters MA, et al. Chicken anemia virus VP2 is a novel dual specificity protein phosphatase. J Biol Chem. 2002 Oct 18;277(42):39566-73. Epub 2002 Jul 31. [2]. Wu L, et al. Comparative kinetic analysis and substrate specificity of the tandem catalytic domains of the receptor-like protein-tyrosine phosphatase alpha. J Biol Chem. 1997 Mar 14;272(11):6994-7002.
Protocol:
Kinase experiment: | Briefly, the assays are performed in 50 μL volumes in a microtiter plate using the generalized PTPase substrates ENDpYINASL and DADEpYLIPQQG (where pY represents phosphotyrosine) and assay buffer containing 25 mM Tris-HCl (pH 7.4), 50 mM NaCl, 2 mM EDTA, 5 mM dithiothreitol, 0.01% Brij 35, and 1 mg of bovine serum albumin/mL. The reactions are started by the addition of 5 μg of either CAV GST-VP2, GST, CAV GST-VP2 containing the C95S mutation, or TLMV GST-ORF2 or 2 units of the positive control T cell protein-tyrosine phosphatase (TC-PTP) in assay buffer. Control reactions are assayed with either ENDpYINASL substrate alone, DADEpYLIPQQG substrate alone, CAV GST-VP2 without substrate, CAV GST-VP2 containing the C95S mutation without substrate, TLMV GST-ORF2 without substrate, TC-PTP without substrate, or assay buffer with neither enzyme nor substrate. A phosphate standard curve is derived using a supplied phosphate standard. The reactions are terminated by the addition of the malachite green detection reagent. |
参考文献: [1]. Peters MA, et al. Chicken anemia virus VP2 is a novel dual specificity protein phosphatase. J Biol Chem. 2002 Oct 18;277(42):39566-73. Epub 2002 Jul 31. |
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