Assay of phosphotyrosyl protein phosphatase using synthetic peptide 1142–1153 of the insulin receptor
Authors:
- Graham J. SaleGSGraham J. Sale
- 12 September 1988
- journal article
- Published by Wiley in FEBS Letters
- Vol. 237 (1-2) , 137-140
Abstract
Synthetic peptide 1142–1153 of the insulin receptor was phosphorylated on tyrosine by the insulin receptor and found to be a potent substrate for dephosphorylation by rat liver particulate and soluble phosphotyrosyl protein phosphatases. Apparent K m values were 5 μM. V m values (nmol phosphate removed/min per mg protein) were 0.62 (particulate) and 0.2 (soluble). This corresponds to 80% of total activity being membrane‐associated, indicating that membrane‐bound phosphatases are important receptor phosphatases. The phosphatase activities were distinct from acid and alkaline phosphatase. In conclusion peptide 1142–1153 provides a useful tool for the further study and characterization of phosphotyrosyl protein phosphatases.Keywords
This publication has 24 references indexed in Scilit:
- Calcineurin-mediated dephosphorylation of the human placental membrane receptor for epidermal growth factor urogastroneBiochemistry, 1985
- A major phosphotyrosyl-protein phosphatase from bovine heart is associated with a low-molecular-weight acid phosphataseArchives of Biochemistry and Biophysics, 1985
- Human insulin receptor and its relationship to the tyrosine kinase family of oncogenesNature, 1985
- A phosphotyrosyl‐protein phosphatase activity associated with acid phosphatase from human prostate glandEuropean Journal of Biochemistry, 1984
- Multiple forms of phosphotyrosyl- and phosphoseryl-protein phosphatase from cardiac muscle: Partial purification and characterization of an EDTA-stimulated phosphotyrosyl-protein phosphataseArchives of Biochemistry and Biophysics, 1983
- An acid phosphatase in the plasma membranes of human astrocytoma showing marked specificity toward phosphotyrosine protein.Proceedings of the National Academy of Sciences, 1982
- Insulin stimulates tyrosine phosphorylation of the insulin receptor in a cell-free systemNature, 1982
- Detection of a novel mammalian protein phosphatase with activity for phosphotyrosineFEBS Letters, 1981
- Isolation of phosphorylated peptides and proteins on ion exchange papersAnalytical Biochemistry, 1978
- Separation of Two Phosphorylase Kinase Phosphatases from Rabbit Skeletal MuscleEuropean Journal of Biochemistry, 1976