Partial purification and characterization of phosphotyrosyl-protein phosphatase(S) from human erythrocyte cytosol

• Published in: Biochemical and biophysical research communications Vol. 137; no. 1; pp. 566 - 572
• Main Authors: Clari, Giulio, Brunati, Anna Maria, Moret, Vittorio
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 29.05.1986; Elsevier
• Subjects: 4-Nitrophenylphosphatase - blood; Applied sciences; Chromatography, DEAE-Cellulose; Erythrocytes - enzymology; Exact sciences and technology; Humans; Other techniques and industries; Phosphoprotein Phosphatases - blood; Phosphotyrosine; Substrate Specificity; Tyrosine - analogs & derivatives; Tyrosine - metabolism
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/0006-291X(86)91248-9

Phosphotyrosyl-protein phosphatase activity of human erythrocyte cytosol can be resolved into two fractions by DEAE-cellulose chromatography followed by P-cellulose chromatography. Both 32P-Tyr-phosphatases are able to dephosphorylate 32P-Tyr of poly (Glu-Tyr) 4:1 but not angiotensin II and synthetic peptide Asp-Ala-Glu-Tyr-Ala-Ala-Arg-Arg-Gly, previously phosphorylated on tyrosine residues by rat spleen tyrosine-protein kinase. Both 32P-Tyr-phosphatase activities distinctly differ from either 32P-Tyr-phosphatase activity or “acid” and “alkaline” p-nitrophenylphosphatase activities with regard to catalytic and physico-chemical properties such as substrate specificity, chromatographic behaviour, response to various effectors.