Assay of phosphotyrosyl protein phosphatase using synthetic peptide 1142–1153 of the insulin receptor
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...
Saved in:
Published in | FEBS letters Vol. 237; no. 1; pp. 137 - 140 |
---|---|
Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Amsterdam
Elsevier B.V
12.09.1988
Elsevier |
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | 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. |
---|---|
Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0014-5793 1873-3468 |
DOI: | 10.1016/0014-5793(88)80187-X |