Method for the determination of the activity of specific phosphotyrosine phosphatases and specific effectors thereof in intact cells

摘要

For the determination of the activity of a specific protein tyrosine phosphatase (PTPase) in intact cells one incubates intact cells which contain a substrate of the specific PTPase, if desired after stimulating the substrate phosphorylation, with a substance which can penetrate into the intact cells and can selectively inhibit phosphorylation of the substrate, the degree of phosphorylation of the substrate is measured, if desired several times, at various time points and the activity of the specific PTPase is determined from the measured degree of phosphorylation of the substrate. An additional measurement is carried out in the presence of a test substance to determine effectors of the specific PTPase and the effector action of the test substance is determined by comparing the degrees of phosphorylation.