[Effects of matrine on the activity of protein tyrosine kinase and phosphatase in K562 cells].

Background & Objective: The differentiation of K562 cells can be induced by a given concentration of matrine. This study was designed to investigate the mechanism of signal transduction in induced differentiation of K562 cells.
Methods: ELISA coupled with streptavidin-biotin system was used to dynamically detect the activity of protein tyrosine kinase and phosphatase in the cytoplasm and the membrane of K562 cells treated by matrine.
Results: Matrine inhibited the activity of protein tyrosine kinase in K562 cells, and the inhibitive effect depended on matrine of the concentration within 0.1 mg/ml. The effects of different concentration of matrine on the protein tyrosine phosphatase activity had no significant difference. Activity of the protein tyrosine phosphatase decreased transiently accompanied with the activity of the protein tyrosine kinase in K562 cells treated with 0.1 mg/ml matrine.
Conclusions: The change of protein tyrosine kinase activity is involved in the differentiation of K562 cells induced by matrine. The tyrosine kinase activity in cell membrane decreased more rapidly than that in cell cytoplasm, suggesting there be a transmembrane signal transduction. The change of tyrosine phosphatase activity following the kinase indicates the real time regulation of phosphorylation and dephosphorylation. Moreover, the inhibitory effect of matrine on the protein tyrosine kinase shows the characters of specificity and saturation, suggesting the exist of matrine-associated receptor in K562 cells.