Sakai K, Sada K, Tanaka Y, Kobayashi T, Nakamura S, Yamamura H
Department of Biochemistry, Fukui Medical School, Japan.
Biochem Biophys Res Commun. 1988 Aug 15;154(3):883-9. doi: 10.1016/0006-291x(88)90222-7.
In vitro regulation of cytosolic protein-tyrosine kinase from porcine spleen (CPTK-40) by various positive or negative charged compounds was studied. Spermine and spermidine stimulated the activity of CPTK-40 about two-fold using (Val5)angiotensin II as a substrate. This stimulation was not specific for the peptide but was also observed in the case of tubulin phosphorylation indicating a direct effect of these compounds on the enzyme itself. On the contrary, negative-charged polysaccharides were shown to be strong inhibitors of CPTK-40. The possibility of the physiological regulation of CPTK-40 by these compounds is briefly discussed.
