Effects of tyrphostins on activity of casein kinase II from rat liver.
OBJECTIVE
To investigate the effects of tyrphostins, (AG213, AG1394, AG114, AG1109, AG555) on the activity of casein kinase (CK) II.


METHODS
CK II was partially purified from rat livers by sequential DE52 and heparin-Sepharose chromatography. CK II activity was assayed by incubating CK II with dephosphorylated casein and [gamma-32 P]ATP.


RESULTS
AG213 inhibited the activity of CK II with IC50 44.7 mumol.L-1 (41.5-47.9 mumol.L-1), and AG1394 (144 mumol.L-1) strongly inhibited the activity of CK II with an inhibitory ratio of 89%. AG114 (174 mumol.L-1) and AG1109 (126 mumol.L-1) had inhibitory effects on the activity of CK II (p < 0.01). AG555 (136 mumol.L-1) had little effect on CK II activity.


CONCLUSIONS
Some tyrphostins are potent inhibitors of CK II.
Huang
C
C
Department of Medical Biochemistry, Guangdong Medical College, Zhanjiang, China.
Kang
T B
TB
Liang
N C
NC
D000818:Animals; D047390:Casein Kinase II; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D008099:Liver / Q000737:chemistry / Q000201:enzymology*; D017346:Protein Serine-Threonine Kinases / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D020032:Tyrphostins / Q000494:pharmacology*
D004791:Enzyme Inhibitors; D020032:Tyrphostins; C117081:tyrphostin AG 1109; C117080:tyrphostin AG 114; C117082:tyrphostin AG 1394; C060152:tyrphostin 47; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases