Effects of fructose 2,6-bisphosphate and glucose 1,6-bisphosphate on porcine heart protein phosphatase 2A.
Fructose 2,6-bisphosphate and glucose 1,6-bisphosphate are apparent noncompetitive inhibitors of porcine protein phosphatase 2A2 having Ki values of 0.38 and 0.56 mM, respectively. The inhibitory effects were on the catalytic subunit and were not substrate directed. In addition, fructose 2,6-bisphosphate caused a time-dependent inactivation of phosphatase activity toward phosphorylase a. This inactivation was antagonized by MnCl2. The fructose 2,6-bisphosphate-inactivated enzyme had increased p-nitrophenyl phosphate phosphatase activity. These effects are similar to the known effects of ATP on type 2A phosphatases.
Erickson
A K
AK
Department of Biochemistry, North Dakota State University, Fargo 58105.
Killilea
S D
SD
D000818:Animals; D005635:Fructosediphosphates / Q000494:pharmacology*; D019298:Glucose-6-Phosphate / Q000031:analogs & derivatives*; D005958:Glucosephosphates / Q000494:pharmacology*; D066298:In Vitro Techniques; D009206:Myocardium / Q000201:enzymology*; D010749:Phosphoprotein Phosphatases / Q000037:antagonists & inhibitors*; D010762:Phosphorylase a / Q000378:metabolism; D054648:Protein Phosphatase 2; D013552:Swine
D005635:Fructosediphosphates; D005958:Glucosephosphates; D019298:Glucose-6-Phosphate; C027652:fructose 2,6-diphosphate; C016473:glucose-1,6-bisphosphate; D010762:Phosphorylase a; D010749:Phosphoprotein Phosphatases; D054648:Protein Phosphatase 2